Dissertations / Theses on the topic 'Fish stress'
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1
Dunlop, R. A. "Stress and pain in fish." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269065.
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Millsopp, S. "Pain, Stress and Welfare of Fish." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527874.
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Hashimoto, Hisashi. "STUDIES ON STRESS RESPONSE OF FISH CELLS." Kyoto University, 1998. http://hdl.handle.net/2433/157119.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第7412号
農博第996号
新制||農||763(附属図書館)
学位論文||H10||N3158(農学部図書室)
UT51-98-G341
京都大学大学院農学研究科水産学専攻
(主査)教授 坂口 守彦, 教授 内田 有恆, 教授 宮本 元
学位規則第4条第1項該当
4
Beaumont, Timothy Martin. "Regulation of stress hormone receptors in fish cells." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366436.
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Øverli, Øyvind. "Behavioural and Neuroendocrine Effects of Stress in Salmonid Fish." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5007-5/.
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Linden, Melissa. "The effects of exercise and fish oil on oxidative stress." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/5909.
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Thesis (M.A.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 30, 2007) Includes bibliographical references.
7
Reeves, James Frederick. "The role of stress and dietary micronutrients in fish health." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/2415.
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The overall theme of this thesis has been the study of the effects of well known and potentially novel stressors on fish health and how some of these may be modulated by dietary supplements of micronutrients, using both in vitro and in vivo analysis. In vitro experiments with cultured fish cells (EPC-A1, GFSk-S1) evaluated the potential of niacin and selenium to reduce cytotoxicity and genomic instability (DNA damage) induced by ultraviolet radiation exposure, following assay validation with reference toxins. Whilst cytotoxicity was determined by the neutral red retention (NRR) assay, genomic stability was evaluated by either a standard or modified version of the single cell gel electrophoresis (SCGE) or 'Comet' assay. Niacin as nicotinamide (NAM) significantly reduced levels of UVB induced DNA damage (single strand breaks). Selenium supplements, as sodium selenite or seleno-L-methionine also showed a protective effect against H202, UVA and UVB induced cytotoxicity and oxidative DNA damage. An additional in vitro study was carried out to identify environmental nanoparticles as a potential novel source of stress for fish. Titanium dioxide (Ti02) nanoparticle exposure to GFSk-81 cells caused dose-dependent increases in cytotoxicity (NRR assay) and oxidative DNA damage (Comet assay). These effects were exacerbated by combined exposures of Ti02 with UVA. Electron spin resonance (ESR) and spin trapping suggested that Ti02 induced oxidative stress may be primarily due to the production of hydroxyl radicals (OH). Two in vivo experiments were carried out in order to evaluate the effects of husbandry stress (netting and confinement stress) on antioxidant capacity, immune function and genomic stability in trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) , In both studies on trout and carp, certain health parameters were shown to be sensitive to husbandry stress, and may be useful biomarkers of stress in future studies. Total antioxidant capacity (TAC) was reduced in both carp and trout after stress. Respiratory burst capacity of blood leukocytes was also affected by stress but differently in carp than in trout. In carp, husbandry stress apparently stimulated the production of free radicals by leukocytes whereas in trout it was suppressed. In trout, stress was also shown to increase oxidative DNA damage, as measured by the Comet assay. Health parameters that appeared not to be significantly affected by husbandry stress in this study include SOD activity, ALP activity, red blood cell fragility and complement activity (for carp only). In the second experiment on carp, a 10 week feeding trial was also conducted prior to stress induction to evaluate the potential modulatory effects of selenium, zinc and vitamin E on any husbandry induced stress effects observed. Health parameters were also evaluated pre stress in order to elicit any effects of micronutrient supplementation on health parameters in unstressed fish. Selenium supplementation significantly increased glutathione peroxidase activity post stress, but not pre stress, indicating an increased requirement of selenium in stressed fish. No other differences were observed between dietary treatments for any parameter measured either pre stress or post stress, indicating that levels of selenium, zinc and vitamin E were probably sufficient in the control diet. Further work is needed to enhance our understanding on the interaction between, and the role of, stress and dietary micronutrients in fish health using a suite of assays to monitor all aspects of fish health, both in vitro and in vivo.
8
Takeuchi, Kazuharu. "STUDIES ON THE FISH TAURINE TRANSPORTER INDUCED BY HYPEROSMOTIC STRESS." Kyoto University, 2001. http://hdl.handle.net/2433/150776.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第9005号
農博第1187号
新制||農||821(附属図書館)
学位論文||H13||N3524(農学部図書室)
UT51-2001-F335
京都大学大学院農学研究科応用生物科学専攻
(主査)教授 坂口 守彦, 教授 田中 克, 教授 林 勇夫
学位規則第4条第1項該当
9
Miller, Lana L., and University of Lethbridge Faculty of Arts and Science. "The effects of selenium on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/397.
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Selenium (Se), an essential element, can bioaccumulate and become toxic. The
main toxicity symptom in fish, teratogenicity, is mediated by oxidative stress; however,
little is known about the effect of Se on the physiological stress response (PSR). The
effects of Se on the PSR and oxidative stress parameters were investigated in rainbow
trout, brook trout, and white suckers. The PSR was activated by acute and sub-chronic
laboratory exposures to NaSeO3, but not exposure to environmental levels of Se.
Species-specific sensitivity to Se may be explained by biochemical differences. Rainbow
trout (exhibit oxidative damage with Se exposure) have greater GSH reserves (cycles
with Se causing oxidative stress) than brook trout. Selenium in agricultural drain water
did not accumulate to dangerous levels in white suckers, but additional stressors (e.g.
pesticides) were present. Differences in sensitivity to Se may alter competitive
interactions between species, changing community compositions and putting additional
pressure on threatened species.xiii, 150 leaves ; 29 cm.
10
Zha, Yinghua. "Assembly of Gut Microbial Communities in Freshwater Fish and Their Roles in Fish Condition." Doctoral thesis, Uppsala universitet, Limnologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314235.
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Animal hosts provide associated microorganisms with suitable ecological niches in their intestines. Microbes help their hosts to digest food, protect against pathogens, and influence the host’s metabolisms. Compositional variation of gut microbial communities is common among hosts, and may affect the health status of hosts. Diet and genetic factors are well known to influence the assembly of gut microbial communities. This thesis focuses on disentangling the contributions of factors including host genetics (sex), diet, environment, and other ecological processes to the assembly of gut microbial communities in freshwater fish. The association between gut microbial communities and fish condition is also evaluated in this thesis. Applying metacommunity theory, we found environmental factors including fish habitat, fish species, their diet, dispersal factors including microbes from fish diet, and ecological drift contributed to the assembly of fish gut microbial communities. The proportion of their contribution varied between fish species, where ecological drift explained more in perch than in roach. Under natural conditions fish populations face the risk of predation, which can induce competition and impose predation stress within prey individuals. This can therefore lead to changes in their diet qualities and quantities. In this thesis, it was shown that fish diet in terms of qualities and quantities significantly influenced the overall gut microbial composition, and this influence was dependent on fish sex, a host genetic factor. Predation stress was also suggested to significantly decrease the species richness. Furthermore, when fish were experiencing a diet shift, we showed that different bacterial phyla from novel food had different colonization success in the intestine, and this colonization success was positively influenced by predation stress. Fish condition was suggested in this thesis to be affected by gut microbial composition, especially by the contributions of the bacterial phyla Tenericutes and Actinobacteria.
11
Khosla, Maya. "Relations among biochemical, individual, and community indicators of stress in fish : stream degradation in the Clinch River drainage /." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-02132009-172206/.
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Jones, J. C. "Trade-offs in fish reproduction of the common goby to oxygen stress." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389349.
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Lennard, R. "Environmental stress factors and their effects upon the isolated heart and gut of the flounder." Thesis, Lancaster University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235211.
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Lupica, Samuel J. "Nitrate Toxicity to Common Carp Measured Noninvasively by Novel Enzyme-linked Immunosorbent Assay for Cortisol." University of Toledo Health Science Campus / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=mco1226956326.
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Edmonds, Elizabeth Jane. "Non-invasive measures of stress in ornamental fish in response to husbandry practices." Thesis, University of the West of Scotland, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.732975.
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Jeffrey, Jennifer D. "The Roles of Social Status, Maternal Stress, and Parental Investment in Modulation of Hypothalamic-Pituitary-Interrenal Axis Function in Teleost Fish." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31628.
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In teleost fish, the main glucocorticoid stress hormone, cortisol, is released via the hypothalamic-pituitary-interrenal (HPI) axis. This thesis examined the premise that social status, maternal experience, and reproductive status affect HPI axis function in fish. Social stress in juvenile rainbow trout (Oncorhynchus mykiss) chronically elevates circulating cortisol levels. In this thesis, social subordinance as well as exogenous cortisol treatment resulted in decreased plasma adrenocorticotropic hormone (ACTH) levels, consistent with a negative feedback role of cortisol in modulating HPI axis activity. At the target tissue level, liver glucocorticoid receptor 2 (GR2) mRNA and total GR protein levels were lower in subordinate fish. Although subordinate fish exhibited elevated resting cortisol levels, cortisol and glucose responses to an acute stressor were attenuated. Using an in vitro head kidney preparation, this attenuated cortisol response was attributed to lower ACTH-stimulated production of cortisol. By contrast, dominant status regulated genes associated with cortisol biosynthesis. The consequences of maternal social status on offspring HPI axis function were investigated in zebrafish (Danio rerio). At 48 hours post-fertilization (hpf), when de novo cortisol synthesis becomes possible, larvae of dominant females exhibited lower baseline cortisol levels accompanied by lower mRNA levels of corticotropin-releasing factor and cytochrome P450 side chain cleavage enzyme. Offspring of subordinate females exhibited attenuated stress-induced levels of cortisol at 144 hpf, perhaps as an adaptive response to maternal stress experience. Finally, modulation of HPI axis function was explored as a mechanism underlying attenuation of the stress response during early paternal care in smallmouth bass (Micropterus dolomieu). In response to a stressor, males guarding free-swimming fry but not eggs elevated plasma ACTH and cortisol as well as mRNA levels of key HPI axis genes. These results point to a hypoactive HPI axis in males during early parental care as a mechanism for resistance to stress in these fish. Collectively, the results of this thesis emphasize the adaptive plasticity of the HPI axis. Activity of the HPI axis in teleost fish can be modulated by the individual’s experience (e.g., social status) or circumstances (e.g., parental care), as well as by maternal stress.
17
Massarsky, Andrey. "Characterizing the Biochemical and Toxicological Effects of Nanosilver in vivo Using Zebrafish (Danio rerio) and in vitro Using Rainbow Trout (Oncorhynchus mykiss)." Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30665.
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Many consumer and medical products contain engineered nanomaterials (ENMs) due to their unique properties arising from their small size of <100 nm in at least one dimension. Although ENMs could greatly improve the quality of daily life, concerns for their health and environmental safety emerged in recent years because the same properties that make ENMs beneficial may also render them toxic. The small size allows ENMs’ entrance into the cell where they may attach to biological molecules and membranes, disrupting their function and/or leading to oxidative stress and/or damage.
This thesis focused on silver nanoparticles (AgNPs). Several articles demonstrated that during washing AgNPs are released from the AgNP-impregnated fabrics and could pose a risk to aquatic species. Given that the toxicity mechanisms of AgNPs are yet to be clearly understood this thesis investigated the effects of AgNPs from ‘oxidative stress’ and ‘endocrine disruption’ points of view, using both in vivo and in vitro model fish systems.
A 4 d exposure of zebrafish (Danio rerio) embryos to AgNPs increased mortality, delayed hatching, and increased oxidative stress. The silver ion (Ag+) was more effective in eliciting these effects at equivalent silver concentrations. Moreover, the Ag-chelator cysteine reduced the toxicity of both Ag-types. Despite these effects AgNPs or Ag+ did not affect the ability of zebrafish larvae or adults (raised to adulthood in Ag-free water) to increase cortisol levels, but there were differential effects on the expression of corticotropin-releasing factor (CRF)-related genes, suggesting that other physiological processes regulated by CRF may be impacted.
Furthermore, a 48 h exposure of rainbow trout (Oncorhynchus mykiss) erythrocytes and hepatocytes to AgNPs or Ag+ increased oxidative stress, but Ag+ was more potent. Moreover, AgNPs elevated lipid peroxidation, while Ag+ increased DNA damage, suggesting different modes of action for the two Ag-types. Cysteine treatment reduced the toxicity of Ag+ and AgNPs, while buthionine sulfoximine, which inhibits glutathione synthesis, increased it, suggesting the importance of glutathione in silver toxicity. Finally, AgNPs increased glycogenolysis in trout hepatocytes independently of the beta-adrenoreceptor or the glucocorticoid receptor.
18
Pereira, Ricardo Jorge Silva. "Mercury contamination and oxidative stress responses in the eye of wild fish (Liza aurata)." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14024.
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Mestrado em Toxicologia e EcotoxicologiaEvery animal uses the eyes to monitor the surrounding environment and maintain homeostasis. Mercury (Hg) (including methylmercury - MeHg) is a pernicious and ubiquitous contaminant in natural waters but the assessment of its potential to interfere with fish eyes is an almost unexplored issue. This thesis will contribute to fill this knowledge gap by the evaluation of mercury accumulation in grey mullet eye wall (Liza aurata) together with the assessment of biochemical endpoints related with the oxidative stress status. This approach was complemented by the characterization of environmental contamination profiles (both in water and sediment). The study was performed at Aveiro lagoon (Portugal), where a well-established mercury historical contamination gradient provides a good background for the assessment of mercury accumulation and its toxic effects under realistic conditions. Sampling was conducted in two sites distancing around 10 km, namely: Largo do Laranjo (LAR) located in the most contaminated area, and São Jacinto (SJ) closer to the lagoon inlet and selected as reference site. Keeping in view that water temperature could affect Hg accumulated levels and biochemical responses, sampling was carried out both in winter (February 2013) and summer (June 2013). L.aurata specimens (n=20) were caught at each site/season and eye wall was removed and preserved in the field. Eye wall was analysed for total Hg and MeHg levels, as well as for antioxidant responses (catalase- CAT, SOD – superoxide dismutase, glutathione peroxidase- GPx, glutathione reductase- GR, glutathione–S-transferase - GST) and peroxidative damage (LPO). Inorganic mercury levels were estimated from total mercury and methylmercury levels. Total mercury, inorganic mercury and methylmercury in eye wall were higher at LAR than SJ in winter and summer, reflecting environmental spatial differences of water column and surface sediments. Moreover, fish caught at LAR in winter showed a significant decrease of CAT and SOD, while GST and GR exhibited the same tendency but without statistical support. Peroxidative damage was also recorded as indicated by the LPO enhancement. A much more homogenous spatial pattern was recorded for those biological endpoints in summer, since only the increment of GR and GPx was noticed at LAR. Cause-effect relationships between accumulated mercury (inorganic and methylmercury) were searched by the principal component analysis (PCA). An association between both forms of mercury and GPx and LPO was discerned by PCA. Current data point out the vulnerability of fish eyes to water contaminants, namely mercury. This neurotoxicant can be accumulated in eye wall leading to alterations in the cellular protection against oxidative stress. Such repercussions could eventually compromise fish performance and survival.
Todos os animais usam os olhos para monitorizar o ambiente circundante e manter a homeostase. O Mercúrio (Hg) (incluindo o metilmercúrio - MeHg) é um contaminante pernicioso e omnipresente em águas naturais, mas a avaliação do seu potencial para interferir com olhos de peixe é um problema maioritariamente inexplorado. Esta tese irá contribuir para preencher a lacuna de conhecimento correspondente à avaliação da acumulação de mercúrio na parede do olho de tainha-garrento (Liza aurata), juntamente com a avaliação de parâmetros bioquímicos relacionados com o estado de stresse oxidativo. Esta abordagem foi complementada pela caracterização dos perfis de contaminação ambiental (tanto na água como no sedimento). O estudo foi realizado na Ria de Aveiro (Portugal), onde um gradiente bem estabelecido de contaminação histórica de mercúrio fornece um bom plano de fundo para o estudo de acumulação de mercúrio e os seus efeitos tóxicos sob condições realistas. A amostragem foi realizada em dois locais, distanciados em cerca de 10 km: Largo do Laranjo (LAR), a área mais contaminada, e São Jacinto (SJ), localizado mais perto da entrada da lagoa, tendo sido selecionado como o local de referência. Considerando que a temperatura da água pode afetar os níveis de Hg acumulado e as consequentes respostas bioquímicas, a amostragem foi realizada tanto no inverno (Fevereiro de 2013) e verão (Junho de 2013). Espécimes de L. aurata (n = 20) foram capturados em cada local/estação e o olho foi removido e preservado no campo. Estas amostras foram analisadas em relação a níveis totais de Hg e de MeHg e em relação à resposta antioxidante (catalase-CAT, SOD – superóxido dismutase, glutationa peroxidase-GPx, glutationa redutase-GR, glutationa-S-transferase - GST) e dano peroxidativo (LPO). Os níveis de mercúrio inorgânico foram estimados a partir dos níveis de mercúrio total e metilmercúrio. Mercúrio total, mercúrio inorgânico e metilmercúrio no olho foram superiores em LAR (em relação a SJ) tanto no inverno como no verão, refletindo diferenças espaciais ambientais na coluna de água e no sedimento superficial. Além disso, os peixes recolhidos em LAR no inverno demonstraram uma diminuição significativa na atividade da CAT e SOD, enquanto GST e GR exibiram a mesma tendência, mas sem suporte estatístico. A quantidade de LPO aumentou significativamente, e foram também registados danos peroxidativos indicados pelo aumento de LPO no olho de peixes recolhidos em LAR no inverno. No verão foi registado um padrão espacial muito mais homogéneo para esses parâmetros biológicos, uma vez que apenas o aumento da GR e da GPx foram registados em LAR. As relações de causa-efeito entre acumulação de mercúrio (inorgânico e metilmercúrio) foram pesquisadas através de uma análise de componentes principais (PCA). Uma associação entre as duas formas de mercúrio, GPx e LPO foi evidenciada pelo PCA. Dados atuais apontam para a aparente vulnerabilidade dos olhos de peixe a contaminantes da água, ou seja, mercúrio. Este neurotóxico pode acumular no olho, levando a alterações na proteção celular contra o stresse oxidativo. Tais repercussões eventualmente podem comprometer o desempenho do peixe e a sua sobrevivência.
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Ribas, Cabezas Laia. "Functional genomics in fish: towards understanding stress and immune responses at a molecular level." Doctoral thesis, Universitat Autònoma de Barcelona, 2006. http://hdl.handle.net/10803/3778.
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Aquesta tesis doctoral està basada en estudiar la resposta immunològica dels peixos en models d'estrès i d'activació del sistema immune des la genòmica funcional. L'aplicació de tecnologies moleculars com el Differential Display van permetre identificar y clonar por primera vegada en orades (Sparus aurata) y en altres especies de peix, el gen enolasa. Aquest enzim glucolític s'ha plantejat per primera vegada com un bon marcador molecular per estudiar el benestar dels peixos. Per mitjà de l'ús d'una plataforma de microarrays dissenyada específicament per a salmònids, i altres metodologies biomoleculars, es va comprovar que els nivells d'enolasa eren regulats en diferents teixits y en diferents especies de peix, com també en adverses situacions per l'animal. D'altra banda, s'han estudiat diferents gens immunològics candidats a ser possibles gens per l'estudi del sistema immunològic dels peixos. Aquests gens s'han estudiat a nivell d'expressió en teixits de truites (Oncorhynchus mykiss) mitjançant PCR convencional i PCR quantitativa, i l'ús de metodologies biomoleculars i bioinformàtiques. Entre ells, destaca el factor de transcripció PU.1, un gen indispensable per el desenvolupament de l'hematopoesi. Aquest gen, s'ha clonat i caracteritzat per primera vegada en salmònids. L'expressió de PU.1 s'ha estudiat mitjançant l'ús d'hibridacions in situ en ronyó anterior y en cervell de truita. A més, l'ús de microarray en aquest dos teixits han permès fer un estudi exhaustiu i pioner a nivell de transcriptòmica en peixos. Les anàlisis del xip de microarray, ha revelat que grups de gens s'activen o s'inhibeixen com a conseqüència d'un estrès immunològic.En resum, aquesta tesis doctoral ha aplicat el desenvolupament de noves tecnologies moleculars pioneres en peixos, com el microarray, la clonació de noves seqüències gèniques i la bioinformàtica, per estudiar la genòmica funcional dels peixos en situacions d'activació dels mecanismes d'estrès i del sistema immune.
The main results of the present thesis can be integrated to a better understanding the stress and the immune responses in fish at a transcriptional level. The application of functional genomic tools, which encloses from using simple PCR analysis to more modern, sophisticate and fashionable microarray technique, allowed us to identified transcriptional regulations of certain set of genes which are enhanced or repressed under stress conditions. Our findings contribute to increase knowledge of molecular mechanism involved in coping the stress and immune responses in fish and provides a better understanding of fish physiology when fish health is threatened. Furthermore, thesis results may be interesting for aquaculture which looks for good biomolecular markers that may improve fish production and fish quality. The isolation, characterization and gene expression study with further microarray analysis of the enolase gene, allowed us to describe enolase as a possible biomolecular marker to determine fish welfare. The in situ hybridization study of the hematopoietic transcription factor PU.1, contributed to amplify the knowledge of the development of the fish immune system. Throughout this thesis, DNA sequences and mRNA expression levels of several genes studied, have contributed to enlarged genomic fish database.
In summary, this thesis described from a transcriptional level, gene expression and molecular mechanisms activated or repressed when fish welfare is threatened and contributes to a better understanding of transcriptiomic mechanisms required to cope with the stress.
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Quinn, Amie L., and University of Lethbridge Faculty of Arts and Science. "The impacts of agricultural chemicals and temperature on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbirdge, Faculty of Arts and Science, 2007, 2007. http://hdl.handle.net/10133/676.
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Fish are exposed to multiple stressors in their environment. The interactive
effects of pesticide exposure and increased temperature on the physiological stress
response were investigated in a comparative field study with cold-water (whitefish,
Prosopium williamsoni) and cool-water (sucker, Catostomus) fish from the Oldman
River, Alberta, Canada, and in a laboratory study with rainbow trout, Oncorhynchus
mykiss. Physiogical stress indicators were measured, and exposure to pesticides was
estimated using acetylcholinesterase (AChE) inhibition. Species-specific differences in
AChE activities and responses of the physiological stress axis were detected in whitefish
and suckers, suggesting that whitefish are a more sensitive species to temperature and
pesticide stress. In vivo Dimethoate exposure inhibited AChE activity in various tissues
and disrupted the physiogical stress response. Commercial Dimethoate, in vitro, caused a
decrease in viability and cortisol secretion while pure grade Dimethoate did not. The
results from this study can be used in predictions of fish vulnerability to stress.ix, 137 leaves : ill. ; 29 cm.
21
Maudling, Stuart. "Modulation of the health status of ornamental fish by stress and dietary immuno-stimulants." Thesis, University of Plymouth, 2006. http://hdl.handle.net/10026.1/2761.
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Three trials were conducted to investigate the effects of dietary immuno-stimulant supplementation on various physiological, haematological and immunological parameters of ornamental fish following stress and vaccination. The first series of experiments investigated the mucosal stress response of mirror carp, (Cyprinus carpio), using urinalysis strips and established stress indicators within peripheral blood. A netting stressor, which combined aerial exposure and confinement, of 6 minutes duration was applied and the response of fish was measured 1.5, 3, 5, 24 and 168 hours post-stress. Mucosal haemoglobin and protein were established as consistent indicators of stress and strong relationships could be drawn between them and plasma glucose concentration and peripheral monocytes and lymphocytes counts, firmly establishing them as secondary stress indicators. Visual assessment of the strips was found to overestimate mucosal parameters compared to results obtained using instrument based analysis, but the underlying changes were similar. Further experiments conducted on goldfish, (Carassius auratus), and tilapia, (Oreochromis niloticus x. 0. mossambicus), showed that the mucosal response to stress was conserved between fish species. The second trial investigated the potential of dietary immuno-stimulants to modify the immune status of fish and their response to stress. Fish were fed either a control, beta-glucan (0.2 % w/w), nucleotide (0.2 % w/w) or combined supplement (0.2 % beta-glucan + 0.2% nucleotide) diet for 3 weeks at 1 % BW.dˉ¹ and then to the same stressors as used in Trial 1. Significant stress-induced changes in mucosal protein (p = 0.006), plasma glucose (p = <0.004) and protein concentration (p = <0.003), peripheral lymphocytes (p = 0.001) and monocytes (p = <0.001) and blood NBT reduction (p = <0.001) were observed. Fish fed diets containing immuno-stimulants shower a quicker recovery from the stress-induced hyperglycaemic response than those fed the control diet. Fish that received the beta-glucan diets showed lower blood NBT reduction immediately post-stress than all other diets. The final trial investigated the effects of the control, beta-glucan and combined-supplement diet on the response of fish to vaccination. Fish were fed the diets for 2 weeks prior to and 1 week following IP vaccination against Aeromonas salmonicida at 1.0 % BW.dˉ¹. The immune response was measured every 2 weeks for 12 weeks following vaccination. Vaccination induced a significant stress response as seen by a large hyperglycaemic response (p = <0.05). Significant reductions in peripheral monocyte count were seen following vaccination (p = <0.04). All groups showed elevated NBT reduction at 4 weeks post-vaccination. Serum lysozyme activity showed evidence of long term immuno-suppression following vaccination. No clear effect of the immuno-stimulating diets could be found on any of the physiological or immune parameters tested. The trials conducted found that ornamental fish have a well developed mucosal stress response and this can be used to make inferences about the stress state of fish. The effects of beta-glucans and nucleotides on either the response to stress and immune status were subtle. The nucleotide supplement appeared most effective at reducing the effects of stress, whilst beta-glucans may exert more influence on the immune parameters tested. However, no evidence of synergy between the two types of immuno-stimulant was found in fish fed both immuno-stimulants together.
22
Price, Michael-Anthony. "Effects of intoxication by environmental pollutants on immune responsiveness in carp (Cyprinus carpio L.)." Thesis, University of Essex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242262.
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Chung, Ming-long, and 鍾名朗. "The regulation of lipid peroxidation and pheromone production in medaka fish under exogenous oxidative stress." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209487.
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Liu, Dibo. "Effect of peracetic acid at low concentrations on fish health and water quality." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18516.
Full textAbstract:
Peressigsäure (PES) hat seit kurzem als Desinfektionsmittel in der Aquakultur Einzug gehalten. Gegenüber anderen konventionellen Desinfektionsmitteln besitzt es in niedrigsten Konzentrationen (ca. 1 mg l-1) eine hohe Effektivität. Des Weiteren hat die Anwendung von PES kaum einen negativen Einfluss auf die Umwelt. Die Applikation von PES in Aquakulturanlagen erfolgt direkt über das umgebende Haltungswasser. Dies geht mit einem direkten Kontakt der Mikroorganismen und der Fische mit dem Wirkstoff einher. Aus diesem Grund ist generell ein Einfluss auf die Fischgesundheit und die Wasserqualität zu erwarten. Dieser hypothetische Einfluss ist bislang jedoch unzureichend untersucht worden. In der Praxis werden zumeist zwei Applikationsstrategien verfolgt: 1. Wiederholende Kurzzeitpulsapplikationen mit relative hohen PES-Konzentrationen (1-2 mg l-1) und 2. Die kontinuierliche Applikation mit relative geringen PES-Konzentrationen (≤ 0,2 mg l-1) in der Wasserzufuhr. Die potentiellen Unterschiede dieser zwei Strategien speziell auf die Fischgesundheit und die Wasserqualität sind bislang unklar.
In der vorliegenden Studie wurden Effekte einer PES-Applikation auf die Fischgesundheit und die mikrobielle Aktivität in identischen Durchflussystemen untersucht. Diese Systeme garantieren eine optimale Wasserqualität. Regenbogenforellen wurde als Testorganismen gewählt. Verschiedene Stressparameter, Parameter des oxidativen Stresses, Wachstum, Kiemenhistologie und Parameter der angeborenen Immunantwort wurden zur Bewertung der Fischgesundheit herangezogen. Sauerstoff, pH und die visuelle Biofilmformation wurden kontinuierlich kontrolliert um die mikrobielle Aktivität zu interpretieren. Dazu wurde zweimal wöchentlich mit 1 mg l-1 PES (Pulsbehandlungen) im Haltungswasser und kontinuierlich mit 0,2 mg l-1 PES am Zulauf exponiert und verglichen.
Die Ergebnisse belegen, dass die Pulsapplikationen mit 1 mg l-1 PES, im Gegensatz zur kontinuierlichen Applikation mit 0,2 mg l-1 PES die Fische stressten. Die Fische adaptierten sich jedoch an die PES-Pulsapplikationen. Dies wurde durch nachfolgend weniger heftige Reaktionen der Fische post applicationem, reduzierte Kortisolausschüttungen und unveränderte Reaktionen auf andere Stressoren deutlich. Obwohl die PES-Applikation leichte Hyperplasien in den Kiemen induzierte, war kein Einfluss auf das Wachstum und die angeborene Immunantwort feststellbar. Dies kann als ein Beleg für den fehlenden Einfluss der PES-Exposition auf die Fischgesundheit bewertet werden. PES induzierte unabhängig von den Applikationsstrategien oxidativen Stress in den Fischen. Als Antwort auf die PES-Applikation steigerten die Fische ihre antioxidative Antwort gegen die freien Sauerstoffradikale speziell in den Kiemen und im Serum. Unabhängig von den extrem geringen PES-Konzentrationen in der kontinuierlichen Applikation wiesen die Fische einen geringen oxidativen Stress auf. Der oxidative Stress der Fische in der Pulsexposition war hingegen periodisch nachweisbar. Daraus ist zu schlussfolgern, dass die Fische zwischen den Pulsexpositionen, wenn keine PES vorhanden war, Phasen der Erholung hatten. Das Fehlen dieser Erholungsphase in der kontinuierlichen Expositionsgruppe führte zu einer signifikanten Reduktion der Antiprotease-Aktivität im Serum. Dies impliziert das Risiko einer chronischen Entzündung.
Die antimikrobiellen Effekte sind stark von der PES-Konzentration abhängig. Die Pulsapplikation mit 1 mg l-1 PES hemmte die mikrobielle Aktivität stärker als die kontinuierliche Exposition durch einen stärkeren oxidativen Stress. Dadurch wurde der Biofilm fast vollständig erodiert, und die mikrobielle Sauerstoffsverbrauch und nitrifikation inhibiert. Die PES-Konzentrationen in der kontinuierlichen Exposition waren zu gering um signifikante Effekte auf den Mikroorganismen auszuüben. Des Weiteren kann das PES-Zerfallsprodukte, die Essigsäure und Acetate, eine potentielle Kohlenstoffquelle für die Mikrobiota darstellen. Der daraus resultierende stärkere Biofilm kann durch die Besiedelung mit fakultativen Fischpathogenen eine Gefahr für die Fischgesundheit darstellen. Auf Grund des starken antimikrobiellen Effekts und des geringen Risikos die Fischgesundheit zu beeinträchtigen, werden periodisch regelmäßige PES-Applikationen in Konzentrationen von 1-2 mg l-1 empfohlen.
Effekte einer PES-Applikation auf Spiegelkarpfen und die Wasserqualität in stark belastetem Wasser einer geschlossenen Aquakulturkreislaufanlage (RAS) wurde ebenso untersucht. Die Induktion einer schlechten Wasserqualität erfolge durch den Stopp der Wasserzufuhr zu den Tanks. Simultan zu den Wasserstopps erfolgte eine Applikation mit 1 mg l -1 PES. Die Stressantwort, Kiemenhistologie und die angeborene Immunantwort wurde mit nicht mit PES exponierten Kontrollfischen verglichen. Der Stopp der Wasserzufuhr steigerte die gesamte heterotrophen Bakteriendichte (GHBD) auf das Sechsfache. Im Gegensatz dazu wurde in den Expositionsgruppen die GHBD um 90% gesenkt. Der stark mikrobiozide Effekt der PES-Exposition verbesserte die Gesundheit der Kiemen, verhinderte bakterielle Infektionen welche in den Kontrollgruppen kurzzeitig festgestellt wurden.
Zusammenfassend erhält PES appliziert periodisch in Konzentrationen von 1-2 mg l-1, im Fall der optimalen Wasserqualität, die gute Wasserqualität mit geringfügiger Beeinträchtigung der Fischgesundheit. In der Aquakulturproduktion, in welcher die Wasserqualität meistens durch die hoher Besatzdichte und organischer Belastung verschlechtert wird, verhindern regelmäßige prophylaktische PES-Applikationen Infektionen und begünstigen die Fischgesundheit.Peracetic acid (PAA) has been recently introduced to aquaculture as a sustainable disinfectant. It has great advantages over conventional disinfectants by having high effectiveness and low environmental impact at very low concentrations (around 1 mg L-1). The application of PAA in aquaculture facilities is realized by adding PAA products to the rearing water. This leads to unavoidable exposure of fish and microorganisms (surface-attached and waterborne) to PAA. Consequently, a potential impact of PAA on fish health and microbial activities is expected. This potential impact, however, has been poorly studied. In aquaculture practice, two strategies are broadly used to apply PAA: short term high dose (1-2 mg L-1 PAA) periodic/pulse applications or continuous low dose (≤ 0.2 mg L-1 PAA) application related to the makeup water flow. The potential difference between these two strategies remains unclear, especially concerning their impacts on fish health and water quality. In the present study, the impact of PAA on fish health and microbial activities was tested in identical flow-through systems controlled with optimal water quality. Rainbow trout was selected as the model fish. Various parameters of stress, oxidative stress, growth, gill histology and innate cellular/humoral immunity were measured to indicate fish health. Oxygen, pH and visible biofilm formation were continuously monitored to interpret changes of microbial activities. In addition, the application strategies, biweekly pulse applications of 1 mg L-1 PAA in the rearing water and the continuous application of 0.2 mg L-1 PAA in the inflow, were compared. The results indicate that pulse applications of 1 mg L-1 PAA stressed the naïve fish during the first exposure, while the continuous application not. Fish could progressively adapt to PAA-induced stress, as indicated by less intensive behavioral reaction, reduced cortisol release and unaffected response to another stressor. Although the exposure to PAA induced slight hyperplasia in fish gill, the growth and innate immunity were affected, indicating unaffected overall health. PAA induced oxidative stress in fish, regardless of the application strategies. In response, fish enhanced their antioxidative defense, especially in gill and serum, to scavenge excessive free radicals induced by exposure to PAA. Despite of extremely low PAA concentration measured during the continuous application, the constant input of PAA induced a constant mild oxidative stress to fish. In contrast, the oxidative stress induced by pulse 1 mg L-1 PAA applications was periodic present. Consequently, fish had periodic recovery phases when the pulse PAA applications were absent. The lack of recovery phases in fish exposed to the continuous PAA application resulted in a significant reduction of antiprotease activity in serum. This implies a potential risk of chronic inflammation. The antimicrobial effect of PAA depended on applied concentration. The pulse applications of 1 mg L-1 PAA strongly inhibit microbial activities by inducing a strong oxidative stress. As a result, the biofilm in fish tanks was nearly erased, and the microbial oxygen consumption and nitrification were inhibited. In contrast, the PAA concentration during the continuous application was so low that only a minor antimicrobial effect was observed. In addition, the degradation products, acetic acid and acetate, were beneficial for the biofilm formation by providing organic carbon. The enhanced biofilm may become a potential risk by providing protective shed for opportunistic pathogens. Due to the strong antimicrobial effect and low risk to affect fish health, it’s recommended to apply PAA periodic at high concentrations (1-2 mg L-1) with sufficient intervals. The impact of PAA on fish health and water quality was also tested in a mirror carp recirculating aquaculture system (RAS) challenged with bad water quality. The challenge of bad water quality was realized by transient water stops in fish tanks. Simultaneous to the transient water stops, PAA at 1 mg L-1 was applied. The stress, gill histology and innate cellular immunity were compared in fish with or without simultaneous PAA treatments. The transient water stops caused a 6-fold increase of heterotrophic bacterial density in water, while the simultaneous PAA treatments caused a 90% decrease of heterotrophic bacterial density. The strong antibacterial effect of PAA significantly improved the gill health of fish, and effectively prevented bacterial infections, which were short-term present in fish exposed to transient water stops alone. To sum up, PAA applied periodically at 1-2 mg L-1 in optimal water quality is effective to maintain the water quality at a low cost of scarifying fish health. In production-scale aquaculture facilities, where the water quality is often deteriorated by high stocking density and organic load, regular applications of PAA are especially beneficial to enhance fish health and prevent potential infections.
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Dagar, Anurag. "Supplementation of fish feed with the microalga Parietochloris incisa : effect on stress and disease resistance /." [Sede-Boker, Israel] : Ben-Gurion University of the Negev, 2007. http://aranne5.lib.ad.bgu.ac.il/others/DagarAnurag.pdf.
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Carbajal, Brossa Annaïs. "Cortisol in skin mucus and scales as a measure of fish stress and habitat quality." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/664068.
Full textAbstract:
L’anàlisi del cortisol circulant, el producte final de l’activació de l’eix hipotalàmic-pituïtariinterrenal
(HPI), ha sigut la metodologia més usada en els estudis d’estrès en peixos. Per evitar
els inconvenients inherents al mostreig de sang, el cortisol es pot analitzar de forma menys
invasiva en el mucus cutani dels peixos. Les concentracions de cortisol mesurades en el mucus
han demostrat ser un bon indicador d’estrès en peixos de piscifactoria exposats a diferents tipus
d’estrès agut. Atès que aquest tipus de mostra reflexa l’activitat de l’eix HPI a curt termini, i el
creixent interès de la comunitat científica en estudiar increments crònics de cortisol, recentment
les escates dels peixos han resultat ser un biomaterial amb capacitat de reflectir l’activitat de l’eix
HPI a llarg termini. Al tractar-se de matrius relativament noves, encara falten molts aspectes per
conèixer, principalment aquells relacionats amb la capacitat d’aquestes matrius per reflectir
l’activitat de l’eix. A més, la mesura de cortisol en mucus i en escata de peixos en estat salvatge
podria oferir avantatges tant pràctics com conceptuals. Tot i així, abans d’usar aquestes mesures
en fauna salvatge amb finalitats de conservació i/o gestió, entre d’altres, cal fer una validació
biològica exhaustiva de cada una d’elles. Així doncs, aquesta tesis es va realitzar amb l’objectiu
general de validar la mesura de cortisol en mucus cutani (MCC per les seves sigles en anglès) i
en escates (SCC) i avaluar l’ús d’aquests mètodes com a eines potencials per estudiar la qualitat
de l’hàbitat. Primer, es va validar satisfactòriament el protocol d’extracció d’hormones en
aquestes mostres i la quantificació de cortisol mitjançant enzim immunoassaig. Un cop validada
la part metodològica, es va estudiar la capacitat de les MCC i les SCC per representar
esdeveniments biològics d’interès. Les MCC van demostrar reflectir amb més exactitud les
respostes agudes d’estrès que les cròniques. Els resultats també van revelar que les MCC es
poden usar com una metodologia alternativa i no invasiva per avaluar l’activitat de l’eix HPI del
peix salvatge de riu de l’espècie Squalius laietanus (bagra catalana) en el seu hàbitat natural.
Finalment, les SCC van demostrar oferir informació integrada, retrospectiva i a llarg termini de
l’activitat de l’eix HPI en peixos sotmesos a situacions d’estrès crònic i continuat. Un cop
demostrada la importància biològica d’ambdós matrius, es possible estudiar si aquestes dues
mesures són igualment vàlides per a ser potencialment usades com a bioindicadores de la
qualitat de l’hàbitat. Es va observar que els peixos que residien en habitats amb un grau de
pol·lució diferent presentaven diferències significatives en les MCC, suggerint que aquesta eina
podria ser usada com a bioindicador de la qualitat de l’hàbitat en peixos que habiten aigües
contaminades. Tot i que no es van observar diferències en SCC entre hàbitats, les SCC van
augmentar de forma significativa coincidint amb un període potencialment estressant per
l’espècie. Aquests resultats podrien indicar que les SCC estan més influenciades per períodes
transitoris energèticament exigents que per factors estressants crònics. En general, aquesta tesi
ofereix una base per futurs estudis que usin el mucus cutani i les escates per mesurar les
concentracions de cortisol en peixos, així com també demostra el seu potencial per a ser usada
com a eina d’avaluació d’impacte ambiental en fauna salvatge. A més, obre noves línies de
recerca que s’haurien d’abordar per tal de clarificar encara més l’elevat potencial d’aquestes
matrius com a mesures d’estrès en peixos.El análisis del cortisol circulante, el producto final de la activación del eje hipotalámicopituitario- interrenal (HPI), ha sido la metodología más usada en los estudios de estrés en peces. Para evitar los inconvenientes inherentes al muestreo de sangre, el cortisol se puede analizar de forma menos invasiva en la secreción mucosa cutánea de los peces. Las concentraciones de cortisol en mucus han demostrado ser un buen indicador de estrés en peces de piscifactoría expuestos a diferentes tipos de estrés agudo. Dado que este tipo de muestra refleja la actividad del eje HPI a corto plazo, y el creciente interés de la comunidad científica en estudiar los incrementos crónicos de cortisol, recientemente, las escamas de los peces han resultado ser un biomaterial con la capacidad de reflejar la actividad del eje HPI a largo plazo. Al tratarse de medidas relativamente nuevas, aún faltan muchos aspectos por estudiar, principalmente los relacionados con la capacidad de estas muestras para reflejar la actividad del eje. Además, la medición de cortisol en mucus y en escamas de peces en estado salvaje podría ofrecer ventajas tanto prácticas como conceptuales. Aún así, antes de ser usadas con finalidades de conservación o gestión, entre otras, es necesario hacer una validación biológica exhaustiva de cada una de estas matrices. Por lo tanto, esta tesis se realizó con el objetivo general de validar la medición de cortisol en mucus cutáneo (MCC por sus siglas en inglés) y en escama (SCC), y evaluar el uso de estos métodos como potenciales herramientas para estudiar la calidad del hábitat. En un primer lugar, se validó satisfactoriamente el protocolo de extracción de hormonas en estas matrices y la cuantificación de cortisol mediante inmunoensayo enzimático. Con la metodología validada, estudiamos la capacidad de MCC y SCC para representar eventos biológicos de interés. La MCC demostró reflejar con más exactitud la respuesta aguda de estrés que la crónica. Además, los resultados también revelaron que las MCC podrían ser usadas como una metodología alternativa y no invasiva para evaluar la actividad del eje HPI en peces salvajes de río de la especie Squalius laietanus (bagra catalana) en su hábitat natural. Finalmente, las SCC demostraron ofrecer información integrada, retrospectiva y a largo plazo de la actividad del eje HPI en peces sujetos a situaciones de estrés crónico y continuado. Habiendo demostrado la importancia biológica de ambas matrices, pudimos estudiar si estas dos medidas son igualmente válidas para ser potencialmente utilizadas como bioindicadoras de la calidad del hábitat. Se observó que los peces residentes de hábitats con diferente grado de polución presentaban diferencias significativas en las MCC, sugiriendo que esta herramienta podría ser usada como bioindicador de la calidad del hábitat en peces que habitan aguas contaminadas. Aunque no se detectaron diferencias en las SCC entre hábitats, las SCC aumentaron de forma significativa coincidiendo con un periodo potencialmente estresante para la especie. Estos resultados podrían indicar que las SCC están más influenciadas por periodos transitorios energéticamente exigentes que por factores estresantes crónicos. En general, esta tesis ofrece una base para futuros estudios que utilicen el mucus cutáneo y las escamas para medir las concentraciones de cortisol en peces, a la vez que demuestra el potencial de estas matrices para poder ser usadas como herramientas de evaluación de impacto ambiental en fauna salvaje. Además, abre nuevas líneas de investigación cuyo abordaje puede clarificar, aún más, el elevado potencial de estas matrices como medidas de estrés en peces.
The analysis of circulating cortisol, the end product of the hypothalamic-pituitary-interrenal (HPI) axis activation, has been by far the most common method used as a means to assess fish stress responses. To avoid the drawbacks inherent to blood sampling, cortisol can be lessinvasively analysed in fish skin mucus. The measurement of cortisol concentrations in skin mucus has been shown to be a good stress indicator in farm fish exposed to different acute stressors. Given that this type of sample reflects the short-term activity of the HPI axis, and the growing interest in assessing chronic increases of cortisol, fish scales have been recently recognized as a biomaterial able to reflect the long-term HPI axis activity. There are, however, primary gaps in the knowledge on the degree to which the cortisol content in these samples represents the activity of the HPI axis. In addition, cortisol measurement in both skin mucus and scale samples could offer many practical and conceptual advantages when being applied in wildlife. Nevertheless, before being employed in free-ranging animals for conservation, management or other purposes, each of these new matrices needs to be fully biologically validated. Accordingly, the present thesis was conducted with the general objective to validate the measurement of skin mucus cortisol concentrations (MCC) and scale cortisol concentrations (SCC) and evaluate the applicability of these methods as potential tools to assess habitat quality. We first validated a protocol for hormone extraction in these matrixes and the quantification of cortisol by enzyme immunoassay. After methodological validation, we aimed to examine whether MCC and SCC reflect biological events of interest. Levels of MCC demonstrated to reliably reflect acute stress responses, however, we suggest caution when applying this method for chronic stress assessments. Findings also revealed that MCC could be used as an alternative, non-invasive approach to assess the HPI axis activity in a wild freshwater fish (Catalan chub, Squalius laietanus) within its natural environment. Finally, measurements of SCC proved to reliably offer a retrospective, long-term, integrated measure of the HPI axis activity in fish subjected to long-term continuous stress. Having demonstrated the biological significance of both matrices, it is possible to study whether these measures are equally valid as potential bioindicators of habitat quality. Levels of MCC differed between habitats of different pollution gradient revealing that this metric could be potentially used as a bioindicator of habitat quality in fish residing contaminated streams. Although SCC remained unchanged between habitats, we observed an increase in SCC concurring with a temporarily stressful period, suggesting that transient energetically demanding periods could influence the deposition of cortisol in fish scales. Overall, this thesis offers guidance on the future measurement of cortisol levels in both skin mucus and scales, and its potential use in evaluating environmental impacts in free-living organisms. Moreover, it opens up new relevant research questions that should be addressed to further illustrate the high potential of skin mucus and scale cortisol as a proxy measure for stress.
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De, Polo Anna. "An integrated multidisciplinary approach to study the effects of copper and osmotic stress in fish." Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/9210.
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Since many estuarine zones are impacted by copper contamination, there is an on-going effort to develop Biotic Ligand Models (BLMs) predicting copper toxicity in transitional environments. In the first stage of this project, a critical analysis of the BLM framework identified some aspects of the model that required further investigation. In particular, a BLM for estuaries needed (a) a better characterization of the dissolved organic matter (DOC) and its effect on copper availability, and (b) the inclusion in the model’s equation of a salinity-correction factor modulating the relationship between copper accumulation on the biotic ligand and toxicity. The first issue was addressed by modelling the data produced using a Chelex resin method to determine the labile fraction of copper in samples of mixed riverine and estuarine waters. A refined and simplified BLM equation was then presented, accounting for both the DOC characteristics and the relevance of the osmotic gradient in modulating the relationship between copper accumulation and toxicity. A critical analysis of the literature on copper toxicity and salinity led to the hypothesis that copper-exposed fish are more sensitive to osmotic stresses, as copper interferes with their osmoregulatory pathways. In particular, the cytosolic isoform-2 of the enzyme carbonic anhydrase (CA2) was identified as an osmotic effector protein targeted by copper and involved in osmotic stress response pathways, hence representing a mechanistic link between the combined effects of copper exposure and osmotic stress. To test this hypothesis, two in vivo studies were performed, using the euryhaline fish sheepshead minnow (Cyprinodon variegatus) and applying different rates of salinity changes as a way of dosing osmotic stress. The results showed a disturbance in plasma ion homeostasis after the salinity transitions, but notably the magnitude of the disturbance was greater in the copper-exposed individuals, suggesting a sensitizing effect of copper on the responses of fish to osmotic stress. Gene expression data demonstrated that CA2 is targeted by copper and confirmed the role of the enzyme in osmoregulatory pathways, as further supported by a promoter analysis of the gene coding for zebrafish CA2, which revealed the presence of osmotic-stress related elements. Overall, these results suggest that CA2 is an osmotic effector protein whose response can be activated by a medium level of osmotic stress through a combination of transcriptional and post-translational control circuits.
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Alfonso, Sébastien. "Interactions entre traits de personnalité des téléostéens, environnement et polluants." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG083/document.
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Dans le cadre de cette thèse, nous avons étudié la mise en place de la personnalité, ainsi que sa cohérence en fonction du contexte et des différents stades vie de l’individu et les mécanismes physiologiques associés. La personnalité est apparue cohérente entre les contextes sur de courtes périodes mais ne l’est plus entre les différents stades de vie. Les mécanismes physiologiques de régulation du stress (cortisol et monoamines), ainsi que l’activité et la plasticité neuronale divergent en fonction de l’audace des individus. Ensuite, nous avons étudié les réponses physiologiques et comportementales des téléostéens exposés chroniquement à un mélange de POP (PCB et PBDE), représentatif des conditions environnementales, ainsi que celles de leur descendance non exposée. Des altérations comportementales différentes de la réponse photomotrice larvaire, de l’audace et d’un syndrome comportemental lié à l’anxiété en fonction des générations ont été observées jusqu’à la génération F2 ou F4. Des altérations du niveau d'expression des enzymes responsables de la méthylation de l’ADN ont été également observées suggérant que des mécanismes épigénétiques sont responsables de la transmission de ces altérations chez la descendance. Ensuite, le comportement a été étudié dans des qualités d'eau dégradées afin de mettre en place des indicateurs comportementaux de bien-être pertinents. Les résultats ont montré que suite à la variation de l’oxygénation ou de la teneur en NH3, les individus s’adaptent en diminuant leur activité de nage et la cohésion du groupe. De plus, nous avons observé que le comportement normal de thigmotaxie est inhibé lors de l’exposition à une qualité d’eau dégradée. Cela suggère une hiérarchisation des adaptations comportementales en fonction de la sévérité du stress. Enfin, nous avons étudié les réponses comportementales à une diminution du niveau d’oxygène dans l’eau en fonction de la personnalité : les individus audacieux diminuaient leur activité et leur cohésion de nage avec une plus grande amplitude que les individus timides qui eux diminuaient, avec une plus grande amplitude, le comportement de thigmotaxie. Ces capacités d’adaptation différentes face au stress, en fonction de la personnalité, apportent de nouvelles perspectives pour faire face aux enjeux dans des contextes écologique et aquacoleIn the frame of this thesis, we first studied the establishment of personality in teleost, the consistency across context and different life stages as well as the associated physiological mechanisms. Personality appeared consistent across contexts over a short time period but it was no longer the case over a long period of time, especially between different life stages. Physiological mechanisms of stress regulation, as well as activity and neural plasticity, differed according to individual boldness. Then, we studied the physiological and behavioural responses of teleost fish chronically exposed to an environmentally relevant mixture of POP (PCBs and PBDEs), as well as those of their unexposed offspring. Different behavioural alterations in larval photomotor response, boldness and a behavioural syndrome linked to anxiety have been observed between generations up to the F2 or F4 generations. Alterations in the expression of enzymes responsible of DNA methylation were also observed suggesting that epigenetic mechanisms are involved in the transmission of these behavioural alterations in unexposed offspring. Behaviour was also studied under stressful water quality conditions in order to set behavioural welfare indicators. Results showed that individuals cope with these alterations in oxygen levels or NH3 concentration by decreasing their swimming activity and group cohesion. In addition, we observed that the normal thigmotaxis behaviour was inhibited during exposure to degraded water quality. It suggests a hierarchy of behavioural adaptations depending on stress severity. Finally, we studied the behavioural responses to a decrease in oxygen level according to personality: bold individuals decreased their activity and swimming cohesion with greater amplitude than shy individuals which decreased with higher amplitude thigmotaxis behaviour. These abilities to cope with stress, depending on the personality of teleost fish, bring new perspectives to face both ecological and aquaculture issues
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Mogashoa, M. E. "Seasonal variation in haematological parameters and oxidative stress bio-markers for selected fish species collected from the Flag Boshielo Dam, Olifants River System, Limpopo Province, South Africa." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1188.
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Thesis (M.Sc. (Physiology)) --University of Limpopo, 2015Water is an essential and yet scarce resource, which has a vital role for human use and also serve as a habitat for numerous organisms in aquatic environments. Despite its scarcity there have been many reports indicating that it is continually polluted by domestic, agricultural, mining and other anthropogenic activities; subsequently affecting the health of organisms residing in such water bodies. Fish have been selected as the bio-monitoring species due to its direct interaction with the environment; thereby making it an appropriate model to monitor and evaluate the health status of the environment. The feral population of the alien species, Hypopthalmichtys molitrix (Valenciennes, 1844) commonly known as the silver carp in Flag Boshielo Dam has been considered a healthy population. However, this perception changed considerably after reports of lethargic, dying fish were first noted in 2011. Currently the sporadic deaths amongst mature specimens (>0.7m) persist; and the reason(s) for their demise remains unclear. Therefore, the aim was to employ a seasonal study design to investigate the health status of selected fish species such as H. molitrix in Flag Boshielo Dam by evaluating haematological parameters, oxidative stress biomarkers and bio-accumulation levels of particular transition metals. Seasonal surveys were carried out from February 2012 to January 2013 at Flag Boshielo Dam, Olifants River System, Limpopo Province. The locality surrounding the dam is known to be in an agriculture and mining catchment. Hypopthalmichtys molitrix and Labeo rosae (Steindachner, 1894) commonly known as the rednose labeo were collected with the use of scoop nets, conventional angling gear and gill nets. Following collection, morphometric measurements were taken and blood was collected. The blood samples required for further analysis at the Medical Science Department, University of Limpopo were kept on ice (4˚C). After the collection of all blood samples the specific fish was sacrificed and muscle samples were collected for bio-accumulation analysis and gills and liver samples were collected for the measurement of oxidative stress biomarkers. These tissue samples were rapidly frozen and kept frozen (-85˚C) until further analysis. Haematological parameters from the study reflected a variation amongst comparison of the inter- and intra-species. It was observed that mature H. molitrix suffered from anaemia. The response of glutathione-S-transferase (GST) and thiobarbituric acid reactive substances (TBARS) was relatively constant throughout all seasons when the young (<0.5m) and mature H. molitrix (0.6 – 0.90m) specimens were compared. However, the catalase (CAT) response of mature H. molitrix was dramatically impaired. This would increase their vulnerability to oxidative stress. Bioaccumulation levels of the eleven selected transition elements exhibited various trends. Metals such as Molybdenum (Mo), Vanadium (V), (Chromium) Cr, Cobalt (Co), Zinc (Zn), Cadmium (Cd) and Mercury (Hg) exhibited seasonal bio-accumulation levels that were in support of the various feeding behaviours of the fish species in this study. On the other hand, metals such as Manganese (Mn), Iron (Fe), Copper (Cu), Zinc (Zn), Cadmium (Cd) and Mercury (Hg) also illustrated the potential to be contributing factors in the death of the mature specimens. In conclusion, the findings from this study illustrate the complex nature of metabolic disturbances resulting in the death of mature H. molitrix specimens. It is clear that no single aspect investigated in this study could be solely implicated as the major cause of death. This multifactorial presentation necessitates further haematological assessment focussing on blood cell morphology and pathology, as well as investigations into other oxidative stress biomarkers in liver and gill tissue. In addition, identifying the most appropriate tissue type for future bio-accumulation measurements of transition metals in this feral population is necessitated. It is further suggested that neuro-muscular assessments, focussing on neurotransmitters such as γ-aminobutyric acid (GABA) and acetylcholine (Ach), form part of the investigation into the lethargic behaviour of the mature fish.
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Cardoso, Olívia Albuquerque. "Oxidative stress profiles in brain of fish (Diplodus sargus) upon exposure to mercury in organic and inorganic forms." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15401.
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Mestrado em Biologia Molecular e CelularFish brain demonstrated to be a target organ for organic mercury forms (mainly methylmercury – MeHg). However, there is little information on the neurotoxicity of divalent mercury (Hg(II)) and its ability to accumulate in fish brain. The prevalent information on MeHg is likely based in the perception of its higher toxicity associated with rapid uptake and distribution. Nevertheless, it has been also stated that the different forms of Hg share the same toxic chemical entity and, thus, neurotoxicity depends mainly on the environmental bioavailability. To clarify this research gap, two experiments comprising exposure and post-exposure periods were performed with juveniles of white seabream (Diplodus sargus), namely: experiment A - waterborne exposure to Hg(II) (2 ìg L-1); experiment B - dietary exposure to MeHg (8.7 ìg g-1). Both experiments followed the same experimental design, consisting in 4 exposure periods (E) (days 1, 3, 7 and 14) and 2 post-exposure periods (PE) (days 14 and 28). A control group was kept throughout both experiments in clean seawater or fed with uncontaminated food. At each time, brain was collected for determination of total Hg (tHg) (Experiment A), MeHg (experiment B) and oxidative stress endpoints (both experiments). Though Hg accumulation reached maximum values in brain of both experiments after 14 days of exposure, the highest levels were reached upon exposure to MeHg (7.0 ìg g-1 vs. 1.4 ìg g-1 for HgCl2). Interestingly, fish brain exposed to HgCl2 was not able to eliminate Hg, while MeHg levels decreased significantly in the post-exposure period (to a mean of 3.5 ìg g-1). Moreover, there was a poor activation of antioxidant defenses in fish brain exposed to Hg(II), mainly characterized by increase of superoxide dismutase (SOD) and glutathione reductase (GR) activities. The low protection afforded by antioxidants (confirmed by glutathione peroxidase (GPx) activity decrease) was probably on the basis of oxidative damage, as revealed by the enhancement of protein carbonyl groups in exposure and post-exposure periods. MeHg accumulation led to a different scenario, mainly characterized by an activation of antioxidant defenses (SOD, catalase (CAT), GPx, glutathione S-transferase (GST), total glutathione content (GSHt)) that were able to prevent oxidative damage on proteins and lipids. Despite the higher accumulation of MeHg in fish brain, there was a higher vulnerability of fish brain to Hg(II), depicted in the occurrence of oxidative damage and less responsiveness of the antioxidant systems. Thus, Hg(II) revealed a higher neurotoxicity potential, pointing out the relevance to consider this Hg form, together with MeHg, in further studies concerning wildlife and human health.
O cérebro de peixes mostrou ser um órgão-alvo de varias formas orgânicas de mercúrio (Hg), principalmente metilmercurio (MeHg). Pelo contrario, o conhecimento da neurotoxicidade do mercúrio divalente . Hg(II) . e a sua capacidade de acumulação em cérebro de peixes e muito escasso. A prevalência de informação sobre a neurotoxicidade de MeHg baseia-se, provavelmente, na perceção da sua elevada toxicidade, associada há sua rápida entrada no organismo e elevada distribuição. No entanto, foi também observado que as diferentes formas de Hg partilham a mesma forma toxica e, por isso, a sua neurotoxicidade dependera essencialmente da biodisponibilidade ambiental. De modo a contribuir para colmatar esta lacuna cientifica, realizaram-se 2 experiencias com sargos juvenis (Diplodus sargus), que compreenderam períodos de exposição e pós-exposição, designadamente: experiencia A . exposição via agua a Hg(II) (2 ƒÊg L-1); experiencia B . exposição via alimento a MeHg (8,7 ƒÊg g-1). Ambas as experiencias seguiram o mesmo desenho experimental, consistindo em 4 períodos de exposição (E) (dias 1, 3, 7 e 14) e 2 períodos de pós-exposição (PE) (dias 14 e 28). Foi mantido um grupo controlo em agua do mar e ração não contaminada ao longo de toda a experiencia. Em cada tempo de exposição e pos-exposição foram colhidos cérebros de D. sargus para determinação de Hg total (tHg) (experiencia A), MeHg (experiencia B) e parâmetros de stress oxidativo (ambas as experiencias). O Hg(II) também foi quantificado no cérebro dos peixes expostos a MeHg. Embora em ambas as experiencias o Hg total tenha atingido o seu máximo de acumulação ao dia 14 de exposição, os níveis maiores correspondem a exposição a MeHg (7,0 ƒÊg g-1 vs. 1,4 ƒÊg g-1 para Hg(II)). Os cérebros de peixes expostos a Hg(II) não eliminaram Hg, enquanto os níveis de MeHg diminuíram significativamente no período de pos-exposição (em media para 3,5 ƒÊg g-1). Alem disso, verificou-se uma reduzida ativação das defesas antioxidantes nos cérebros de peixes expostos a Hg(II), caracterizada principalmente pelo aumento das atividades de superóxido dismutase (SOD) e glutationa redutase (GR). A baixa proteção antioxidante (reforçada pela diminuição da atividade de GPx (glutationa peroxidase)) esteve provavelmente na base do dano oxidativo, tal como revelado pelo aumento dos grupos carbonilo (indicador de dano oxidativo em proteinas) ao longo dos períodos de exposição e pos-exposição. A exposição de D. sargus a MeHg conduziu a um cenário diferente, principalmente caracterizado pela ativação de defesas antioxidantes (SOD, catálase (CAT), GPx, glutationa S-transferase (GST), glutationa total (GSHt)) que conseguiram prevenir o dano oxidativo em lípidos e proteínas. Apesar de se ter registado uma maior acumulação de MeHg no cérebro de D. sargus, verificou-se uma maior vulnerabilidade do cerebro a Hg(II), tal como evidenciado pela ocorrência de dano oxidativo e pela menor resposta do sistema antioxidante. Globalmente, o Hg(II) revelou ter um maior potencial neurotoxico, o que aponta para a relevância de considerar esta forma de Hg, juntamente com o MeHg, em futuros estudos focados na saúde animal e humana.
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Barkerud, Rickard. "Welfare Evaluation of Stunning Practices for Farmed Fish in the European Union." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-107042.
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An optimal method for stunning animals before slaughter should result in instantaneous and irreversible insensibility. Today, there are various stunning and slaughter practices used around the world for farmed fish. With aquaculture being a growing food sector, the welfare of the animals used has become increasingly important in the consciousness of consumers, researchers and regulatory bodies. With growing research into the subject matter, an overview to summarize and examine how these practices impact on the welfare of the fish, and how well they conform to animal welfare legislation, is warranted to minimize the suffering of farmed fish. Stunning practices used in aquaculture include methods such as electrical and percussive stunning, carbon dioxide and asphyxiation. Each with its own level of effectiveness in terms of how fast the method results in loss of consciousness, whether or not the effect is reversible and how the welfare of the fish is affected as determined by behavioural and physiological stress responses. It was concluded that there is no unambiguous answer as to which stunning method is optimal in regard to animal welfare in modern day aquaculture. The optimal method for a given facility is influenced by factors like practicalities relating to each individual method as well as legislation on EU and national level. Suggestions were made for future research.
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Abdalla, Raisa Pereira. "Efeito do alumínio e manganês, em pH ácido, nos parâmetros de estresse oxidativo em machos de Astyanax altiparanae (Characiformes: Characidae)." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/41/41135/tde-19012016-094105/.
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Muitos metais como alumínio e manganês, quando adicionados nas águas pela atividade antrópica, podem produzir efeitos deletérios nos organismos. Estes metais causam alterações no sistema fisiológico, como alterações metabólicas, respiratórias, além de serem capazes de aumentar a produção das espécies reativas de oxigênio (EROs), o que podem alterar a atividade das enzimas antioxidantes que atuam no estresse oxidativo. O presente estudo investigou se a exposição aguda por 24 e 96 horas ao alumínio (Al) e manganês (Mn) em pH ácido, de forma isolada ou combinada (Al+Mn), são capazes de causar estresse oxidativo em machos sexualmente maduros de Astyanax altiparanae, e também verificou se 96 horas em água livre de metais, eram suficientes para que estes animais se recuperassem dos possíveis efeitos deletérios destes metais. A exposição ao pH ácido alterou os níveis da atividade da SOD branquial no período agudo (96h) e a atividade desta enzima não retornou aos níveis do controle no período de recuperação. A exposição ao Al aumentou a concentração de GSH (24h) nas brânquias no período agudo, retornando aos níveis do controle (96h). O Mn não alterou os níveis dos parâmetros de defesas estudados, no entanto isso ocasionou ao aumento de malondialdeído (MDA) nas células, acarretando em peroxidação lipídica. Os animais expostos ao Al+Mn combinados apresentaram diversas variações, aumentando a concentração de GSH e atividade GPx no período agudo nas brânquias. Apesar da tentativa de defesa no período agudo, o período de recuperação apresentou alterações na atividade da catalase (96h), aumento da metalotioneína (24h) e altos níveis de lipoperoxidação (96h) hepática. Os metais estudados, independentemente do pH ácido, podem ser considerados indutores do estresse oxidativo em machos de A. altiparanae, influenciando na atividade enzimática e ocasionando alterações fisiológicas que podem interferir na reprodução. Os resultados obtidos no presente estudo ajudarão a entender os mecanismos de estresse oxidativo induzido pelos metais (Al e Mn) e sua possível influência na reprodução de A. altiparanaeMany metals such as aluminum and manganese, when added in the waters by human activity, can produce deleterious effects in organisms. These metals cause changes in the physiological system, such as metabolic, respiratory disorders, as well as being able to increase the production of reactive oxygen species (ROS), which can alter the activity of antioxidant enzymes that act on oxidative stress. This study investigated whether acute exposure for 24 and 96 hours to aluminum (Al) and manganese (Mn) in acidic pH, isolated or combined (Al + Mn), are able of causing oxidative stress in sexually mature Astyanax altiparanae males, and also if the exposition for 96 hour in free metal water was enough for these animals to recover from the possible deleterious effects of these metals. The acidic pH altered levels of gill SOD activity in the acute period (96 hours) and the activity of this enzyme did not return to control levels during the recovery period. The exposition to Al increased the GSH levels (24h) in the gills in the acute period, returning to control levels (96h). The exposition to Mn did not alter the levels of the studied defence parameters, however this led to an increase in cell MDA (malondialdehyde), resulting in lipid peroxidation. The animals exposed to Al + Mn combined presented several variations in the measured parameters, increasing the concentration of GSH and GPx activity in the acute period (24h) in the gills. Despite the defence attempt in the acute period, the recovery period showed changes in catalase activity in the liver (96h), increased hepatic metallothionein (24h) and higher levels of hepatic lipid peroxidation (96h). The metals studied, irrespective of water at acid pH, they can be considered inducers of oxidative stress in A. altiparanae males influencing enzyme activity and causing physiological changes that can interfere with reproduction. Our findings will help to understand the mechanisms of oxidative stress induced by metals (Al and Mn), and its effects in A. altiparanae reproduction
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Ho, Cheuk Hin. "Effects of osmotic stress on molecular responses of gill cells from Japanese eels, Anguilla Japonica." HKBU Institutional Repository, 2021. https://repository.hkbu.edu.hk/etd_oa/885.
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Japanese eels (Anguilla japonicas) are snakelike fishes living in waters in the Asian region. In contrast to most fishes which are stenohalines that can only live in waters with a narrow range of salinity, Japanese eels are classified as euryhalines that can habitat in a broad range of salinity. As the lifecycle of Japanese eels consists of stages across fresh and seawater districts, a well-developed osmoregulation mechanism is needed to balance the intra- and extra- cellular osmolarity of the fishes throughout the seawater acclimation process. While fish gills are one of the organs that separating the ambient water and the inner body fluid of the fish, the fish gills of the Japanese eels have been studied as one of the most crucial organs for osmoregulation purposes. Yet, the osmoregulation and survival strategies of Japanese eels under hyperosmotic stress has not been fully elucidated. In chapter 2, this study has performed a transcriptome study on the ex vivo gill filament model of the Japanese eel to profile the molecular responses after a hypertonic treatment of 4 hours or 8 hours. The experiment is aimed to mimic the gill cells exposed to seawater in the seawater acclimation process of Japanese eels. A profile of differential expressed genes (DEGs) has been revealed that 577 DEGs were commonly upregulated and 711 DEGs were commonly downregulated in both 4- and 8-hours hypertonic treatment. Functional analysis and annotation have been processed with these DEGs, including Ingenuity Canonical Pathways analysis and gene ontology. These analyses have revealed that the cellular homeostasis of the gill cells has been disrupted and cell death responses has been induced by osmotic stress. The results have raises a concern that the maintenance of cellular viability and a cell death regulation mechanism are needed for the fishes to survive in the early stage of seawater acclimation. In chapter 3, this chapter demonstrated that gill cells in Japanese eels are susceptible to apoptosis when they are exposed to hyperosmotic treatments in both in vitro gill cell and the ex vivo gill filament model. To maintain the viability of the gills cells, two inhibitors of apoptosis, XIAP, and survivin, were seen to be expressed in gills cells. The expression of XIAP and survivin were upregulated by dexamethasone, which is an agonist mimicking the effect of cortisol on fishes in seawater acclimation. Meanwhile, the expression levels of the apoptosis executor, caspase 3, were downregulated. These data suggested that with the regulation of cortisol express in the fishes, XIAP and survivin are effective apoptosis regulators in the gill cells of Japanese eels. The study has demonstrated the molecular responses of the gills of Japanese eels exposed to hyperosmotic stress at the transcriptional level and post-translational level by using transcriptome studies and protein study respectively. The study has paved cell death regulation to be another the key field to study in understanding the ability of salinity tolerance in euryhalines.
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Wilkes, Luanne. "Potential environmental enrichment for zebrafish used in regulatory toxicology." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3456.
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The aim of environmental enrichment is to alter the environment of a captive animal in a way that results in improved mental and physical welfare. The technique has been utilised effectively for many years for captive mammals in a variety of settings. However, until now it has never been considered as a way of improving the welfare of aquatic animals such as fish. Fish that are used in regulatory toxicology studies are at present maintained solely in barren tank environments. Little is known about how these types of environments affect the well-being of the animals residing there and whether they impact either physiological heath or behavioural repertoire. This thesis aims to address this gap in the knowledge regarding the potential for environmental enrichment to improve the welfare of fish used in regulatory toxicology. More specifically it looks at two types of enrichment and the effects of these on the commonly used model species, the zebrafish (Danio rerio). The first type of enrichment studied was glass rod structures of varying heights provided to increase tank complexity and provide refuge. The glass structures did not produce any quantifiable benefits in unstressed fish and appeared to delay the formation of stable social hierarchies. When fish were stressed by a period of chasing, the presence of the glass rods appeared to reduce the magnitude of the cortisol response. Whilst this could be viewed as a potential benefit, it was felt that it would not outweigh the costs of this type of enrichment. The second type of enrichment studied was provision of airstones. Again, no clear evidence was found that fish in tanks with airstones experienced an improvement in welfare. The main observation was the vast increase in mortality in tanks containing these airstones, in particular, those of a smaller size. Regardless of the physiological cause underlying this result, this can only be viewed as a negative consequence and one that appears to rule out airstones as an effective form of enrichment for this species and strain of fish. It was also observed that both stress and the presence of enrichment influenced the absolute deviation from the mean in several endpoints. Since changes in endpoint variation will have effects both on the number of animals required to statistically measure environmentally relevant effects this is a factor that should be considered when researching methods of environmental enrichment. Finally, results from these studies suggest the possibility that laboratory zebrafish do not require the addition of environmental enrichment to tanks in order to promote maximum welfare. Furthermore, as considerable costs would be involved in implementing many types of enrichment (relating to manufacture, cleaning, incompatibility of results with previous studies etc.) it is likely that observed benefits would have to be both substantial and well established in order for changes in regulatory guidelines to take place. For a species such as zebrafish that are extremely easy to breed and maintain in the laboratory with minimal amounts of disease, social problems or mortalities, it may be that current conditions are satisfactory.
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Schjolden, Joachim. "Stress Coping Strategies in Rainbow Trout (Oncorhynchus mykiss)." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6132.
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Pon, Lucas Benjamin. "The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/726.
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In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis.
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Barretto, Adriana Beatriz. "Estresse e memória Efeito do estresse agudo e crônico na retenção da memória em diferentes perfis de personalidade em tilápias-do-Nilo /." Botucatu, 2018. http://hdl.handle.net/11449/153772.
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Orientador: Percília Cardoso GiaquintoResumo: CAPÍTULO 1 – Neste estudo avaliamos o efeito do estresse agudo e crônico na memória de aprendizagem de tilápias-do-Nilo com diferentes perfis de personalidade. Inicialmente definimos a personalidade dos peixes através de testes de objeto novo e exposição a um predador, classificando-os em shy (tímido) ou bold (ousado) e em seguida estes indivíduos foram condicionados por um método simples de condicionamento clássico como forma de aprendizagem para posterior avaliação da memória. Os peixes shy foram então divididos em dois grupos, sendo que em um deles os peixes foram diariamente estressados por hipóxia, perseguição com rede ou confinamento (grupo shy-experimental) por 64 dias consecutivos, enquanto que no outro grupo os peixes permaneceram apenas isolados (grupo shy-controle) pelo mesmo período de tempo. O mesmo procedimento foi adotado com os peixes classificados como bold. Nesse mesmo período, testes de memória foram realizados em dias específicos, tanto nos grupos experimental quanto nos grupos controle. Ao final do experimento, reavaliamos se as personalidades se mantiveram. Obtivemos que o estresse agudo afetou a memória de aprendizado em peixes, principalmente em indivíduos com perfil de personalidade shy. CAPÍTULO 2 – Aqui desenvolvemos uma metodologia simples de condicionamento clássico facilmente aplicável em laboratórios de experimentação com peixes, quando comparados aos métodos descritos na literatura atual, onde os estímulos geralmente aplicados para condicioname... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: CHAPTER 1 - In this study we evaluated the effect of acute and chronic stress in learning memory of Nile tilapia with different personality profiles. Initially we defined the personality of the fish through the testo f new object and exposure to a predator, classifying them as shy or bold, and then these individuals were conditioned by a simple method of classical conditioning as a way of learning to evaluation of memory. The shy fish were divided into two groups, and in one group the fish were daily stressed by hypoxia, net chase or confinement (shy-experimental group) for 64 consecutive days, while in the other group the fish remained only isolated (shy-control group) for the same time period. The same procedure was adopted with fish classified as bold. During the same period, memory tests were performed on specific days, in both groups, experimental and control group. At the end of the experiment, we reevaluated whether the personalities held. We found that acute stress affected learning memory in fish, especially in individuals with shy personality profiles. CHAPTER 2 - Here we develop a classical conditioning methodology easily applicable in fish experimentation laboratories when compared to the methods described in the current literature, where the stimuli generally applied for conditioning (sound or light) can interfere with the responses of experimental animals present in the same laboratory. For this conditioning, we isolate the fish in individual aquariums and intro... (Complete abstract click electronic access below)
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Ims, Stine. "The Efficacy and Stress-Reducing Capacity of MS-222, Benzoak and Aqui-S for the Ornamental Cichlid Fish, Metriaclima estherae." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12760.
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The financial crises and global change have caused setbacks to the improvements in many undeveloped countries. To be able to achieve the Millennium developmental goals within 2015, it will require a higher effort. Sub-Saharan African countries show the slowest economic growth and have experienced the highest setbacks. Malawi is one of these countries and is struggling with a high share of poverty and poverty related issues. Trade is believed to be the most prominent tool to fight world poverty, as it will provide economic growth and employment. Cichlid fishes from Lake Malawi are popular ornamentals for hobby aquarists world wide, representing yearly turnover of 340 million US dollars. It is suggested that ornamental Malawi cichlids can be developed into an industry benefiting country and the local poor people. This can be achieved without pressure upon the lake biodiversity if the wild-collected fishes are used for breeding purpose and not for export. To be able to deliver a high quality fish, it will be necessary to establish proper handling strategies that will ensure fish health and welfare. Stress from handling procedures is known to have negative impact on fish growth, reproduction, immune function and survival. Anesthetics may be a useful tool during handling procedures of the fish, as it can reduce the perception of the stressor and thus prevent activation of the hypothalamus-pituitary-interrenal (HPI) axis. In this study the three commercial anesthetics; MS-222, Benzoak® and Aqui-S were evaluated for; (1) anesthetic efficacy, (2) safety margin, (3) prolonged exposure and (4) stress-reducing capacity on the Malawi cichlid, red zebra (Metriaclima estherae). The overall results show that concentration of 150 mg/L MS-222, 120 mg/L Benzoak® and 50 mg/L Aqui-S gave satisfying introduction and recovery time for anesthesia. Both MS-222 and Aqui-S gave high safety margins as no fish mortality was recorded after anesthetic exposure for 30 minutes. Benzoak® gave a lower safety margin as there was recorded 50 % mortality following 10 minutes exposure. High mortality rate and sign of insufficient blockage upon the red zebra fish, suggested that prolonged exposure to the tested sedative dosages did not benefit the fish. MS-222 exposure reduced the stress response while Benzoak® and Aqui-S seemed to self-induce an increase in plasma cortisol concentration after anesthetic exposure. In conclusion; for short-term treatment on red zebra fish, a concentration of 150 mg/L MS-222 is recommended.
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Gause, Brian. "REPLACEMENT OF FISH MEAL WITH ETHANOL YEAST IN THE DIETS OF SUNSHINE BASS: EFFECTS ON PRODUCTION PERFORMANCE AND STRESS TOLERANCE." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/341.
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Numerous alternatives to fish meal (FM) have been investigated by aquaculture nutritionists in order to reduce aquacultures reliance on this finite and costly resource. Traditional protein alternatives derived from terrestrial plants and animals have shown varying success and limitations. In order to produce effective, least cost feeds new alternative proteins must be investigated. Ethanol yeast (EY), a co-product of bio-ethanol production may be a novel protein source. The increasing capacity of the bio-ethanol industries has made EY an increasingly available commodity. However, no studies have been done to evaluate ethanol yeast as a FM replacement in diets of carnivorous fish. Accordingly the objectives of this trial were to evaluate the suitability of EY as a FM alternative in aquafeeds in terms of production performance of sunshine bass. Then based on the results of the first feeding trial, identify any limitations to increased implementation of EY and undesirable effects on physiological robustness of sunshine bass. The first feeding trial using feeds in which EY replaced 0%, 25%, 50%, 75% and 100% of the FM protein from a 30% FM basal diet found that up to 75% of the FM protein could be replaced without significant effects on production performance. Fish reared on the 15% FM treatment (50% replacement) exhibited significantly higher weight gain than the control treatment (30% FM). Low intake in the complete replacement treatment (0% FM) indicated poor palatability. A second trial was conducted using the 15%, 7.5% and 0% FM treatments (50%, 75% and 100% replacement levels respectively), with and without the addition of a palatant in an effort to increase intake. A stress challenge was conducted at the end of the trial to measure dietary effects on physiological robustness. Production performance followed the same trends as the first trial with the 15% FM and 7.5% FM treatments being similar. Whole carcass composition was significantly affected by increasing EY inclusion. Unlike the first trial survival for the 0% FM treatments was significantly affected during the second trial, with an increase in cannibalism and starve outs being noted. Dietary inclusion of EY had no significant effects on hematology before or after stress. Stress however, did significantly affect glucose and lysozyme levels. Cortisol was uncharacteristically high in unstressed fish. Further studies are needed to better determine utilization and digestibility of EY based feeds as well as their effects on hematology at rest and after stress. Based on the results of this study however, the optimal FM inclusion level in EY based feeds is between 75 g/kg and 150g/kg.
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Chow, Sheung Ching. "The characterization of hyperosomotic stress-induced signaling cascades and the downstream effectors in primary gill cell culture of Japanese eels, Anguilla japonica." HKBU Institutional Repository, 2010. http://repository.hkbu.edu.hk/etd_ra/1182.
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Hermann, Bernd Timo [Verfasser]. "Chronic stress in fish - Investigation of the cellular response to persistent environmental hypercapnia and malnutrition in two marine fish species, turbot (Psetta maxima) and cod (Gadus morhua) via RT-qPCR / Bernd Timo Hermann." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1173163255/34.
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Barretto, Adriana Beatriz [UNESP]. "Estresse e memória: Efeito do estresse agudo e crônico na retenção da memória em diferentes perfis de personalidade em tilápias-do-Nilo." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153772.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
CAPÍTULO 1 – Neste estudo avaliamos o efeito do estresse agudo e crônico na memória de aprendizagem de tilápias-do-Nilo com diferentes perfis de personalidade. Inicialmente definimos a personalidade dos peixes através de testes de objeto novo e exposição a um predador, classificando-os em shy (tímido) ou bold (ousado) e em seguida estes indivíduos foram condicionados por um método simples de condicionamento clássico como forma de aprendizagem para posterior avaliação da memória. Os peixes shy foram então divididos em dois grupos, sendo que em um deles os peixes foram diariamente estressados por hipóxia, perseguição com rede ou confinamento (grupo shy-experimental) por 64 dias consecutivos, enquanto que no outro grupo os peixes permaneceram apenas isolados (grupo shy-controle) pelo mesmo período de tempo. O mesmo procedimento foi adotado com os peixes classificados como bold. Nesse mesmo período, testes de memória foram realizados em dias específicos, tanto nos grupos experimental quanto nos grupos controle. Ao final do experimento, reavaliamos se as personalidades se mantiveram. Obtivemos que o estresse agudo afetou a memória de aprendizado em peixes, principalmente em indivíduos com perfil de personalidade shy. CAPÍTULO 2 – Aqui desenvolvemos uma metodologia simples de condicionamento clássico facilmente aplicável em laboratórios de experimentação com peixes, quando comparados aos métodos descritos na literatura atual, onde os estímulos geralmente aplicados para condicionamento (som ou luz) podem interferir nas respostas dos animais experimentais presentes no mesmo laboratório. Para tal condicionamento, isolamos os peixes em aquários individuais e introduzimos um jato de água em cada aquário (sem que os peixes pudessem perceber a presença do pesquisador) causando movimentação da água (estímulo condicionado) neste local específico do aquário. Em seguida, um pellet de ração (estímulo incondicionado) foi introduzido no mesmo local da movimentação da água (novamente sem que os peixes pudessem perceber a presença do pesquisador). Esses procedimentos foram realizados durante 20 dias seguidos, 4 vezes ao dia. Obtivemos que após 14 dias de condicionamento todos os peixes associaram estímulo condicionado e incondicionado, confirmando a efetividade deste método simples e sem interferência nos demais animais experimentais presentes no ambiente.
CHAPTER 1 - In this study we evaluated the effect of acute and chronic stress in learning memory of Nile tilapia with different personality profiles. Initially we defined the personality of the fish through the testo f new object and exposure to a predator, classifying them as shy or bold, and then these individuals were conditioned by a simple method of classical conditioning as a way of learning to evaluation of memory. The shy fish were divided into two groups, and in one group the fish were daily stressed by hypoxia, net chase or confinement (shy-experimental group) for 64 consecutive days, while in the other group the fish remained only isolated (shy-control group) for the same time period. The same procedure was adopted with fish classified as bold. During the same period, memory tests were performed on specific days, in both groups, experimental and control group. At the end of the experiment, we reevaluated whether the personalities held. We found that acute stress affected learning memory in fish, especially in individuals with shy personality profiles. CHAPTER 2 - Here we develop a classical conditioning methodology easily applicable in fish experimentation laboratories when compared to the methods described in the current literature, where the stimuli generally applied for conditioning (sound or light) can interfere with the responses of experimental animals present in the same laboratory. For this conditioning, we isolate the fish in individual aquariums and introduce a jet of water into each aquarium (without the fish could perceive the presence of the researcher) causing water movement (conditioned stimulus) in this specific aquarium site. Then a feed pellet (unconditioned stimulus) was introduced in the same place as the water movement (again without the fish being able to perceive the presence of the researcher). These procedures were performed for 20 consecutive days, 4 times daily. We obtained that after 14 days of conditioning all the fish associated conditioned and unconditioned stimulus, confirming the effectiveness of this simple method and without interference in the other experimental animals present in the environment.
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Schorer, Marianne. "Utilização do 'beta' - glucano sobre o desempemho produtivo, indicadores de estresse, perfil hematológico e sobrevivência do pacu (Piaractus mesopotamicus) /." Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/86719.
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Resumo: Em peixes, o 'beta'- glucano apresenta uma potente função imunoestimulante sendo cada vez maior a sua utilização como suplemento alimentar, aumentando significantemente a resistência à exposição infecciosa. Este prebiótico tem função de prevenir a colonização de patógenos por intensificar a ativação de macrófagos, proporcionando benefícios ao trato gastrointestinal e resultando em melhor desempenho e resistência a doenças. Este estudo teve a finalidade de avaliar os efeitos do 'beta' - glucano adicionado às rações peletizadas e extrusadas sobre o desempenho produtivo, indicadores de estresse, perfil hematológico e sobrevivência do pacu. Este experimento foi conduzido no Laboratório de peixes ornamentais, do Centro de Aqüicultura da UNESP (CAUNESP), em Jaboticabal, São Paulo. Foram utilizados 640 juvenis de pacu, com 24,7 ± 2,0 g, distribuídos em 32 aquários de vidro (130L). Os parâmetros físico - químicos da água foram mensurados quinzenalmente. Os peixes foram alimentados duas vezes ao dia, uma pela manhão e outra ao fim do dia. Os experimentos apresentaram um delineamento experimental inteiramente casualizado em esquema fatorial 2 x 4, utilizando níveis de inclusão do 'beta'- glucano de: 0 (controle), 0,1%, 0,2% e 0,3% por kg/ ração. Os níveis de'beta'-glucano avaliados neste estudo, não proporcionaram ganhos significativos no desempenho produtivo de juvenis de pacu, porém o tratamento 0,3% apresentou melhores resultados no GP, PF e TCE. A administração do 'beta'- glucano na dieta, durante todo período experimental, provocou alterações nos parâmetros hematológicos e indicadores de estresse do pacu. Os peixes alimentados com o 'beta'-glucano apresentaram maior resistência à infecção da bactéria A. hidrophila. Sendo assim, o tratamento 0,1% apresenta um custo/kg inferior e garante eficácia na saúde de juvenis de pacu.Abstract: In fish, glucano has shown a potent immunostimulant function. The use of glucano is increasing significantly the resistance to diseases after infectious exposition. This prebiotic may be prevent the bacterial colonization, and activated macrophages, been beneficial to the digestive tract, resulting in better performance and disease resistance. This study will evaluate the glucano effects added in palletized and extruded diets of fish, analyzing fish perfOrmance, stress indicators, hematological profile and survival of pacu. This study was driven in Laboratory of ornamental fish, on Centro de Aqüicultura of UNESP (CAUNESP), in Jaboticabal, São Paulo. Were used 640 pacu juveniles, with 24,7 ± 2,0 g, distributed in 32 aquarium (130 L). The physical and chemical water parameters were measured every two weeks. Fish were fed twice a day, in the morning and another at the end of the day. In this trial were used 640 pacu juveniles (24.7 ± 2.0 g) distribuided in 32 aquariums (20 fish/aquarium). Throughout the experimental period, water remained at 26.5 oC and the others limnological parameters (dissolved oxygen, pH, alkalinity, ammonia and conductivity) stayed within normal values for the specie. The experimental trial design was entirely casualized in factorial scheme 2 x 4, evaluating two proceeding of diets (extruded and pelletized) and four 'beta' - glucan levels in diets: 0 (control), 0.1%, 0.2% and 0.3% with four repetitions. In this study,'beta' - glucan levels do not provide significant gains on pacu juveniles performance, but treatment with 0,3% - glucan showed better results of weight gain, weight final and specific growth rate. The administration of glucan in the diet, caused changes in hematological parameters and stress indicators in pacu. The fishes fed with glucan showed greater resistance to infection with A. hidrophila. Thus, treatment with 0,1% of glucan presented a lower cost/kg and shows efficiency in health of pacu juveniles.
Orientador: João Batista Kochenborger Fernandes
Coorientador: Elisabeth Criscuolo Urbinati
Banca: Sérgio Fonseca Zaiden
Banca: Fabiana Pilarski
Mestre
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Rathete, Sello Athlone. "A comparative study on the effects of stress on some aspects of in vitro blood coagulation in two freshwater fish species." Thesis, University of Limpopo, 1993. http://hdl.handle.net/10386/2092.
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Madikiza, Zimkitha Josephine Kimberly. "Population biology and aspects of the socio-spatial organisation of the woodland dormouse Graphiurus Murinus (Desmaret, 1822) in the Great Fish River Reserve, South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/443.
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The population biology and socio-spatial organisation of the woodland dormouse, Graphiurus murinus (Desmarest, 1822), was investigated in a riverine forest at the Great Fish River Reserve (GFRR), South Africa. Data were collected by means of a monthly live trapping and nestbox monitoring programme. Between February 2006 and June 2007, 75 woodland dormice were trapped and/or found in nestboxes and marked: these were 39 adults (13 males, 21 females, five undetermined) and 36 juveniles (five males, 14 females, 17 undetermined). The population showed a steady increase from June 2006–November 2006 and a peak in December 2006–January 2007 as a result of the influx of juveniles. The minimum number of dormice known to be alive (MNA) varied between 40 in December 2006– January 2007 (summer), and a low of three in June 2007 (winter). The range in population density was therefore between 1.2 and 16 dormice per ha. Winter mortality and/or spring dispersal accounted for the disappearance of 55 percent of juveniles. The overall annual adult:juvenile ratio was 1.08. The overall sex ratio was 1.94 female per one male. In females, reproductive activity was observed from September 2006 to end January 2007. The pattern observed in males was similar, as dormice with descended testes were exclusively found from October to end January. Females gave birth during the second half of October to beginning of February. Litters (n = 11) consisted of an average (± SD) 3.73 ± 0.47 young. Over the study period, 27 dormice were trapped or found in nestboxes more than eight times, thus allowing me to estimate their home range size and the spatial overlap between these individuals. On average, dormouse home range size was 2,514 m2 (range: 319 – 4,863 m2). No difference was recorded between one-year old adults and older adults, or between all adults and juveniles. However, adult male dormice (3,989 m2, n = 5) had home ranges almost twice as large as females (2,091 m2, n = 9). No similar trend was found in juveniles. Intrasexual home range overlap was on average 62 percent in adult males, and 26 percent in adult females. However, females overlapped with more neighbouring female home ranges than did males with neighbouring male home ranges, so that, as for males, only small parts of female home ranges were really exclusive. On average, males overlapped a larger Abstract Ecology of woodland dormice M.Sc. Thesis 16 proportion (48 percent) of female home ranges than did females with neighbouring male home ranges (27 percent). In addition, males overlapped with significantly more female home ranges (7.8) than did females with male home ranges (4.9). Trapping success and nestbox data agree with the socio-ecological model. Females showed increased mobility during summer, more likely to find suitable nesting sites, and food for milk production during the reproductive season. The use of nestboxes, however, was constant throughout the year. In males, both the trapping success and nestbox use were higher during the mating season (spring), when an increased mobility and occupation of nestboxes probably increased the chances to locate and mate with (a) receptive female(s). Hence, food and (artificial) nest sites may constitute an important resource for females, whereas females seem to represent the main resource for males. Although food availability was not determined, a comparison of female and male distribution patterns provided interesting information on the mating system of woodland dormice. In GFRR, the dispersion pattern of female woodland dormice was “rather” clumped, i.e. females were non-territorial. As some females showed a dyadic intrasexual overlap of up to 90 percent, and population density was very high at the study site, this may indicate that food was very abundant and/or renewed rapidly. Based on the wide range of birth dates observed during the study period, females clearly come into oestrus at different times. In such circumstances (asynchronous sexual receptivity in females), the Female in Space and Time Hypothesis (Ims 1987a) predicts that males will be non-territorial and promiscuous. Live-trapping, nestbox use and home range data indeed suggested that male woodland dormice do not defend territories, but search for and aggregate around receptive females during the mating season.
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Delbon, Marina Carvalho [UNESP]. "Ação da benzocaína e do óleo de cravo sobre parâmetros fisiológicos de tilápia, Oreochromis niloticus." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/86712.
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Universidade Estadual Paulista (UNESP)
Avaliou-se as concentrações ideais e os tempos de indução e de recuperação do anestésico benzocaína e óleo de cravo, em juvenis de Oreochromis niloticus. Para isso, testou-se cinco concentrações de óleo de cravo e três de benzocaína e, com as análises de freqüência cardíaca, determinou-se que 100 mg/L de benzocaína e 80 mg/L de óleo de cravo foram as concentrações mais eficazes para estes organismos-teste. A partir destas determinações, montou-se um experimento onde foram analisadas alterações fisiológicas (cortisol, glicose, hematócrito, hemoglobina, número total de células sangüíneas, VCM, HCM, CHCM, contagem total de trombócitos e contagem total e diferencial de leucócitos), a 23ºC e a 28ºC, e o tempo que os peixes levaram para se alimentar após o tratamento anestésico. Com estas análises, concluiu-se que os anestésicos testados minimizaram o efeito do estresse causado por manipulações e procedimentos invasivos, e que os peixes submetidos ao tratamento com óleo de cravo, apesar de não ser significativo, apresentaram maiores taxas de alimentação, em relação aos demais tratamentos.
The ideal concentrations, induction and recovery time after treatment with benzocaine anaesthetic and clove oil, in juvenile of Oreochromis niloticus has been evaluated. Five concentrations of clove oil and three of benzocaine were tested. Through the analyses of cardiac frequency, it was show that 100 mg/L of benzocaine and 80 mg/L of clove oil showed the most efficient concentrations for this test organism. Further, an experiment where physiological alterations (cortisol, glucose, hematocrit, hemoglobin, total number of cells, MCV, MCH, MCHC, total counting of trombocytes and total and differential countings of leukocytes), at 23ºC and 28ºC was conducted, as well as the time that the fish fed after anaesthetic treatment. It was concluded that the tested anaesthetics minimized the stress effects caused by manipulations and invasive procedures, and that the fish submitted to the treatment with clove oil, although not significant, presented higher feeding rates, in relation to the other treatments.
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Pereira, Maria Angélica dos Reis Garrido. "Uso do probiótico Bacillus spp. na larvicultura do bijupirá Rachycentron canadum em sistema de recirculação de água." reponame:Repositório Institucional da FURG, 2011. http://repositorio.furg.br/handle/1/2572.
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O bijupirá (Rachycentron canadum) é um peixe marinho que apresenta bom potencial para seu cultivo. Muitas pesquisas demonstram os efeitos benéficos do probiótico Bacillus spp. na aquicultura, porém não há estudos sobre os efeitos de probióticos em sistemas de recirculação de água (SRA). Este trabalho analisa os efeitos do probiótico Bacillus spp. na performance de larvas de bijupirá criadas em SRA. O experimento foi realizado na Universidade Virginia Tech (EUA). As larvas foram estocadas em dois SRA independentes entre si - tratamento probiótico (TP) e tratamento controle (TC) - na densidade de 15 larvas/L, durante 26 dias após a eclosão. Um dos sistemas (TP) recebeu a adição de probiótico comercial composto por B. subtilis, B. licheniformis e B. pumilus diretamente na água e via alimento vivo, conforme o fabricante. As análises de microbiologia e qualidade de água foram feitas diariamente por medição de parâmetros físico e químicos e plaqueamento em meio de cultura para contagem de Bacillus totais e Vibrio totais. Ao final do experimento foram realizados biometria e contagem total dos animais, teste de resistência ao estresse salino e fixação de larvas para imunohistoquímica do timo para avaliar a expressão dos complexos multirreceptores de antígenos CD3 e CD4 de linfócitos T e morfometria do rim cefálico. A sobrevivência foi similar e de 14,9±2,4% e 15,1±0,9% para TP e TC respectivamente. O peso final foi de 170±10 mg para TP e 160±10 mg TC, não havendo diferença estatística entre os tratamentos. Na microbiologia da água não foram encontradas diferenças significativas entre os tratamentos na contagem de víbrios totais (TP: 3.366±522 UFC/mL; TC: 4.964±902 UFC/mL). Na contagem de Bacillus totais os tratamentos diferiram estatisticamente, sendo maior a concentração no TP pela adição dos Bacillus spp. (901±88 UFC/mL e 61±24 UFC/mL). O teste de estresse por salinidade demonstrou uma maior resistência ao estresse salino pelas larvas do tratamento probiótico. A análise imunohistoquímica mostrou uma maior expressão de CD4 no timo em PT (TP: 43,7 ± 6,16% CD4 células/mm²; TC: 25,4 ± 3,5% CD4 células/mm²), o que pode indicar uma melhor resposta imune contra patógenos. A análise morfométrica do rim cefálico indica que este órgão é maior no TP (TP: 0,97 ± 0,33 milímetros; TC: 0,69 ± 0,22 milímetros), provavelmente devido a um aumento na quantidade de linfócitos B. Estes resultados indicam que o probiótico utilizado em um sistema de recirculação de água é efetivo quanto à imunoestimulação e aumenta a resistência ao estresse salino.
Cobia (Rachycentron canadum) is a marine finfish with good potential for mariculture. The aim of this study was to analyze the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS). Many studies have demonstrated the beneficial effects of probiotic Bacillus spp. in aquaculture, but there are no studies on the effects of probiotics in RAS, requiring research on their effectiveness, since in open systems the beneficial effects are already known. The trial was conducted at Virginia Tech VSAREC (USA). Larvae were stocked into two independent RAS - probiotic treatment and control - at a density of 15 larvae L-1, for 26 days after hatching. One of the systems (Probiotic treatment) received the addition of a commercial probiotic consisting of Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus directly into the water and by live feed, according to the manufacturer. At the end of the experiment we performed biometrics, larvae counts, stress test and larvae were fixed for morphometric analysis of head kidney and for immunohistochemistry of thymus to evaluate the phenotypic expression of complex antigens CD3 and CD4 in T-lymphocytes. Survival and final weight had no significant difference between groups. The analysis of water microbiology had no significant differences between treatments in total counts of Vibrio, but in the total count of Bacillus treatments differed statistically, with a higher concentration in Probiotic treatment because of the addition of Bacillus spp. in this group. The salinity stress test was expressed by stress sensitivity index (SSI), which demonstrated a greater resistance to salt stress by larvae of probiotic treatment. Immunohistochemical analysis showed a higher expression of CD4 in Probiotic treatment, which may indicate better immune response against pathogens. The morphometric analysis of head kidney indicates that this organ is larger in Probiotic treatment, probably due to an increase in the quantity of B-lymphocytes. These results indicate that Bacillus spp. probiotics used in RAS may stimulate the immune system and increase the general stress resistance of cobia larvae.
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Seco, Ana Margarida Maurício. "Abate de corvina (Argyrossomus regius) : qual o método que minimiza o stress e maximiza a qualidade?" Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2019. http://hdl.handle.net/10400.5/19258.
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Dissertação de Mestrago Integrado em Medicina VeterináriaA etapa do abate é um dos pontos críticos na gestão da piscicultura, ao induzir stress nos peixes, o que não só afeta o bem-estar animal, como também a qualidade do produto final. No decorrer das investigações relativas à neuroanatomia e neurofisiologia dos peixes, é cada vez mais aceite que, tal como os mamíferos e aves, os peixes também são animais sencientes. Contudo, não são abrangidos pelo regulamento relativo à proteção dos animais no abate. Como tal, a etapa do abate de peixes acaba por ser negligenciada, ao ter pouca ou nenhuma consideração pelo bem-estar animal. O principal objetivo desta dissertação é dar uma visão integrada dos efeitos de diferentes métodos de atordoamento e abate na corvina (Argyrosomus regius), um peixe teleósteo da família Sciaenidae, com crescente utilização na aquacultura. Os métodos estudados foram asfixia por exposição ao ar, termonarcose, eletronarcose, secção medular e iki jime. Foi avaliada a influência destes métodos nas componentes bem-estar animal e qualidade. No que se refere ao bem-estar animal, procedeu-se à avaliação da insensibilização e da resposta fisiológica ao stress, quanto à qualidade foi avaliada a evolução do músculo post mortem (rigor mortis) em associação com a avaliação sensorial do grau frescura. Os resultados revelaram que, o método japonês iki jime foi o único a induzir insensibilização imediata que, por sua vez, apresentou a resposta ao stress mais discreta e melhores resultados em termos de qualidade. Também foi possível apoiar a tese de que a asfixia por exposição ao ar não é uma prática ética, ao induzir uma resposta ao stress grave, o que demonstrou afetar de forma negativa a qualidade, ao acelerar o desenvolvimento do rigor mortis e, por sua vez, a deterioração do músculo. Como complementaridade ao estudo anterior, foi realizado um inquérito por questionário, com o objetivo de avaliar a perceção do consumidor sobre o abate de peixes. Os resultados revelaram que, existe um forte desconhecimento acerca deste domínio, sobretudo no que se refere aos métodos de atordoamento e abate alternativos ao método praticado na pesca tradicional (asfixia por exposição ao ar). Contudo, os resultados revelaram também que, o método de abate a que o peixe for submetido pode influenciar a atitude do cidadão enquanto consumidor, o que pode representar um impacto no mercado. O reforço desta preocupação com o bem-estar dos peixes no abate, para além de promover a adoção de práticas mais éticas, também contribui para melhorar a qualidade, e assim, satisfazer as necessidades das caraterísticas intrínseca e extrínsecas do produto, exigidas por parte do consumidor.
ABSTRACT - Slaughter of meagre (Argyrosomus regius): what is the method that minimizes stress and maximizes quality? The slaughter is one of the important steps in fish farming management, it causes stress on animals and consequently reduces animal welfare as well as the quality of the product. In the course of investigations into the neuroanatomy and neurophysiology of fish, it is becoming more accepted, that like mammals and birds, fish are also sentient animals. However, they are not embraced by animal rights regulations. Therefore, the stage of fish slaughter ends up being neglected, with no consideration for the animal welfare. The main objective of this dissertation is to provide an evaluation of the effects of different stunning and slaughter methods in meagre (Argyrosomus regius), a teleost fish of the Sciaenidae family, with increasing exploration in aquaculture. The methods studied were: asphyxiation by air exposure, thermonarcosis, electronarcosis, medullary section and iki jime. The influence of these methods on animal welfare and quality components was evaluated. With regard to animal welfare, the sensitization and physiological response to stress were evaluated. The quality of the post mortem muscle (rigor mortis) evolution was evaluated in association with the sensory evaluation of the freshness degree. The results showed that the Japanese, iki jime, method was the only one that induced immediate insensitivity, which in turn had a lower stress response and better quality. It was also possible to concluded that asphyxiation by air exposure is not an ethic practice, causing high levels of stress, which negatively affects meat quality by accelerating the process of fish deterioration. As a complement to the previous study, a survey was conducted to assess fish slaughter awareness by fish consumers. The results revealed that fish slaughter is still a fairly unknown subject, especially regarding the alternative methods to the traditional method (asphyxiation by air exposure). However, it revealed that consumers preference can be influence, when they are aware of the different slaughter methods, which can have an impact on the market. Using slaughter methods that take animal welfare in account, will not only reduce the animal stress but also improve fish quality, and thus meeting the needs of the intrinsic and extrinsic characteristics of the product by the consumer.
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Miralles, Pérez Bernat. "Effects of Fish Oil and its Combination with Grape Seed Polyphenols or Buckwheat D-Fagomine on Cardiometabolic Risk Factors and Oxidative Stress in Rats." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672213.
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En les darreres dècades, les prevalences d’obesitat, de dislipèmia aterogènica i de síndrome metabòlica han augmentat considerablement a nivell mundial. La resistència a la insulina és una característica comuna en aquests trastorns cardiometabòlics. La patogènesi de la resistència a la insulina està clarament relacionada amb l’estrès oxidatiu, la inflamació i l’acumulació de lípids bioactius com els diacilglicerols i les ceramides. Els àcids grassos poliinsaturats ω-3 (AGPI ω-3) presents en l’oli de peix, l’àcid eicosapentaenoic (EPA) i l’àcid docosahexaenoic (DHA), s’associen a un menor risc de desenvolupar trastorns cardiometabòlics. No obstant això, quan es proporciona en excés, el DHA pot provocar efectes perjudicials sobre la salut. La combinació de compostos bioactius pot ser una estratègia preventiva per protegir contra l’aparició de trastorns cardiometabòlics. L’objectiu d’aquest treball és avaluar l’efecte de l’oli de peix i la seva combinació amb els polifenols de llavors de raïm o la D-fagomina del blat sarraí sobre els factors de risc cardiometabòlics i l’estrès oxidatiu en rates sanes i en rates alimentades amb una dieta rica en greixos. La suplementació amb l’oli de peix ric en DHA millora diversos factors de risc cardiometabòlics, però augmenta el dany oxidatiu a biomolècules en rates sanes. La suplementació combinada amb l’oli de peix amb una proporció de EPA/DHA 1:1 i els polifenols de llavors de raïm tendeix a atenuar l’estrès oxidatiu, i afecta significativament el contingut de lípids bioactius al fetge de rates alimentades amb una dieta rica en greixos. La suplementació combinada amb l’oli de peix amb una proporció de EPA/DHA 1:1 i la D-fagomina de blat sarraí exerceix efectes beneficiosos sobre l’estrès oxidatiu i sobre alguns factors de risc cardiometabòlics en rates alimentades amb una dieta rica en greixos. Augmentar la ingesta dietètica d’AGPI ω-3 mitjançant suplements d’oli de peix amb una proporció de EPA/DHA 1:1, de forma individual o combinada amb els polifenols o la D-fagomina, pot ser una estratègia nutricional útil per protegir contra els mecanismes implicats en l’aparició de trastorns cardiometabòlics en individus sans i en individus amb un alt risc de malaltia.En las últimas décadas, las prevalencias de obesidad, de dislipidemia aterogénica y de síndrome metabólico han aumentado a nivel mundial. La resistencia a la insulina es una característica común en estos trastornos cardiometabólicos. La patogenia de la resistencia a la insulina está claramente relacionada con el estrés oxidativo, la inflamación y la acumulación de lípidos bioactivos como los diacilgliceroles y las ceramidas. Los ácidos grasos poliinsaturados ω-3 (AGPI ω-3) presentes en el aceite de pescado, el ácido eicosapentaenoico (EPA) y el ácido docosahexaenoico (DHA), están asociados a un menor riesgo de desarrollar trastornos cardiometabólicos. Sin embargo, cuando se administra en dosis excesivas, el DHA puede provocar efectos perjudiciales para la salud. La combinación de compuestos bioactivos puede ser una estrategia preventiva para proteger contra la aparición de trastornos cardiometabólicos. El objetivo de este trabajo es evaluar los efectos del aceite de pescado y su combinación con polifenoles de semillas de uva o D-fagomina del trigo sarraceno sobre los factores de riesgo cardiometabólico y el estrés oxidativo en ratas sanas y en ratas alimentadas con una dieta rica en grasas. La suplementación con el aceite de pescado rico en DHA mejora varios factores de riesgo cardiometabólico, pero aumenta el daño oxidativo de las biomoléculas en ratas sanas. La suplementación combinada con el aceite de pescado con una proporción EPA/DHA 1:1 y los polifenoles de semillas de uva tiende a reducir el estrés oxidativo y modula significativamente el contenido de lípidos bioactivos en el hígado de ratas alimentadas con una dieta alta en grasas. La suplementación combinada con el aceite de pescado con una proporción EPA/DHA 1:1 y la D-fagomina del trigo sarraceno tiene efectos beneficiosos sobre el estrés oxidativo y sobre algunos factores de riesgo cardiometabólico en ratas alimentadas con una dieta rica en grasas. Aumentar la ingesta dietética de AGPI ω-3 mediante suplementos de aceite de pescado con una proporción EPA/DHA 1:1, de forma individual o combinada con los polifenoles o la D-fagomina, puede ser una estrategia nutricional útil para proteger contra los mecanismos implicados en el desarrollo de trastornos cardiometabólicos en individuos sanos y en individuos con un alto riesgo de enfermedad.
The past few decades have seen an alarming increase in the worldwide prevalence of obesity, atherogenic dyslipidemia, and metabolic syndrome. Insulin resistance is a common characteristic in these cardiometabolic disorders. The pathogenesis of insulin resistance is clearly related to oxidative stress, inflammation as well as accumulation of bioactive lipids such as diacylglycerols and ceramides. The ω-3 polyunsaturated fatty acids (ω-3 PUFA) from fish oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with lower risk for developing cardiometabolic disorders. Nevertheless, when provided in excess, DHA may lead to deleterious effects on health. Combining bioactive compounds may be a powerful preventive strategy to protect against the onset of cardiometabolic disorders. The aim of the present work is to explore the influence of fish oil and its combination with grape seed polyphenols or buckwheat D-fagomine on cardiometabolic risk factors and oxidative stress in healthy rats and in rats fed a high fat diet. The supplementation with the fish oil rich in DHA beneficially affects several cardiometabolic risk factors, but increases oxidative damage to biomolecules in healthy rats. The combined supplementation with fish oil containing EPA/DHA 1:1 and grape seed polyphenols tends to attenuate oxidative stress, and significantly modulates abundances of bioactive lipids in the liver of rats fed a high fat diet. The combined supplementation with fish oil containing EPA/DHA 1:1 and buckwheat D-fagomine exerts beneficial influence on oxidative stress and on some related cardiometabolic risk factors in rats fed a high fat diet. The increase in dietary intake of ω-3 PUFA from fish oil supplements containing EPA/DHA 1:1, alone or combined with polyphenols or D-fagomine, may be a useful nutritional strategy to protect against the mechanisms underlying the onset of cardiometabolic disorders in healthy individuals and in individuals at high risk of disease.
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Volkova, Kristina. "Fishy behavior : persistent effects of early-life exposure to 17α-ethinylestradiol." Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-45505.
Full textAbstract:
The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.