Thèses : « Carcinus »

1

Relf, Juliet M. « Antibacterial proteins in 'Carcinus maenas' (Crustacea:Decapoda) ». Thesis, University of St Andrews, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553712.

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Al-Hadi, T. A. A. « Osmoregulation in the crab Carcinus maenas ». Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374249.

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3

Hazel, C. M. « Steroidogenesis in the female crab (Carcinus maenas) ». Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372692.

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4

Burch, Alexandra. « The foraging behaviour of shallow water crabs ». Thesis, Bangor University, 1998. https://research.bangor.ac.uk/portal/en/theses/the-foraging-behaviour-of-shallow-water-crabs(0e293f58-80a5-466f-8d3a-90ac3c384b4c).html.

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This is a study of the foraging behaviour of Carcinus maenas on Mytilus edulis and of Thalamita danae on Perna viridis. Particular attention is given to differences arising in foraging behaviour as a result of intraspecific prey heterogeneity and experimental protocol. Intersite and temporal differences in the population density, shell morphology, biomass and byssal attachment strength of Mytilus edulis were found. Byssal attachment strength and shell strength were highly variable amongst individuals of a similar size. Carcinus maenas is strongly heterochelous. Intraspecific differences in the chelal mechanics, but not in the chelal geometry, were recorded; major chelae of large male crabs were significantly stronger than the major chelae of females and small males. Stomach content analyses showed that Carcinus maenas has a broad diet in which Mytilus edulis forms an important component. Intersite differences inMytilus edulis shell morphology altered the foraging behaviour of Carcinus maenas, and intersite and temporal variations in mussel flesh weight altered the prey value curves. Both C. maenas and Thalamita danae were highly prey size-selective when foraging on groups of different sized mussels, the size of prey most vulnerable to predation altering with the size composition of the group. The handling times of mussels for both species of crab were reduced when mussels were presented as part of a group as compared to when mussels were presented singly. For Carcinus maenas the reduced handling times resulted from the less extensive gleaning of mussel shells whilst for Thalamita danae reduced handling times appeared to result from the greater use of a more time efficient opening technique. When Carcinus maenas were presented with mussels of differing attachment strengths, crabs selected more weakly attached mussels over those with a more firm and rigid attachment. This selection did not appear to be based on prey value or prey length but rather on the resulting slight movement of weakly attached mussels whenever these were touched by a foraging crab.

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Fletcher, Nichola. « Behavioural complexities in the European shore crab, Carcinus maenas ». Thesis, University of Hull, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445306.

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6

Murray, Lee Gordon. « The impact of Carcinus Maenas on commercial mussel beds ». Thesis, Bangor University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445100.

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7

Barber, Kathleen Gladys. « Response of the shore crabs Hemigrapsus oregonesis and Hemigrapsus nudus to paralytic shellfish toxins ». Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27797.

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The following research deals with the response of the small shore crabs, Hemigrapsus oreqonesis and Hemigrapsus nudus to paralytic shellfish toxins (PST). These shore crabs were shown to develop a remarkable seasonal resistance to administered saxitoxin (STX). No similar change in sensitivity was found after administration of tetrodotoxin (TTX), another marine neurotoxin with similar actions to the PST. Resistance to STX in the small shore crabs was linked to the presence of PST in the viscera, and this in turn was related to the presence of toxic dinoflagellate blooms in the area. Furthermore, this research provides, for the first time, evidence of a protein component (MW 145,000 daltons) which appears to be associated with acquired resistance to PST in the shore crab. In addition, this protein component was shown to appear in sensitive crab extracts after the administration of low doses of saxitoxin and tetrodotoxin in vivo.
Land and Food Systems, Faculty of
Graduate

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Tenório, Kláudia Emanuela Ramos. « Avaliação da estrutura genética do camarão de água doce em extinção, pitu (Macrobrachium carcinus), no Nordeste como ferramenta para apoiar programas de repovoamento ». Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/12331.

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O camarão de água doce Macrobrachium carcinus (LINAEUS, 1758) pode ser encontrado em regiões tropicais e subtropicais. No Brasil, está distribuído desde o Pará até Rio Grande do Sul, em rios que deságuam no oceano Atlântico. Esta espécie tem sofrido com a sobrepesca, a poluição ambiental, a destruição dos ambientes naturais, barramento dos rios e riachos, os quais impedem o acesso ao mar impossibilitando o desenvolvimento dos estágios larvais do animal, além da introdução de espécies exóticas, como o M. rosenbergii. Por essas razões, o Ministério do Meio Ambiente (MMA) inseriu o M. carcinus na lista oficial das espécies ameaçadas de extinção em vários estados do Nordeste. Visando fornecer informações para as iniciativas de repovoamento, este estudo teve como objetivo avaliar a diversidade e estrutura genética, bem como aspectos da ecologia desta espécie em quatro estados do Nordeste (Ceará, Pernambuco, Sergipe/Alagoas e Bahia), utilizando seis marcadores de microssatélites, dados biométricos e análises de conteúdo estomacal. Um total de 143 animais foi coletado, sendo de 32 a 40 animais para cada um dos rios avaliados. Após as análises, o número de alelos variou de dois a 18 alelos, com heterozigosidades médias esperadas e observadas de 0,6256 e 0,5985 respectivamente. Três dos seis loci estão em desequilíbrio de Hardy-Weinberg e apresentam alelos nulos em todas as populações. O valor total de FST foi de 0, indicando ausência de estruturação genética. Os estudos biológicos mostram que o pico reprodutivo mais provável para esta espécie ocorra em fevereiro. A análise estomacal revelou predominância de itens de origem vegetal. Estes resultados sugerem que um único programa de repovoamento poderia fornecer pós-larvas a todos os rios da região Nordeste, diminuindo os custos de operação e garantido que rios distantes de laboratórios de multiplicação também sejam beneficiados.

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9

Zeng, Chaoshu. « Behavioural basis of larval dynamics in the crab Carcinus maenas ». Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296340.

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O'Callaghan, Felicity E. « The effect of temperature on pressure sensing in the crab Carcinus maenas (L.) ». Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=195131.

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Hydrostatic pressure sensing is used by aquatic animals to estimate depth and to synchronize behaviour with the tides. Pressure sensors examined to date depend on the compression of a fluid, making them susceptible to temperature change. Despite this, the effects of temperature on pressure sensing have not so far been researched. This thesis examined the effects of temperature on the afferent firing rate of thread hair pressure receptors in the crab Carcinus maenas. It tested the hypothesis that for sensors responding positively to rising pressure, an increase in temperature should counteract any contraction in volume, thereby leading to a weaker neural response; vice versa, a stronger response was predicted for a temperature decrease. A novel system was developed which allowed the simultaneous application of sinusoidal pressure change from 150 to 350 mbar and cycles of temperature, typically spanning between 16 and 22 °C, while extracellular recordings were made en passant from afferent nerves innervating statocyst thread hairs. Motor programmes were designed to stimulate thread hairs sensitive to clockwise and anticlockwise rotation through continuous or interrupted bouts of oscillation within the horizontal plane. During constant pressure, raising temperature led to increases in spike frequency and amplitude, with Q10s between 3 and 5 for spike frequency but less than 2 for amplitude. Cooling caused the elimination or decrease of pressure responses while increasing them on heating, thereby contradicting the aforementioned hypothesis of temperature mimicking pressure change. Changes in the timing of pressure responses were also observed. In preparations which were non-responsive to pressure change, temperature change led to bursts in firing at the peaks or troughs of pressure cycles in 28 of 42 preparations, with evidence for recruitment of formerly silent units. The results could not be fully explained under the existing model for pressure sensing by thread hairs, highlighting the necessity for further anatomical studies.

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11

Hebel, Dagmar Karina. « Effects of copper on gill structure and physiology in Carcinus maenas ». Thesis, University of Plymouth, 1997. http://hdl.handle.net/10026.1/2296.

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The effects of sublethal copper exposure at three levels of biological organisation were studied in the common shore crab Carcinus maenas (L.) (Crustacea, Decapoda). The three levels included the ultrastructure of respiratory and osmoregulatory gill tissues; ventilatory physiology (scaphognathite activity); and tissue metallothionein levels. Respiratory gill epithelia were more sensitive to sublethal copper exposure than osmoregulatory gill tissues. The cellular damage observed included severe epithelial necrosis and vacuolation, hyperplasia and haemocyte infiltration. In the respiratory gills, these changes were first present following exposure to 100 µg Cu Lˉ¹ At 500 µg Cu Lˉ¹, there was complete degeneration of the epithelia. In osmoregulatory gills, lipofuscin granules were formed at 300 µg Cu Lˉ¹. Signs of cellular damage (as observed in respiratory gills) appeared in the osmoregulatory gills only following exposure to 500 µg Cu Lˉ¹, and were restricted to areas proximal to the marginal canal. Copper concentrations below 100 µg Cu Lˉ¹ had no effect on gill tissues. This result is discussed with reference to previous studies, and related to inter-population differences and exposure techniques. Gill ultrastructural differences were observed in crabs from two estuaries with different levels of water-borne trace metals, and in crabs transplanted from the cleaner to the more polluted site. Differences included . varying densities of plasmalemmal folds and frequencies of cellular vacuolation, as well as composition and thickness of algal surface layers on the gill cuticle. Following laboratory copper exposures (500 µg Cu Lˉ¹), gill ultrastructural "damage" and tissue metallothionein levels were related to changes in scaphognathite activity. Physiological effects, including changes in scaphognathite rate and periods of apnoea, were exacerbated by increased temperature and hypoxia. Changes in scaphognathite activity and metallothionein levels were not consistent following several exposures to the same level of copper; results are discussed in relation to physiological influences. In contrast, gill ultrastructure showed consistent deterioration following exposure to 500 µg Cu Lˉ¹. Gill ultrastructure represents a reliable indicator of exposure to copper at this concentration compared to both scaphognathite activity and metallothionein concentrations.

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Hill, Andrew Douglas. « The anaerobic metabolism of the common shore crab, Carcinus maenas (L.) ». Thesis, University of Glasgow, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363251.

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13

Rorai, Ann Theresa. « Growth and sex pheromones in the shore crab Carcinus maenas (L.) ». Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289181.

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Eiras, Felisa Rey. « Maternal effects and settlement performance of the green crab Carcinus maenas ». Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16453.

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Doutoramento em Ciências do Mar e do Ambiente
The majority of benthic marine invertebrates display complex life cycles characterized by life stages with contrasting features. These organisms commonly exhibit a dispersive pelagic larval form(s) that experiences a dramatic event that shifts its morphology and behaviour – the metamorphosis. This event gives origin to a benthic juvenile stage that may also experience additional changes in its morphology, behaviour and physiology until reaching the adult stage and becoming sexually mature. The path between hatching and settlement is a challenging one that only a minute fraction of individuals overcomes. Unravelling the processes that condition the life history strategies and settlement success of benthic marine invertebrates is essential to understand the shaping of adult populations, as well as ecological and evolutionary pathways. In this regard, the present thesis analyses important stages in the life history of a model benthic marine invertebrate with a complex life cycle: the embryonic development, larval settlement and early benthic performance of the green crab Carcinus maenas. The first part of this thesis analyses maternal effects as a source of variability in offspring quality, using biochemical tools. It explores the hypothetical existence of embryonic variability as a consequence of their positioning within the brooding chamber at oviposition and during embryogenesis. Fatty acid profiles of embryos in early (stage 1) and late (stage 3) stages are used as proxies to analyse maternal provisioning and larval quality at hatching, respectively. Through a lipidomic approach, the embryogenesis of C. maenas and Necora puber, two closely related brachyuran crabs that occur in sympatry in the study site, is compared. Polar lipid dynamics is unravelled for the first time in these ecologically and economically important species. Finally, two different time scales, annual and seasonal, are employed to investigate the existence of temporal variability in offspring quality, with the role that maternal size may play as another source of variability also being investigated. The second part of this thesis focus in the early benthic life of juvenile C. maenas. Wild megalopae collected in Ria de Aveiro are used to understand how the pelagic life experienced by developing larvae before becoming competent (receptive to settlement cues) can condition their early benthic life. Competent larvae are exposed to extreme abiotic and trophic conditions to comprehend how their phenotypic plasticity and potential carry-over effects influence consecutive life stages. The part of the study addressing maternal effects revealed that C. maenas did not present any significant within brood variability in newly extruded (stage 1) and ready to hatch (stage 3) embryos. Therefore, maternal provisioning and the incubation environment within the brooding chamber were homogeneous across the whole brood. Nevertheless, a highresolution lipidomic analysis showed that embryogenesis is a dynamic process, suggesting a specialization of lipid functions along the embryonic development. Moreover, maternal provisioning and incubation environment were not influenced by maternal size. Nonetheless, the lipid composition of the yolk was conditioned by the period in which the ovarian maturation occurred. While the environmental conditions prevailing during the incubation altered the fatty acid profile of the ready to hatch embryos. After experiencing a planktonic life, competent larvae displayed different post-settlement performance, clearly reflecting the pelagic conditions that they have experienced during their larval life. Optimal grow-out conditions did not delete these larval fingerprints, with their consequences being carried-over to early benthic life and conditioning the phenotype of juvenile crabs. Larval life plays such an important role in the life history of benthic marine invertebrates that even exposure during a few days to extreme abiotic and trophic conditions can influence their post-settlement performance. Overall, metamorphosis is definitely not a new beginning for C. maenas. In fact, the early postmetamorphosis performance of this brachyuran crab can be strongly conditioned by trait mediated effects that are carried over from its embryonic and/or pelagic larval life to its benthic juvenile and/or adult stages.
A maioria dos invertebrados bentónicos marinhos apresentam ciclos de vida complexos, com características contrastantes entre os diferentes estádios. Estes organismos normalmente exibem uma forma larval pelágica (ou várias), a qual sofre um evento dramático que muda a sua morfologia e comportamento – a metamorfose. Este evento dá origem ao estádio juvenil, o qual também experimenta mudanças na sua morfologia, comportamento e fisiologia, até atingir o estádio adulto e ser sexualmente maduro. O percurso entre a eclosão e o assentamento é um desafio que só uma pequena fracção de indivíduos consegue superar. Revelar os processos que condicionam as estratégias do ciclo de vida e o êxito no assentamento dos invertebrados bentónicos marinhos é essencial para compreender a dinâmica das populações adultas, assim como a sua trajetória a nível ecológico e evolutivo. Neste sentido, esta tese analisa importantes estádios no ciclo de vida de uma espécie modelo de invertebrados bentónicos marinhos: o desenvolvimento embrionário, o assentamento larval e o desempenho dos primeiros estádios da vida bentónica do caranguejo Carcinus maenas. A primeira parte desta tese analisa os efeitos maternais, como fonte de variabilidade na qualidade da descendência, usando ferramentas bioquímicas. Explora a existência hipotética da variabilidade embrionária, como consequência da posição dos embriões dentro da câmara de incubação no momento da extrusão e durante a embriogênese. O perfil dos ácidos gordos dos embriões, na fase inicial (estádio 1) e fase tardia (estádio 3) da embriogênese, foram usados como estimativa para analisar o investimento maternal e a qualidade das larvas no momento da eclosão, respectivamente. Através de uma abordagem lipidómica, é comparada a embriogênese de C. maenas e Necora puber, dois caranguejos braquiúros estreitamente relacionados que ocorrem em simpatria na área de estudo. A dinâmica dos lípidos polares é revelada pela primeira vez nestas espécies de interesse ecológico e comercial. Para finalizar, duas escalas temporais diferentes, anual e sazonal, são utilizadas para investigar a existência de variabilidade temporal na qualidade da descendência, incluindo o papel do tamanho maternal como outra fonte de variabilidade. A segunda parte da tese foca-se no início da vida bentónica dos juvenis de C. maenas. Megalopas selvagens recolhidas na Ria de Aveiro, são usadas para entender como as experiências da vida pelágica antes de se tornar competentes (recetivas aos sinais de assentamento) podem condicionar a sua vida bentónica. As larvas competentes são submetidas a condições tróficas e abióticas extremas para compreender como a sua plasticidade fenotípica e os potenciais efeitos latentes influenciam as fases subsequentes do ciclo de vida. O estudo dos efeitos maternais revelou que C. maenas não apresenta variabilidade dentro da massa de embriões recém extrudidos (estádio 1), nem nos que estão para eclodir (estádio 3). Portanto, o investimento maternal e as condições durante a incubação foram homogéneas em toda a massa de embriões. No entanto, uma análise de alta resolução mostrou que a embriogênese é um processo dinâmico, sugerindo uma especialização das funções dos lípidos durante o desenvolvimento embrionário. Por outro lado, o investimento maternal e as condições de incubação não foram influenciadas pelo tamanho maternal. Contudo, a composição lipídica dos ovos foi condicionada pelo período no qual a maturação do ovário ocorreu, enquanto as condições ambientais existentes durante a incubação modificaram o perfil de ácidos gordos dos embriões prontos para eclodir. Após a fase planctônica, as larvas competentes exibiram diferentes níveis de rendimento pósassentamento, reflectindo claramente as condições pelágicas experimentadas durante a vida larval. Condições ótimas de crescimento não apagam a pegada da vida larval, sendo transferidas as consequências para o início da vida bentónica e condicionando o fenotipo dos caranguejos juvenis. A vida larval desempenha um papel tão importante na história de vida dos invertebrados bentónicos marinhos que, inclusivamente, a exposição a condições tróficas e abióticas adversas durante poucos dias influenciam o desempenho após o assentamento. Globalmente, a metamorfose não é, definitivamente, um novo começo para C. maenas. Na verdade, o desempenho pós-metamorfose no início da vida bentónica deste caranguejo braquiúra pode ser fortemente condicionada pelos efeitos latentes que são transferidos desde a vida larval pelágica até os estádios bentónicos, juvenil e/ou adulto.

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Schnapp, Denni. « Antiviral defence and antibacterial proteins in the shore crab Carcinus maenas ». Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14852.

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The defence reactions of the shore crab, Carcinus maenas, to a range of viruses were investigated in vivo and in vitro. In vivo studies with injected bacteriophages showed that C. maenas is capable of discriminating between different bacteriophages and actively removes certain phages from the haemocoele. Rapid initial clearance of the coliphage T2 was followed by slower removal and the phage persisted in the circulation for at least two weeks. The phage was sequestered to the hepatopancreas where it persisted for at least 72 h. Haemocyte counts remained unchanged upon injection of T2. With respect to prophenoloxidase activation, of the viruses tested only the Chlorella phage PBCV-1 was found to activate haemolymph prophenoloxidase at concentrations above 107 particles ml-1This indicates that C. maenas may respond to high concentrations of viruses in vitro. However, neutralization assays failed to reveal inactivation of viruses in HLS, plasma, or extracts of the hepatopancreas, gut, gill or heart, although some activity against an insect baculovirus and parainfluenza vims was detected in digestive juice. At least four antibacterial proteins, of ca. 6.5 kDa, 11.6 kDa, 20 kDa or 25 kDa, are present in C. maenas haemocytes. One, a 6.5 kDa peptide with activity against Gram positive and Gram negative bacteria, was purified. The N-terminal 30 amino acids of this peptide share over 60% sequence identity with bovine Bac 7, a mammalian cathelicidin. This 6.5 kDa peptide in C. maenas is the first antimicrobial peptide described from the Crustacea. Because the sequence of the pre-propeptide is as yet unavailable, it is not known whether or not it can be included among the cathelicidins. It has not been established whether or not the C. maenas 6.5 kDa peptide has antiviral activity.

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Bell, Karen Lennox. « Studies on phagocytosis in the shore crab Carcinus maenas (Crustacea, Decapoda) ». Thesis, University of St Andrews, 1994. http://hdl.handle.net/10023/14845.

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Phagocytosis by hyaline cells of the shore crab, Carcinus maenas, was investigated in vitro. In particular, the project examined the role of the prophenoloxidase activating system (proPO) in opsonisation, the metabolic requirements of the cells during phagocytosis and the extent of intracellular bacterial killing. Related work investigated the mechanism and regulation of bacterial killing. Uptake was assessed using monolayers of separated hyaline cells challenged with the bacterium, Psychrobacter iminobilis. The bacteria were pretreated with haemocyte lysate supernatant (HLS) to enhance uptake. The opsonic factor(s) were found to be freeze stable and to be generated during serine protease activation of the proPO system. Phagocytosis was also found to depend upon electron transfer and oxidative phosphorylation and to require an intact cytoskeleton for engulfment. Following ingestion, ca 84% of the bacteria were found to be killed within 3h. Experiments designed to investigate the mechanism of killing showed that treatment of the hyaline cells with phorbol 12-myristate 13-acetate, lipopolysaccharide, phytohaemagglutinin or concanavalin A, but not laminarin, sdmulates the production of superoxide ions (O2-). The semi-granular and granular cells did not produce O2- following stimulation. Incubation of the cells with superoxide dismutase (SOD) confirmed that O2- was produced. Parallel experiments were conducted on a range of marine invertebrates. In all cases O2- production was observed, showing that O2- production is a general phenomenon for invertebrate phagocytes. However, quantification of hydrogen peroxide (H2O2) production, using a H2O2 assay, showed that crab phagocytes produced more H2O2 than tunicate phagocytes indicating that the kinetics of the response varies between species. Using immunocytochemistry, the antioxidant enzymes, catalase, glutathione peroxidase and SOD were found to be located within the haemocytes and plasma of C. maenas. These enzymes may minimise the risk of damage to the host tissues by the O2- and H2O2 produced by the hyaline cells.

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Mcgaw, Iain James. « Behavioural responses of the shore crab Carcinus maenus to salinity variation ». Thesis, Bangor University, 1991. https://research.bangor.ac.uk/portal/en/theses/behavioural-responses-of-the-shore-crab-carcinus-maenus-to-salinity-variation(b75f6f70-c663-4702-a955-0eb37bb01e25).html.

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Behavioural responses of the colour forms of Carcinus maenas to salinity variation were investigated, and related to their physiology and distribution in an estuary. Red males, characterised by a thicker carapace were unable to survive in as low salinities as green males; this was reflected in their poorer osmoregulatory capabilities. Haemolymph osmolality and ion concentrations of red crabs decreased at a faster rate and reached lower levels than in green crabs. Haemolymph osmolality and choice behaviour did not vary with size. In the tidally mixed estuary male and female crabs occurred in roughly similar proportions. Most were green and generally smaller than their open shore counterparts. Migration out of the estuary in winter was reversed in late spring. Differences in salinity tolerance of red and green crabs were reflected in salinity preference behaviour. Green crabs persisted longer in the lowest range of salinities tested, especially if a shelter was available. Prior acclimation affected the timing of choice behaviour; the lower the salinity of acclimation the faster the time of exit from the lowest range of salinities tested, and vice versa. Estuarine green crabs exhibited endogenous locomotor activity of circatidal periodicity and were less responsive to episodes of low salinity than open shore red and green crabs. Constant low salinity initiated a rhythm of circatidal periodicity in arhythmic red and green crabs; red crabs reacted faster and were more active upon salinity change than green crabs. The amount of locomotor activity induced after prior acclimation was similar within each acclimation salinity tested. Carcinus detected salinity variation by responding to the concentrations of Na and Cl in seawater, and was able to differentiate between salinities separated by as little as 0.5ppt., - General physiological changes appear to occur before behavioural responses are mediated; they probably act as cues for the behavioural responses, which appear not to be triggered by specific receptors. Behavioural and physiological responses combing to enhance, the survivability of crabs in changing salinities.

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TENÓRIO, Kláudia Emanuela Ramos. « Avaliação da estrutura genética do camarão de água doce em extinção, pitu (Macrobrachium carcinus), no Nordeste como ferramenta para apoiar programas de repovoamento ». Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/18514.

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O camarão de água doce Macrobrachium carcinus (LINAEUS, 1758) pode ser encontrado em regiões tropicais e subtropicais. No Brasil, está distribuído desde o Pará até Rio Grande do Sul, em rios que deságuam no oceano Atlântico. Esta espécie tem sofrido com a sobrepesca, a poluição ambiental, a destruição dos ambientes naturais, barramento dos rios e riachos, os quais impedem o acesso ao mar impossibilitando o desenvolvimento dos estágios larvais do animal, além da introdução de espécies exóticas, como o M. rosenbergii. Por essas razões, o Ministério do Meio Ambiente (MMA) inseriu o M. carcinus na lista oficial das espécies ameaçadas de extinção em vários estados do Nordeste. Visando fornecer informações para as iniciativas de repovoamento, este estudo teve como objetivo avaliar a diversidade e estrutura genética, bem como aspectos da ecologia desta espécie em quatro estados do Nordeste (Ceará, Pernambuco, Sergipe/Alagoas e Bahia), utilizando seis marcadores de microssatélites, dados biométricos e análises de conteúdo estomacal. Um total de 143 animais foi coletado, sendo de 32 a 40 animais para cada um dos rios avaliados. Após as análises, o número de alelos variou de dois a 18 alelos, com heterozigosidades médias esperadas e observadas de 0,6256 e 0,5985 respectivamente. Três dos seis loci estão em desequilíbrio de Hardy-Weinberg e apresentam alelos nulos em todas as populações. O valor total de FST foi de 0, indicando ausência de estruturação genética. Os estudos biológicos mostram que o pico reprodutivo mais provável para esta espécie ocorra em fevereiro. A análise estomacal revelou predominância de itens de origem vegetal. Estes resultados sugerem que um único programa de repovoamento poderia fornecer pós-larvas a todos os rios da região Nordeste, diminuindo os custos de operação e garantido que rios distantes de laboratórios de multiplicação também sejam beneficiados.
The Macrobrachium carcinus (LINAEUS, 1758) can be found in tropical and subtropical regions. In Brazil, it is distributed from Pará to the Rio Grande do Sul, in rivers that empty into the Atlantic Ocean. This specie has suffered with overfishing, pollution, destruction of natural environments, rivers and streams dams that block the access to the sea, what inhibits the development of larval stages of the animal, and the introduction of exotic species such as M. rosenbergii. Because these reasons, the Brazilian Ministry of Environment (MMA) has inserted the M. carcinus in the official list of endangered species in several Northeastern states like Piauí, Cear, Pernambuco, Alagoas, Sergipe and Bahia. In order to provide information to restocking initiatives, the aim of this study was to assess the genetic diversity and structure, as well as aspects of ecology of this species in four regions of the Brazilian Northeast (Ceará, Pernambuco, Sergipe/Alagoas and Bahia), by the use of six microsatellite markers, biometric data and stomach content analysis. A total of 143 animals was collected, with 32-40 animals for each of the rivers evaluated. After the analyses, the number of alleles ranged from two to 18 alleles, with expected average heterozygosities from 0,6256 and observed average heterozygosities from 0,5985. Three of the six loci are in Hardy-Weinberg disequilibrium and present null alleles in all populations. The total value of FST was 0, what indicates no genetic structuration. Biological studies show that reproductive peak for this species most likely to occur in February. The stomach analysis revealed predominance of plant items.These results suggest that a single restocking program could provide post-larvae to all rivers of Brazilian Northeast, which reduce operating costs and ensure the benefit of the rivers that are distant from multiplication laboratories also.

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Marques, Junior Julio. « Aspectos estruturais do hepatopâncreas do camarão de água doce Macrobracium amazonicum (Heller, 1862) / ». Jaboticabal : [s.n.], 2006. http://hdl.handle.net/11449/86707.

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Orientador: Irene Bastos Franceschini Vicentini
Banca: Maíra Aparecida Stefanini
Banca: Maria Terezinha Siqueira Bombonato
Resumo: O hepatopâncreas está associado ao intestino médio e apresenta diferentes níveis de complexidade dentre as espécies de decápodas. O objetivo deste estudo foi descrever a estrutura histológica do hepatopâncreas de Macrobrachium amazonicum descrevendo características macroscópicas e microscópicas, tais como os tipos celulares que o compõe e a organização de seus túbulos secretores. Adultos de ambos os sexos de M. amazonicum foram coletados, e o hepatopâncreas foi estudado usando-se técnicas histológicas. O hepatopâncreas é um órgão de coloração amarelo-acastanhada, organizado em dois lobos laterais. A estrutura é formada por uma massa de túbulos de fundo cego com espaço intertubular escasso. Cada túbulo secreto r consiste de um epitélio circundado por lâmina basal e células mioepiteliais. Cinco tipos celulares foram observados: célula E (indiferenciada), célula F (fibrilar), célula R (reabsortiva), célula B (vesicular) e célula M (basal). As células E foram observadas na porção distal dos túbulos e são responsáveis pela reposição mitótica das células do epitélio. As células F foram observadas principalmente próximas às células E na região distal. Células R foram observadas ao longo de todo o túbulo secretor, principalmente nas regiões proximal e medial. As células B são abundantes nas regiões medial e distal do túbulo, diminuindo sua freqüência na região proximal. Foram observadas células M ao longo de todo o túbulo secretor, associadas às células R.
Abstract: The aim of this study is to describe the histological structure of the hepatopancreas of Macrobrachium amazonicum, describing macroscopic and microscopic characteristics: cellular types and the organizations of the secretory tubules. Adults of both sexes of M. amazonicum were collected and the hepatopancreas was studied by using histological techniques. The hepatopancreas is a bilaterally bilobed brown-yellowish organ. The structure is formed by a mass of blind tubules, with scarce intertubular space. Each tubule consist of a cylindrical epithelial layers surrounded by a basal lamina and myoepithelial cells. Five cellular types were recognized: E-cells (embryonic), E-¬cells (fibrilar), B-cells (blisterlike), R-cells (resorptive) and M-cells (midget). F-¬cells were observed in the distal end of the secretory tubules and are the mitotic cells that replenish the cells of the epithelium. The F-cells were observed along all the tubule, mainly in the distal region next the E-cells. R-cells were observed in the proximal and medial regions. The B-cells were abundant in the medial and distal regions of the tubule. M-cells were observed along all the tubule associated to the R-cells.
Mestre

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Meisingset, Kristine Kiplesund. « Influence of Offshore Wind Farm on Shore Crab Carcinus maenas Population Dynamics ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-21426.

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Many governments have initiated programs of energy production from renewable sources in response to climate changes induced by gases from burning fossil fuels. Use of wind energy is considered a sustainable way of reducing the carbon emission, and offshore wind power generation capacity is expected to grow significantly as the world is trying to make a transition to a lower carbon economy. Though the advantages of renewable energy on a global scale are not in doubt, the effects on the local environment must also be carefully considered. The aim of this study was to investigate the influence of offshore windfarm on shore crab (Carcinus maenas) population dynamics. Data were collected in the Öresund strait in Southern Sweden at Lillgrund offshore windfarm and in to adjacent control areas, Sjollen and Bredgrund. The mark-recapture method was applied to make population size estimation, and the catch per unit effort index was calculated as a measure of abundance. Data on catch per unit effort were also calculated for 8 previous years with data collected from earlier studies in the areas. In addition, size, sex ratio, condition and color were recorded. Due to few recaptures, reliable population size estimations could not be achieved. The population of shore crab within the windfarm was found to be significantly more abundant than those in the control areas in 2012. However, analysis of catch per unit effort in a long term perspective of 10 years, show no effect of the offshore windfarm on shore crab abundance. There was not found any effect of the presence of wind farm on shore crabs regarding size, sex ratio, condition or color.

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Qari, Suhaila. « Adaptive responses to temperature and photoperiod in neuromuscular transmissionin carcinus maenas (l) ». Thesis, Durham University, 2004. http://etheses.dur.ac.uk/3024/.

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Neuromuscular synaptic transmission in the ectothermal crab Carcinus maenas was used to assess the extent to which photoperiod affected the attainment of temperature acclimation. A separate series of experiments were carried out to determine thermotolerance to high temperature (CTMax) and its dependence on prior heat shock and heat shock proteins. Dactylopodite closer muscle resting potentials and the characteristics of evoked excitatory junction potentials in response to stimulation of the excitatory tonic axon were recorded with intracellular microelectrodes and the extent of acclimation to temperature under different photoperiodic regimes was measured. Animals were acclimated for at least two week to either 8 C or 25 C with short day (8hr: 16hr, L/D) or long day (16hr: 8hr, L/D) photoperiods. Photoperiod differences had a marked effect on acclimation to temperature as measured by muscle resting potential and excitatory junction potential amplitude and facilitation. In short day photoperiods there was an acclimatory shift of muscle resting potential in crabs acclimated to 25 C compared with those acclimated to 8 C. Such an acclimatory shift of muscle resting potential was not seen in animals from long day photoperiods. By contrast facilitation showed acclimatory changes to temperature in long day but not in short day photoperiods. Excitatory junction potential amplitudes were increased in cold acclimation; this increase was larger from long day acclimated groups compared with short day groups. Furthermore photoperiod had a large effect on closer muscle tension in animals acclimated at low temperatures but little effect on animals acclimated at high temperatures. Heat shock reduced the amplitude of EJPs recorded in the closer muscle but enabled the EJP to be maintained for much higher temperatures. Heat shock also resulted in an increase in thermotolerance as measured by an elevation of CTMax from 33.04 C to 34.17 C.

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Bublitz, Ralf. « Female sex pheromone in the shore crab Carcinus maenas (Crustacea : Decapoda : Brachyura) ». Thesis, University of Hull, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.478948.

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Keppeler, Erlei Cassiano. « Características limnológicas da água, sedimento e efluentes em viveiros de crescimento final do camarão-da-amazônia, Macrobrachium amazonicum, submetidos a diferentes níveis de arraçoamento e tipos de despescas / ». Jaboticabal, 2005. http://hdl.handle.net/11449/144160.

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Orientador: Wagner Cotroni Valenti
Banca: Odete Rocha
Banca: Antonio Fernando Monteiro Camargo
Banca: Gisela Yuka Shimizu
Banca: Raoul Henry
Resumo: Os viveiros de cultivo semi-intensivo de camarões de água doce são ecossistemas límnicos em fase inicial de sucessão ecológica. Neste trabalho, foi realizado um estudo limnológico de viveiros de cultivo de Macrobrachium amazonicum submetidos a diferentes taxas de arraçoamento e tipos de despescas, visando fornecer subsídios para o entendimento desses ecossistemas e o estabelecimento de um manejo adequado. Doze viveiros com cerca de 0,01 ha foram povoados com 20 juvenis de M. amazonicum.m-2. Os animais foram alimentados com ração extrusada na proporção de 6 a 9% da biomassa até a 14. a semana. Então, os camarões contidos em cada três viveiros foram arraçoados com 3%, 5% e 7% da biomassa dos camarões. Outros três viveiros foram submetidos à despesca mista. Semanalmente, foram determinadas as seguintes variáveis da água: temperatura, oxigênio dissolvido, demanda bioquímica de oxigênio, pH, alcalinidade total, condutividade elétrica, nitrato, nitrito, nitrogênio amoniacal, nitrogênio total, ortofosfato solúvel, fósforo total, clorofila a, clorofila b, clorofila c, feofitina, turbidez e sólidos totais suspensos. Após 145 dias, realizou-se a despesca total em todos os viveiros. Não foi observado nenhum padrão de variação temporal das variáveis limnológicas ao longo do cultivo. Estas foram mais dependentes dos processos biológicos que ocorreram no interior dos viveiros do que da água de renovação. A ração diária teve pouco efeito sobre a qualidade da água dos viveiros do que da água de renovação. A ração diária teve pouco efeito sobre a qualidade da água dos viveiros, efluentes e nenhuma sobre os depósitos de carbono, nitrogênio e fósforo no fundo. De um modo geral, as variáveis limnológicas apresentaram baixa correlação entre si. Possivelmente, as características intrínsecas de cada viveiro tiveram maior efeito sobre a qualidade da água do que...
Abstract: Grow-out ponds are ecosystems at the first stages of ecological succession. In this research, a limnological study on grow-out ponds of Macrobrachium amazonicum subjected to different feed levels and harvest management was performed. Twelve 0.01 ha earthen ponds were stocked with 20 juveniles.m-2. Prawns fed commercial diet at a rate of 7 to 9% of biomass until 14a. week. Then, each three ponds were fed with 3%, 5% and 7% of prawn biomass. Three other ponds were subjected to selective harvest. After 145 days of stocking, all ponds were drained and harvested. The following water parameters were weekly determined: temperature, dissolved oxygen, oxygen biochemical demand, pH, total alkalinity, electrical conductivity, nitrate-N, nitrite-N, ammonia-N, total nitrogen, soluble orthophosphate, total phosphate, chlorophyll a, chlorophyll b, chlorophyll c, pheophytin, suspended total solids and turbidity. Limnological parameters did not show any temporal pattern. Exchange water and daily feeding slightly affected water quality and effluents. Carbon and nitrogen did not accumulated in water column or soil while phosphate was immobilized or trapped by the mud. Feeding rate and kind of harvest showed low effect on water quality, effluents and none on accumulation of carbon, nitrogen and phosphorus, in the mud. Correlation among water quality parameters are weak or absent. Data suggest that intrinsic characteristics of each pond play a major role on pond ecology
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Sheehan, Emma Victoria. « Ecological impact of the Carcinus maenas (L.) fishery 'crab-tiling' on estuarine fauna ». Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/2339.

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The ecological effects of the green shore crab Carcinus maenas (L.) fishery was investigated in estuaries on the south west coast of the UK. The fishery known as 'crab-tiling' involves 'crab-tilers' laying artificial refugia such as car tyres, guttering or roof tiles, intertidally in estuaries. 'Crab-tiles' are specifically laid on mudflats and sandflats to attract moutling crabs seeking refuge, these crabs are then collected to use or sell as bait for recreational angling. Many estuaries that are crab-tiled are subject to a range of International, European and National legislation as they are of great conservation importance. For example, they provide feeding grounds for migratory wading shorebirds, and nursery and feeding areas for commercially and ecologically important fishes. Little is known regarding the impacts of the crab-tiling fishery on the-estuarine ecosystem. The aim of this study was to identify the direct effects that crab-tiling has on estuarine fauna, allowing a better understanding of the implications of crab-tiling for ecosystem functioning, subsequently allowing conservation groups to manage crab-tiling activity based on ecologically informed decisions. Efforts to establish the main impacts of crab-tiling focused on infauna that live within sediments where crab-tiles are laid, on estuarine epifauna (such as crabs, birds and benthic fishes) which forage around crab-tiled habitat, and aquatic fauna which utilise the intertidal environment during high tide. To quantify the impact of crab-tiling on populations of the target organism, C. maenas, a mensurative experiment was conducted over six estuaries in south-west England, including three commercially tiled estuaries and three relatively not-tiled estuaries. Estuaries where commercial crab-tiling took place were found to support substantially larger population sizes of C. maenas than not-tiled estuaries although the C. maenas modal size class was smaller, suggesting that, in terms of C. maenas abundance, the effect of crab removal by fisheries was outweighed by the increase in habitat availability due to the presence of crab tiles. The diversity and abundance of wading birds feeding over mud flats was not affected by the presence of crab-tiles, though birds aggregated around the tiles when feeding; conversely, crab-tiles generally had an opposite effect on aquatic fauna, which tended to be more abundant in control sites than in crab-tiled sites. A possible explanation for these observations was associated with the concentration of crabs around the tiles: these localised crab populations could provide prey for wading shore birds, which were seen collecting C. maenas from crab-tiles, but could simultaneously predate on aquatic fauna; during high tide, tiled sites had the highest abundance of crabs, yet control sites had the highest abundance of all the other aquatic fauna. The crab-tiling fishery has been found to cause ecological impacts to a range of estuarine fauna. Changes in any one species abundance could have implications for that species' predator and prey; additionally the abundance mediated change in the ecological functions which they perform, will have consequences for ecological processes within the estuary as a whole. The indirect impacts occurring as a result of the direct effects measured here also need to be quantified so that the full effect that crab-tiling has for ecosystem functioning in estuaries can be understood and effectively managed.

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Sneddon, Lynne Ure. « The physiological effects of agonistic behaviour in the shore crab, Carcinus maenas (L.) ». Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264141.

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Waring, Tanya Claire Fiona. « Physiological and behavioural effects of environmental oestrogens on the shore crab (Carcinus maenas) ». Thesis, University of Portsmouth, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439042.

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Fehsenfeld, Sandra. « Linking acid-base balance with nitrogen regulation in the decapod crustacean, Carcinus maenas ». Comparative Biochemistry and Physiology, Part A, 2013. http://hdl.handle.net/1993/30977.

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As one of the most successful invasive species in the marine environment around the globe, the green crab Carcinus maenas possesses efficient regulatory mechanisms to quickly acclimate to environmental changes. The most important organs in this process are the nine pairs of gills that not only allow for osmoregulation, but have been shown to be involved in ammonia excretion and respiratory gas exchange. To date, however, little is known about the gills’ contribution to acid-base regulation that might become increasingly important in a “future ocean scenario” whereby surface ocean pH is predicted to drop by up to 0.5 units by the year 2100. The present thesis aims to characterize the green crab gills’ role in acid-base regulation and how it is linked to ammonia excretion. After exposure to hypercapnia (0.4 kPa pCO2 for 7 days), osmoregulating green crabs were capable of fully compensating for the resulting extracellular respiratory acidosis, while osmoconforming green crabs only partially buffered the accompanying drop in hemolymph pH after acclimation to 1% CO2 for 48 hours. Perfusion experiments on isolated green crab gills showed that different gills contributed to the excretion of H+ in an individual pattern and indicated that NH4+ is an important component of branchial acid excretion. Experiments on gill mRNA expression and pharmaceutical effects on isolated gills identified distinct epithelial transporters to play significant roles in branchial acid base regulation: Rhesus-like protein, basolateral bicarbonate transporter(s), cytoplasmic V-(H+)-ATPase, Na+/H+-exchanger, basolateral Na+/K+-ATPase, cytoplasmic and membrane bound carbonic anhydrase, and basolateral K+ channels. Regarding the latter, the present work provides the first sequence-based evidence for a potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel (CmHCN) capable of promoting NH4+ transport in the green crabs’ gill epithelium, and further demonstrates its direct involvement in branchial acid-base regulation. This highly conserved protein is a potentially important novel key-player in acid-base regulation in all animals. Interestingly, the observed principles linking acid-base to ammonia regulation in the decapod crustacean gill epithelium resemble many observations previously made in vertebrates. The data of the present thesis therefore provides valuable information for general acid-base regulation, while contributing substantially to our understanding of acid-base regulation in invertebrates.
February 2016

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Chisholm, June R. S. « Antibacterial activity in the blood cells of Carcinus maenas (L.) and other crustaceans ». Thesis, University of St Andrews, 1993. http://hdl.handle.net/10023/14859.

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In vitro antibacterial activity in the haemocytes of Carcinus maenas (L) was investigated. Haemocyte lysate supernatants (HLS) were assayed against twelve Gram-positive and Gram-negative marine bacteria, eight of which proved sensitive to the antibacterial factor or factors contained therein. Antibacterial activity was also found in HLS from four other marine crustaceans-Glyptonotus antarcticus, Galathea strigosa, Nephrops norvegicus and Crangon crangon. Activity in C. maenas HLS was independent of divalent cations, operated at high titre, was stable after treatment at 100 °C for 30 minutes and also after three months storage at -70 °C; it was present in the granular cells (which also contain the prophenoloxidase (proPO) activating system, a putative recognition mechanism in arthropods), but was absent from hyaline cells and plasma. In vitro studies were carried out to determine whether a relationship exists between the proPO system and the antibacterial activity in the haemocytes of C. maenas. It was shown that phenoloxidase and an activating serine protease were not responsible for the observed antimicrobial effects, although the possibility that activity resides with some other component of the proPO system has not been excluded. Seasonal variation in antibacterial activity, haemocyte counts and HLS protein concentrations was found, with conspicuous depression of antibacterial activity at two key points in the year. This occurred in conjunction with extremes of water temperature and it is proposed that the variation in antibacterial activity is due to underlying temperature effects on haemocyte counts and protein levels. Low levels of lytic activity against Micrococcus luteus cell walls and low levels of bacterial agglutination were recorded, but the powerful antibacterial activity in HLS could not be attributed to these alone. Gel filtration with Sephadex G-l00 revealed at least three antibacterial proteins of differing molecular size, with estimated MW of 72 kDa, 34 kDa and 4 kDa. The 72 kDa and 34 kDa proteins were bacteriostatic and the 4 kDa protein was bacteriolytic.

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Almeida, Maria João Maia Rocha de. « Pre- and post-settlement processes regulating recruitment of the shore crab Carcinus maenas ». Doctoral thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/958.

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Doutoramento em Biologia
O sucesso do recrutamento em espécies com ciclos de vida complexos, i.e. com duas ou mais fases de desenvolvimento, depende do fornecimento de larvas aos locais apropriados do assentamento (mecanismos de pré-assentamento) e na consequente sobrevivência destas larvas até aos estágios bentónicos iniciais (mecanismos de pós-assentamento). O estudo dos principais processos físicos que controlam a variabilidade intra-anual do recrutamento do caranguejo Carcinus maenas foi possível com à obtenção em séries diárias da abundância de megalopas no plâncton e do seu assentamento em substratos artificiais de assentamento, e de parâmetros físicos relacionados com a amplitude de maré e o upwelling, durante os meses da época reprodutiva deste caranguejo. Os nossos resultados demonstraram um padrão cíclico de fornecimento de megalopas de C. maenas aos estuários na costa ocidental de Portugal, relacionado com a amplitude de maré e favorecido pelos ventos de sul. O assentamento de megalopas nos substratos artificiais de assentamento mostrou-se desacoplado do fornecimento nos dois estuários. Os dados obtidos sugerem que as megalopas são transportadas para a costa após a acção de ventos de downwelling, e o fornecimento para os estuários ocorre por transporte selectivo por corrente de maré. A utilização de substratos artificiais para medir densidades de juvenis de Carcinus maenas deve ser ponderada, uma vez que se verificou que em habitats estruturalmente menos complexos os juvenis utilizam os colectores como refúgio; em habitats mais complexos, os juvenis preferiram refugiar-se nas ervas marinhas existentes. No entanto, a estimativa de abundâncias diárias medidas nos colectores permitiu a descrição das abundâncias dos vários estádios de desenvolvimento juvenis, bem como as respectivas taxas de crescimento. As capacidades locomotoras de diferentes classes de tamanho de juvenis de C. maenas foram estimadas mediante o cálculo de um índice de locomoção. Os nossos resultados sugerem que os juvenis mais pequenos estão relativamente protegidos em habitats com vegetação densa, provavelmente porque este tipo de habitats inibe os movimentos dos juvenis de maiores dimensões. Foram também encontradas evidências da existência de segregação temporal na actividade locomotora das diferentes classes de juvenis, que funcionará como um mecanismo que permite reduzir o canibalismo e, consequentemente, aumentar a capacidade de suporte dos habitats juvenis. Foi realizado um estudo sobre o canibalismo nos juvenis de C. maenas na Ria de Aveiro, in situ e utilizando densidades reais. Verificou-se que as presas mais pequenas eram as mais vulneráveis, sendo os juvenis de maiores dimensões os predadores mais eficazes. Por outro lado, as taxas de canibalismo foram menores em habitats com elevadas densidades de refúgio (Zostera noltii). A estimativa das taxas diárias de mortalidade devidas ao canibalismo são aproximadamente metade das taxas diárias de mortalidade devidas aos processos de pré-assentamento, indicando que esta população de C. maenas será regulada pelo fornecimento larvar, i.e., será uma população regulada essencialmente por mecanismos préassentamento.
The success of recruitment in complex life cycle species, i.e. with two or more developmental phases, is dependent on the supply of larvae to the appropriate settlement sites (pre-settlement processes) and on the subsequent survival of these larvae through the early benthic stages (post-settlement processes). The main physical processes that control intra-year variability of recruitment in the portunid crab Carcinus maenas were studied by obtaining daily series of abundance of megalopae in the plankton, settlement of megalopae on bottomdeployed collectors, and physical parameters related to tide amplitude and upwelling, during several months within the reproductive season. Our results demonstrated a cyclic pattern of supply of Carcinus maenas megalopae to estuaries on the west coast of Portugal, related to the tide amplitude. Furthermore, supply was enhanced by southerly winds. Settlement of megalopae on artificial settlement substrates deployed on the bottom was uncoupled to supply at both estuaries. Our results suggest that transport of C. maenas megalopae to the nearshore is accomplished by onshore advection following downwelling winds, and supply to the estuaries occurs by selective tidal stream transport. The use of artificial collectors to measure juvenile shore crab densities must be carefully considered as juveniles appear to use of the collectors as refuges in less complex habitat, while in more complex habitats crabs preferred to take shelter among the naturally-occurring seagrasses. Nevertheless, artificial collectors deployed daily allowed the description of the different juvenile instar abundances over time and the estimation of juvenile growth rates. The locomotory activity of different size classes of shore crab juveniles were assessed through the estimation of a locomotory index. Our results suggest that small juveniles are relatively protected under dense vegetation cover due to lower mobility of larger crabs, and evidence temporal segregation of activity windows between juvenile crabs of different size, which may be a key mechanism to reduce cannibalism and therefore increase carrying capacity of nursery habitats. Cannibalism in C. maenas juvenile shore was measured in situ and at natural densities. Smaller preys were the most predated and medium and large size of juveniles was the most successful predators. Also, rates of cannibalism diminished at higher densities of refuge (the seagrass Zostera noltii). In the case of Ria de Aveiro, the average daily mortality rates due to cannibalism is approximately half of the mortality caused by pre-settlement processes. These results suggest that this shore crab population is mainly regulated by larval supply, i.e., it is a pre-settlement regulated population.

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Mari, Jocelyne. « Recherches sur les maladies virales du crustacé décapode marin Carcinus mediterraneus Czerniavski, 1884 ». Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37607664z.

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SANTOS, Edson Pereira dos. « Utilização de diferentes dietas na larvicultura do camarão pitu, Macrobrachium carcinus (Linnaeus, 1758) ». Universidade Federal Rural de Pernambuco, 2006. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6276.

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The freshwater prawn Macrobrachium carcinus production had been commercially explored in several countries. In northeast, the prawn fishery has a great importance in Low São Francisco Basin. The large scale postlarvae production continues being the main problem for commercial culture and natural stocks maintenance. This work aimed to test different diets in Macrobrachium carcinus larval culture in order to improve the performance of prawn post-larvae production, with the utilization of fish flesh (Ff) and a formulated diet (Fd), or in association with adult artemia biomass (FfB and FdB, respectively), resulting in four treatments and six replicates. Were used twenty-four 20 L circular recipients provided of water recirculating and aeration systems, where were stocked 25 larvae (zoea V-VI) per liter. The diets were offered four times a day (07:00, 10:00, 13:00 and 16:00 hrs) during 49 days. Water temperature was 27.5±1.2ºC in the morning and 28.4±1.3ºC in the afternoon; the total ammonia nitrogen and nitrite were 0.2±0.2 and 0.5±0.8 mg/L, respectively, while pH and salinity maintained around 8.2 and 24, respectively. The average larval survival was 3.47±1.56, 7.40±2.99, 14.83±2.64 and 7.57±2.31, respectively for Ff, FfB, Fd and FdB treatments. Ff treatment obtained the lowest survival due to larvae reject by the fish flesh. Fdand FdB treatments showed significant difference (P≤0.05), with better survival obtained by FdB diet. The highest survival was obtained by the Fd diet (14.83%), that showed itself as the more appropriated alternative to use in M. carcinus hatchery, but the adult artemia biomass showed that could provide better survival rates when associated with other feeds.
A produção do camarão pitu Macrobrachium carcinus tem sido explorada comercialmente em diversos países. No Nordeste, a pesca do pitu é de grande importância no Baixo São Francisco. A produção em larga escala de pós-larvas do pitu continua sendo o principal empecilho para o cultivo comercial e recuperação dos estoques naturais. Desta forma, objetivou-se com o presente trabalho testar diferentes dietas na larvicultura de M. carcinus, visando melhorar o desempenho da produção de pós-larvas, com a utilização de músculo de peixe (Dp) e uma dieta formulada (Df), ou em associação à biomassa de Artemia sp (DpB e DfB, respectivamente), perfazendo quatro tratamentos em seis réplicas. Utilizaram-se 24 recipientes circulares de 20 L com sistemas de recirculação de água e aeração, nos quais estocaram-se 25 larvas (zoea V-VI) por litro. As dietas foram ofertadas em quatro horários (07:00, 10:00, 13:00 e 16:00h) durante 49 dias. Durante o cultivo registrou-se valores médios de 27,5 ± 1,2 ºC (manhã) e 28,4 ± 1,3 ºC (tarde) para temperatura, de 0,2 ± 0,2 mg/L para amônia total e de 0,5 ± 0,8 mg/L para nitrito, enquanto que o pH e a salinidade mantiveram-se em 8,2 e 24‰, respectivamente. Os percentuais de sobrevivência média das larvas foram 3,47 ± 1,56, 7,40 ± 2,99, 14,83 ± 2,64 e 7,57 ± 2,31%, respectivamente, para os tratamentos Dp,DpB, Df e DfB. No tratamento Dp obteve-se a menor (P≤0,05) sobrevivência, pelo fato das larvas rejeitarem o músculo de peixe triturado. As dietas Dp e DpB apresentaram diferença significativa (P≤0,05), com maior sobrevivência para a dieta DpB. A maior sobrevivência foi obtida pela dieta Df (14,83%), que se apresentou como a alternativa mais apropriada para a utilização na larvicultura de M. carcinus, entretanto a biomassa de artêmia adulta mostrou que poderá resultar em uma melhoria na taxa de sobrevivência quando associada com outros alimentos.

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Abbas, Saeed Abdulla Mohamed. « Predation of infaunal bivalves by Carcinus maenas (L.) in the Burry Inlet, South Wales ». Thesis, Swansea University, 1985. https://cronfa.swan.ac.uk/Record/cronfa43063.

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Moraes-Riodades, Patrícia Maria Contente. « Diferenciação morfotípica de machos de camarão de água doce Macrobrachium amazonicum (Heller, 1862) (Crustacea, Decapoda, Palaemonidae) / ». Jaboticabal, 2002. http://hdl.handle.net/11449/144172.

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Orientador: Wagner Cotroni Valenti
Banca: Gilson Luiz Volpato
Banca: Julio Vicente Lombardi
Resumo: Esse trabalho teve como objetivo verificar a possível existência de morfotipos em machos de M. amazonicum e definir as características para a sua identificação. Animais provenientres de viveiros de cultivo de todas as classes de tamanho foram analisados quanto a cor e espinação do segundo quelípodo direito. A seguir, foram medidos para determinação dos comprimentos total, pós-orbital, da carapaça, do quelípodo direito e dos cinco artículos que o compõem. As relações entre essas dimensões foram determinadas, utilizando-se técnicas para estudos de crescimento relativo. O trabalho mostrou que a população de M. amazonicum é composta por quatro grupos distintos, que diferem na morfologia dos quelípodos e em várias relações morfométricas. Isto confirma a hipótese da existência de morfotipos nessa espécie. Pode-se, portanto definir quatro morfotipos, que foram chamados "Translucent Claw" (TC), "Cinnamon Claw" (CC), "Green Claw" (GC) e "Green Claw linha" (GC'). Os machos TC são pequenos, apresentam o quelípodo translúcido, geralmente sem espinhos, providos ou não de botões (espinhos em formação), ou com espinhos pequenos formando um ângulo £ 60º. O morfotipo CC é constituído por animais com tamanho similar a TC, com a coloração tendendo a cor de canela e espinhos do quelípodo formando ângulo £ 60º. Os machos GC constituem um grupo de animais de grande porte em relação a TC e CC, com quelípodos desenvolvidos e maiores que o comprimento pós-orbital. Estes apresentam coloração verdemusgo, com espinhos em inclinação variando entre 60º e 90º. Os camarões que constituem o morfotipo GC' apresentam características semelhantes ao grupo GC em cor e espinação, mas o comprimento do quelípodo é proporcionalmente menor, sendo inferior ao comprimento pósorbital. A identificação de cada casta de machos de M. amazonicum possibilitará o prosseguimento de...
Abstract: The aim of this paper was to investigate the morphotypic differentiation of Macrobrachium amazonicum male. A key for identification of these morphotypes was provided using observations on color and spination of chelipeds supplemented by relative growth techniques. Prawns were taken from nine earthen ponds at Jaboticabal, São Paulo, Brazil. Total length, post-orbital length and the length of carapace, chelipeds and all limb joints were measured on the right second pereiopod with a vernier caliper. Four distinct morphotypes were identified, "Translucent Claw" (TC), "Cinnamon Claw" (CC), "Green Claw" (GC) and "Green Claw apostrophe" (GC' ). They differ by chelipeds morphology and several morphometric relationships. TC prawns are small in size and present chelipeds translucent with tubercles or spines, which point distally at an angle £ 60º. CC males are similar to TC in size and spination, but present cinnamon chelipeds. GC and GC' are large prawns with long dark green chelipeds provided with long and robust spines, which point distally at an angle ranging between 60º and 90º. They differ only by chelipeds proportion. GC cheliped length overtake post-orbital length while the opposite occurs in GC' males. Recognition of morphotypes will be useful for future biology and culture works aiming increase pond production of M. amazonicum
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Lopes, Alessandro Garcia. « Análises isoenzimáticas, moleculares e ultraestruturais em camarões dulcícolas do gênero Macrobrachium / ». São José do Rio Preto, 2014. http://hdl.handle.net/11449/122176.

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Orientador: Carlos Roberto Ceron
Banca: Ana Maria Bonetti
Banca: Lilian Madi Ravazzi
Resumo: Os camarões do gênero Macrobrachium (Crustacea, Decapoda, Palaemonidae), encontrados em ambientes de água doce, são amplamente distribuídos pelas regiões tropicais e subtropicais do mundo, inclusive em locais próximos ao litoral. Algumas espécies desse gênero, como por exemplo M. rosenbergii, apresentam valor econômico, sendo cultivadas e comercializadas como alimento. Na região Noroeste do Estado de São Paulo, são encontradas as espécies classificadas como M. amazonicum e M. jelskii, as quais são espécies exóticas de camarões dulcícolas recentemente introduzidas e amplamente disseminadas em reservatórios de usinas hidrelétricas desta região. Essas espécies possuem hábitos crípticos e noturnos, sendo predadores de larvas de peixes e também presas de peixes adultos e outros organismos. M. amazonicum e M. jelskii apresentam grande similaridade interespecífica em termos de caracteres morfológicos, o que pode dificultar a classificação taxonômica desses organismos. O objetivo deste estudo foi conduzir análises morfométricas, ultraestruturais, isoenzimáticas e moleculares em M. amazonicum e M. jelskii, na tentativa de obter-se novos dados para distinguí-los. Os camarões foram coletados das populações dos reservatórios de Sales/SP e Mendonça/SP. As análises morfométricas englobaram as medidas do télson, dos espinhos caudais internos e do rostro. As análises por microscopia eletrônica de varredura foram realizadas nas estruturas do télson, nos espinhos caudais internos e no apêndice masculino. As análises isoenzimáticas, realizadas por eletroforese em gel de poliacrilamida, abrangeram as enzimas álcool desidrogenase, octanol desidrogenase, glicose-6-fosfato desidrogenase, lactato desidrogenase, amilase e esterases do hepatopâncreas e tecido muscular. Análises moleculares envolveram a amplificação do espaçador intergênico interno ITS-1 (Internal Transcribed Spacer 1) do rDNA. Os fragmentos ...
Abstract: Prawns of the genus Macrobrachium (Crustacea, Decapoda, Palaemonidae) can be found in freshwater environments, widely distributed throughout tropical and subtropical regions of the world, including regions near the coast. Some species of this genus, for example Macrobrachium rosenbergii, present economic value, which are reared and traded as food. In the northwest region of São Paulo State two exotic freshwater prawn species are found, classified as M. amazonicum and M. jelskii, which were recently introduced to the aquatic reservoirs of hydroelectric power plants and then, disseminated throughout reservoirs in this region of the State. These species have cryptic and overnight habits, being predators of fish larvae and also being prey to adult fishes and other organisms. M. amazonicum and M. jelskii present high rates of interspecific similarity in terms of morphological characters, which are generally used to distinguish them, what may induce mistakes in taxonomic identification. The objective of this study was to conduct morphometric, ultrastructural, isoenzymatic and molecular analyses of M. amazonicum and M. jelskii, in order to obtain more data about their differentiation. The prawns were collected in reservoirs of Sales/SP and Mendonça/SP. Morphometric analyses were performed involving the structures of telsons, internal caudal spines and rostrums. Scanning electron microscopy analyses were performed on structures of telsons, internal caudal spines and male appendices. Isoenzymatic analyses by polyacrylamide gel electrophoresis included the enzymes alcohol dehydrogenase, octanol dehydrogenase, glucose-6-phophate dehydrogenase, lactate dehydrogenase, amylase and esterases of hepatopancreas and muscle tissue. Molecular analyses were performed by amplification and sequencing of ITS-1(Internal Transcribed Spacer 1) intergenic spacer from rDNA. The amplificated fragments were used for analyzing length polymorphism restriction fragments ...
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Griffen, Blaine David. « Interactions between two invasive crab predators, Carcinus maenas and Hemigrapsus sanguineus, and consequences for the native community / ». Restricted access (UM), 2007. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.

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Saver, Michelle Anne. « The effect of pericardial organ hormones on shore crab, Carcinus maenas, hearts and cardiac ganglia ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24559.pdf.

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Lawson, Sarah Louise. « Effect of copper on the gill structure of a euryhaline crab, Carcinus maenas (Crustacea : Decapoda) ». Thesis, University of Plymouth, 1994. http://hdl.handle.net/10026.1/2708.

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A posterior gill of the common shore crab Carcinus maenas (Crustacea:Decapoda) was used to study the effects of sublethal copper concentrations on gill morphometry, and gill cell ultrastructure and distribution. Primarily, the ultrastructure and distribution of gill cells in the untreated gill of crabs acclimated to 35‰ seawater were characterised. Gill ultrastructure was subsequently shown to vary markedly at 10‰ compared to 35‰ seawater. Ultrastructural and distributional, rather than gross morphological, change occurred in the gill following exposure to copper at each salinity. Ultrastructural studies showed that as the length of copper exposure increased the gill epithelial layer became highly vacuolated, the number of plasma membrane infoldings and mitochondria became reduced, the microtubular network became disrupted, the endoplasmic reticulum became swollen and the cell cytoplasm contained many free ribosomes. Copper exposure also resulted in an increase in the number of haemocytes in the gill, some of which became attached to the basal epithelial cell surface or actually infiltrated into the epithelial cell cytoplasm. Ultrastructural change was more extensive when copper was administered at 35‰ rather than 10‰ seawater. These effects are described and correlated with previously documented biochemical and physiological responses to heavy metals in crustaceans. In addition, the elemental composition of the gill granular haemocytes suggested they play an important role in the immobilisation and removal of copper-from the gill. This study has shown the way forward in creating a better understanding of the mechanisms behind heavy metal toxicity in marine organisms is the use of environmentally realistic concentrations of heavy metal administered in flow-through seawater systems.

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Jones, Deborah Ruth. « Aspects of the reproductive biology of the crabs Inachus dorsettensis (Majidae) and Carcinus maenas (Portunidae) ». Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241463.

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Zinebi, Hassan. « Étude électrophysiologique de la flexibilité d'expression de l'activité motrice respiratoire chez le crabe Carcinus maenas ». Bordeaux 1, 1991. http://www.theses.fr/1991BOR10512.

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L'activite motrice respiratoire du crabe carcinus maenas s'exprime avec une grande flexibilite qui concerne notamment la frequence du rythme respiratoire. Trois types de mecanismes paraissent etre fortement impliques dans cette flexibilite. Il s'agit: 1) de l'existence d'une population originale de chemorecepteurs peripheriques arteriels. Ces chemorecepteurs sont responsables au moins en partie de l'augmentation importante de la frequence du rythme respiratoire lorsque la teneur en o#2 diminue dans le milieu et inversement; 2) de l'expression par les muscles ventilatoires de proprietes regeneratives inhabituelles chez les invertebres (potentiels d'action musculaires et activites oscillantes). Ces proprietes sont toujours associees a des activites mecaniques importantes du muscle, ce qui permet au systeme neuromusculaire de participer de facon active a l'expression de l'activite motrice respiratoire; 3) de l'existence d'un systeme neurosecreteur (le systeme pericardique) qui etablit des relations anatomiques intimes avec le systeme respiratoire. La mise en jeu de ce systeme modifie l'expression de l'activite rythmique respiratoire et ceci en agissant a la fois sur l'oscillateur respiratoire central et sur l'effecteur musculaire. L'apport exogene de neuromodulateurs presents dans ce systeme (comme la serotonine, l'octopamine et la proctoline) provoque des effets similaires a la mise en jeu du systeme pericardique, ce qui laisse penser qu'elles sont liberees par ce meme systeme

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Goblet, Christiane. « Les mécanismes de la contraction musculaire : étude sur la fibre musculaire du crabe : Carcinus maenas ». Lille 1, 1986. http://www.theses.fr/1986LIL10029.

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Le mécanisme permettant l'accroissement de la concentration calcique intracellulaire a été étudié sur les fibres musculaires intactes et pelées de C. Maenas. Ce mécanisme de libération calcique par le réticulum sarcoplasmique est de type "ca-induced ca-release. " de plus l'atpase calcique située dans la membrane du Rs semble intervenir par une modulation du mécanisme précédent par l'ADP. Un autre cation divalent, le strontium stimule lui aussi le largage des ions calcium avec cependant moins d'efficacité

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SAIDI, BASSIMA. « Mecanisme d'action d'une neurohormone, la mih ou molt-inhibiting hormone chez le crabe carcinus maenas ». Paris 6, 1995. http://www.theses.fr/1995PA066204.

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La mue des crustaces est controlee par des hormones de mue ou ecdysteroides synthetises par les glandes de mue (= organes y), elles-memes sous le controle inhibiteur d'un neuropeptide, la mih (=molt-inhibiting hormone), synthetisee et secretee par les pedoncules oculaires. La determination du mode d'action de la mih chez le crabe carcinus maenas nous a d'abord amenes a mieux preciser les modalites de la steroidogenese et a montrer que l'activite des organes y, qui produisent deux molecules, l'ecdysone (e) et la 25-desoxyecdysone (25de), varie en fonction du cycle de mue, et que la 25de est largement predominante en premue. La mih inhibe la synthese de ces deux ecdysteroides de maniere dose-dependante, mais inhibe preferentiellement celle de la 25de ; cette inhibition est decelable tres rapidement (apres 5 min), et s'avere irreversible au-dela de 2h d'incubation. Ce neuropeptide provoque, des son application (1 min), une augmentation de 2 nucleotides cycliques, l'ampc et le gmpc, le premier de maniere transitoire et le second de maniere continue. En premue comme en intermue, le 8br-gmpc reproduit les effets inhibiteurs de la mih, tandis que les effets d'autres agents pharmacologiques dependent de la dose utilisee et de l'etat physiologique des animaux. L'analyse des activites kinasiques a revele la presence predominante de la pkg, alors que la pka n'est decelable, et en faible quantite, qu'en premue. Ces resultats font du systeme gmpc-pkg la composante majoritaire du mecanisme de transduction de la mih, tandis que le systeme ampc-pka jouerait un role activateur en premue. Ils revelent egalement un phenomene de cross-activation, qui explique l'aptitude des analogues de l'ampc a mimer l'action de la mih en intermue. Ils permettent de regrouper nos donnees avec celles, contradictoires, de la litterature, et de proposer un schema general de regulation des organes y qui se rapproche de celui des glandes surrenaliennes des vertebres

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Goblet, Christiane. « Les Mécanismes de la contraction musculaire étude sur la fibre musculaire du Crabe Carcinus maenas ». Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37597932v.

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Proença, Danilo Cintra. « Aplicação de indicadores e índices para avaliar a sustentabilidade ambiental em um sistema de aquicultura integrado e multitrófico com diferentes substratos / ». Jaboticabal, 2013. http://hdl.handle.net/11449/90046.

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Orientador: Wagner Cotroni Valenti
Banca: Iracy Lea Pecora
Banca: Mara Cristina Pessoa da Cruz
Resumo: A aquicultura é a atividade de produção de alimentos que mais cresce no mundo e tem sido criticada por seus impactos ambientais negativos. O caminho em direção da sustentabilidade é incerto e precisa ser avaliado. Foi utilizado um conjunto de indicadores para avaliar a sustentabilidade em um sistema de aquicultura integrado e multitrófico, usando espécie bentônica e nectônica combinadas com dois tipos de substratos. Um estudo de 5 meses foi realizado utilizando três diferentes tratamentos em um delineamento inteiramente casualizado: controle, sem substrato (WS); substrato manto geotêxtil (GS), e substratos de bambu (BS). Densidade de estocagem foi de 22 camarões m-2 e 1,1 tilápias m-2 para os tratamentos. As tilápias foram alimentadas com ração, aproximadamente 5-1% de sua biomassa, de acordo com a fase de desenvolvimento. A sustentabilidade ambiental foi medida com base na utilização de recursos naturais, a eficiência na utilização de recursos, a poluição liberada para o meio ambiente e o risco da espécie cultivada. Um índice de sustentabilidade ambiental foi criado a fim de avaliar qual o tratamento era mais sustentável. Os resultados mostraram que a GS melhorou a utilização dos recursos e BS a melhor eficiência da utilização dos recursos, além de melhorar a qualidade do sedimento. Apesar das vantagens da utilização de substrato, WS foi considerado o sistema mais sustentável. O uso de substratos não aumentou a sustentabilidade, devido principalmente a questão de emissão de gases
Abstract: Aquaculture is the food production activity that grows faster than any other in the world and has been criticized for its environmental negative impacts. The path toward sustainability requirements is uncertain and needs to be evaluated. We used a set of indicators to assess the sustainability of integrated aquaculture multispatial and multitrophic systems, using a benthonic and a nektonic omnivorous species combined with two types of substrates. A 5-month study was conducted using three different treatments in a completely randomized design: control, without substrate (WS); geotextile mantle substrate (GS); and bamboo substrate (BS). Stocking density was 22 prawns m-2 and 1.1 tilapias m-2 for all treatments. Tilapia was fed about 5-1% of their biomass, according to the development phase. Environmental sustainability was measured based on the use of natural resources, efficiency on the use of resources, pollution released to environment and risk of cultivated specie. An environmental sustainability index was created in order to evaluate which treatment was more sustainable. Results have shown that GS improved the use of resources and BS had the best efficiency of the use of resources and enhanced the sediment quality. Despite of the advantages of using substrate, WS was considered the most sustainable system. The use of substrates did not increase the sustainability due mainly to gas emission issue
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Hamer, Mark S. « THE PROTEOMIC RESPONSE OF THE CARCINUS MAENAS Y-ORGAN OVER THE COURSE OF THE MOLT CYCLE ». DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1374.

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Molting in arthropods is a complex process governed by regulatory mechanisms that have evolved and adapted over millennia to allow these animals to grow, despite being confined by a hardened exoskeleton. We isolated the molt-regulating Y-organs (YO) from the common shore crab Carcinus maenas at molt stages B, C1-3, C4, and D0 to assess how changes in protein abundances might underline the unique physiology of each of these stages. We found that changes in protein abundance were most notable in the postmolt stages (B and C1-3), where an increase in energy metabolism and the reactive oxygen species stress (ROS) response proteins was observed. An increase in triosephosphate isomerase and transketolase suggest that the postmolt YO is participating in triglycerides storage and is also actively recycling excess ribose sugars manufactured during the YO’s previously activated state. We also propose as mechanism through which ROS-induced release of cyclophilin A may contribute to YO atrophy during postmolt through the remodeling of structural proteins such as collagen. We support the standing observation of YO atrophy during postmolt by drawing attention to hemolymph protein abundances, especially those of cryptocyanin isoforms, which dropped precipitously in intermolt (C4) and remained at low abundances into early premolt (D0). Finally, though our evidence is preliminary, we propose that future investigations into the YO proteome address the significance of the protein glutamate dehydrogenase. Glutamate dehydrogenase, a key enzyme involved in the formation of glutamate, represents a potential nutrient-sensing checkpoint that might be involved in YO activation. Historically, most attention has gone to the acute molt stages, where signaling mechanisms involved in the activation of the YO have been the focus. Here, we present data suggesting that other regulatory mechanism may be governing the atrophy the postmolt YO. A better understanding of crustacean physiology has the potential to benefit ecosystems and economies worldwide.

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Johnson, Ian Trevor. « Studies on some responses of Carcinus maenas (L.) and other brachyurans to hypoxia and aerial exposure ». Thesis, University of Hull, 1985. http://hydra.hull.ac.uk/resources/hull:11281.

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This work comprises a series of investigations of the effects of changes in environmental oxygen levels, which occur with hypoxia or aerial exposure, on the osmo-regulatory capacity, acid-base balance and general respiratory physiology of brachyuran crabs. The principal species studied was Carcinus maenas, although Cancer pagurus and Liocarcinus puber were also included in the aerial exposure experiments. The effects of exposure to 4hr of moderate (Pw02 = 40 torr) or severe (Pw02 = 20 torr) hypoxia at 15°C on various blood solutes, acid-base balance and general respiratory physiology were assessed for C.maenas in low salinity (10.0, 13.5 and 19.0%.S) and fully marine (30.0%.S) media. Haemolymph pH increased at all test salinities and to an extent which was salinity/Pw02 dependent. During hypoxia the heart rate (fh) was not significantly affected at any salinity but the scaphognathite rate (fsc ) increased significantly (P<0.05) at all the media tested. Scaphognathite rate changes were greater in moderate rather than severe hypoxia. In hypotonic media hypoxia produced no changes to circulating Na+ or Mg2+ levels or to the Δ°C values but circulating Cl- levels fell and Ca2+ and lactate levels increased at salinity/ Pw02 dependent rates and extents. In the 30.0% S medium, no changes to any of the above blood ions occurred during moderate hypoxia but Ca2+ and lactate levels increased at Pw02 = 20 torr. At all test salinities original levels of blood Cl-, Ca2+ and lactate were regained within 4hr of re-oxygenation Pw02 = 130 torr). The implications of these findings have been considered in relation to the distribution of regulating species of crustaceans generally. The effects of 24hr severe (Pw02 = 20 torr) hypoxia on haemolymph protein synthesis in fed and starved C.maenas in 13.5%.S and 30.0%.S media were studied. Blood total protein levels were higher in animals acclimated to 13.5% S whereas haemocyanin levels were higher in the 30.0%.S group. A negative linear relationship between relative haemocyanin and blood total protein was observed in animals at both salinities. In fed animals small, but non-significant (P>0.05) increases in haemocyanin and total blood protein levels were recorded at both salinities (cf. normoxic animals). In starved groups at both salinities blood protein levels were maintained under hypoxia but control animals showed a fall in protein levels. The responses of the crabs C.maenas, C.pagurus and L.puber to short (4hr) and longer (24hr) term aerial exposure were investigated. On exposure to air oxygen consumption (M02) was reduced significantly (P<0.05) in C.pagurus and L.puber (cf. aquatic respiration rates), but the M02 of C.maenas in air was comparable to that in water. No marked change in fH or f sc were recorded in C.maenas during re-immersion following aerial exposure but in L.puber tachycardia and hyperventilation were observed. In air (4hr) there were no changes to blood lactate levels in C.maenas but pronounced changes were found in C.pagurus and L.puber. Long-term aerial exposure resulted in mortalities and significant (P

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Dissanayake, Awantha. « Evaluating the impact of organic contamination upon the physiology of the shore crab Carcinus maenas (L.) ». Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/1113.

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This thesis has focused on answering fundamental questions regarding the 'normal' physiological ranges of the male shore crab Carcinus maenas. knowledge of the responses to environmental variables is needed before the effects of anthropogenic stress can be identified. Anthropogenic stress was imposed in the form of contamination by a ubiquitous priority pollutant of the aquatic environment (polyaromatic hydrocarbon, pyrene). The first hypothesis focused on identifying the physiological differences between juvenile and adult male shore crabs. Differences at the cellular level (cell and immune function) determined the relative contaminant sensitivity between the two ontogenetic stages, with juveniles expressing increased physiological sensitivity to contaminant-imposed effects compared to adults. Further questions relating to how the physiological condition of Carcinus maenas was altered by nutritional stress were examined in the adult stage. Physiological 'competency* or tolerance was shown to be dependent upon organism nutritional status. Shore crab physiological condition was robust to short-tenn starvation. This is interpreted to resultfrom autophagy induction, whereby, when diet is restricted, energy is released via metabolism of protein, carbohydrate and lipid stores. The physiological implications of sublethal contaminant exposure under short-temi induction included'increased antioxidant status, signalling activation of compensatory mechanisms under contaminant-mediated challenge. The behavioural implications of nutritional status and contaminant exposure were investigated by staging intraspecific agonistic contests between pairs of shore crabs for a food resource. Behavioural evidence revealed that the competitive ability (resource holding potential) of individuals was higher in pyrene-exposed compared to unexposed crabs, with higher proximate associated costs (energy expenditure) of entering agonistic contests in starved compared to fully-fed individuals. Shore crab competitive ability was concluded to be dependent upon the physiological condition of the contestant. The final hypothesis investigated 'seasonal' differences in the physiology of Carcinus maenas to test whether there were any 'windows of sensitivity' to both environmental and contaminant-imposed challenges. The 'normal' pattern of seasonal variability was assessed from crabs collected from the Avon Estuary. Differences included higher imhiune function and lower antioxidant status between winter and spring compared to summer to autumn. These seasonal differences were shown to impact on the ability of shore crabs to respond to PAH exposure. Seasonal evaluation of shore crab physiological condition from estuaries of varying PAH input [Avon Estuary (low anthropogenic exposure) and Plym Estuary (relatively high anthropogenic exposure)], revealed significant seasonal differences between crabs as signalled by cellular endpoints (cellular integrity and viability) between January and June compared to July to December. In summary, this study has revealed that shore crab physiology varies with intrinsic (age, nutritional status) and extrinsic (temperature) factors. Therefore, it is essential to establish the full extent of the 'normal' physiological ranges for C. maenas physiology to completely understand the impact of environmental and anthropogenic stress alike.

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Queiroga, Henrique. « Processos de dispersão e recrutamento das larvas do caranguejo Carcinus Maenas (L.) na Ria de Aveiro ». Doctoral thesis, Universidade de Aveiro, 1995. http://hdl.handle.net/10773/978.

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Hamilton, Neil McLeod. « Respiratory and circulatory changes accompanying aquatic treadmill exercise of Carcinus maenas (L.) and Homarus vulgaris (M.E.) ». Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010228.

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Respirometers were designed which allowed the exercise physiology of Carcinus maenas (L.) and Homarus vulgaris (M.E.) to be examined in an aquatic environment. A treadmill system, incorporated into each respirometer, was used to induce exercise at a known velocity. The rate of oxygen consumption, (VO2), of Carcinus maenas exercised at different velocities was examined. It was found that at each velocity, VO2 reached a steady state. The steady state VO 2 was found to be linearly related to velocity. The VO2 of inactive animals, and the maximal rate of oxygen consumption were both found to be linearly related to animal live weight. The VO2, rate of heart beat (fH) and rate of scaphognathite beat (fScaph) of both C. maenas and H. vulgaris were measured prior to, during and after exercise, at one specific velocity. Various haemolymph gas parameters were also measured. In both species, the VO2, f H and FScaph increased at the onset of exercise until a steady state was achieved. Estimates of the rate of branchial water flow for C. maenas suggest that this parameter also increased as a result of exercise. The rate of blood flow increased as a result of excerise in both species, achieved by an increase in the rate of heart beat and stroke volume of the heart. In vitro oxygen equilibrium curve determinations suggest that at the velocities examined, a Bohr shift plays a minimal role in increasing oxygen delivery to the tissues during exercise of the two species. No significant change in haemolymph carbon dioxide tension or total gas content was found in either species, suggesting that gas exchange across the respiratory surface was not impared during exercise. In C. maenas, whole body and haemolymph L-lactate concentration increased as a result of exercise. No increase in haemolymph L-lactate was observed after exercise in H. vulgaris.

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El, Haj Alicia J. H. « An analysis of the growth of the walking leg muscle in Carcinus maenas and Homarus americanus ». Thesis, University of Aberdeen, 1985. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU356263.

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1) The carpopodite extensor muscle of Carcinus maenas and Homarus americanus demonstrated regional localization of at least three types of fibre: fast phasic, slow tonic and intermediate. A specific area of the extensor, area 1, was identifiable in extensors from different animals and comprised fast phasic fibres in Carcinus and intermediate fibres in Homarus. When the M-C joint of the leg was held at a 90° angle, the sarcomeres in area 1 fibres were at rest length. Measurements of sarcomere length taken in the middle peripheral region were indicative of sarcomere lengths in other regions of the intermoult fibre. 2) The mechanism of growth of the fibres was determined in intermoult animals of increasing size. Fibres increased in length by the addition of sarcomeres and increased in width by an increase in the number of myofybrils. Myofibrils increased in size by the addition of thick and thin filaments in the characteristic lattice arrangement. The number of myofibrils may increase by myofibrillar splitting as has been previously described for vertebrate muscle. Fibre number remained constant with growth of the animal. There was a decrease in mitochondrial density with increase in fibre area. 3) Over ecdysis, fibres lengthened by addition of short sarcomeres to the exoskeletal region of the fibre. During the 3-4 days postecdysial expansion of the exoskeleton, these short sarcomeres increased in length. hypothesis that these short sarcomeres are precursor sarcomeres being added during ecdysis was investigated. When intermoult muscle was held in a stretched position for 2 weeks, there was a regional increase in the length of the muscle similar to the increases found over ecdysis. In contrast, fibre area did not increase over ecdysis. Instead, fibre area increased during the late postmoult and intermoult. The frequency distribution of myofibril size altered over ecdsysis; large myofibrils were more commonly present during premoult than during the immediate postmoult. Lateral stretch on the muscle during ecdysial expansion of the exoskeleton may be the stimulus for myofibrillar splitting. Possible satellite cells were identified in the skeletal muscle fibres-. vitro and jLn vivo radiolabelling techniques were adapted for the carpopodite extensor muscle of Carcinus maenas. The levels of free phenylalanine, total bound protein and phenylalanine bound in the muscle protein increased with size of the muscle. The mean in vitro rate of synthesis or FSR in the intermoult animal was 0.3% per day and the in vivo rate of synthesis at 1.24% per day. The FSR remained constant with size of the extensor muscle in intermoult animals. Fixatives may have an effect on the specific activity in the bound fraction of the muscle which is attributable to binding artifacts of the free amino acids. 5) The levels of phenylalanine in the free pool fluctuated during the moult cycle. The protein/wet weight ratio of the muscle also varied with the moult cycle. Increases in protein during the early postmoult supported other evidence for growth of the muscle over ecdysis. Synthesis rates were raised during the premoult and immediate postmoult period and remained slightly elevated during the late postmoult. These increases in rate corresponded to periods of muscle growth. 6) Autoradiographic techniques combined with measurements of bound specific activity revealed an increase in activity in the exoskeletal or cuticular region of the fibre corresponding to the region of new muscle synthesis over ecdysis. No differences in grain density were found between fast phasic and slow tonic fibres or between the central and peripheral region of the myofibril in intermoult muscle. Regional localization of grains was found at the light microscope level in the Z, I and B bands but no further evidence of this differentiatial labelling was found at the electron microscope level.

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Mascaro, Maite. « Crab foraging behaviour : prey size and species selection in Carcinus maenas (L.) and Cancer pagurus L ». Thesis, Bangor University, 1998. https://research.bangor.ac.uk/portal/en/theses/crab-foraging-behaviour--prey-size-and-species-selection-in-carcinus-maenas-l-and-cancer-pagurus-l(402c594d-fe2f-42be-a39e-349cf07afff2).html.

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This thesis examines the foraging behaviour of Carcinus maenas and Cancerpagurus when presented with bivalves of contrasting morphology: Mytilus edulis, Ostrea edulis, Crassostrea gigas and Cerastoderma edule. Because foraging may be influenced by the relative abundance and morphological characteristics of both predator and prey, these aspects are also considered. Chelal size and strength of these crabs and prey shell shape largely determined handling techniques. When offered a size range of these bivalves individually, crabs attacked all encountered prey but rejected those that remained unbroken after several opening attempts, thus, emphasising the passive nature of their size-selective feeding. When offered paired combinations of mussels, oysters and cockles, larger crabs selected species in the ranked order of their profitability. Species-related preferences exhibited by crabs feeding on prey at or near the optimal size suggest that foraging decisions are partly based on evaluations of overall prey shape and volume, and that shell width constitutes an important feature which crabs recognise and associate with prey value. Variations in crab strength relative to size accounted for most intra-specific differences in foraging behaviour. Juvenile C maenas are limited in their choice of prey size, and are thus less species-selective. Adult C maenas are not so constrained, and exhibit a higher degree of species-selectivity. C. pagurus possesses powerful monomorphic chelae that operate at higher mechanical advantage than the cbelae of C maenas, and readily crushed larger mussels relative to their size. Differences in prey size selection between crab species varied with the species of prey offered, suggesting that certain shell features of these bivalves constitute effective barriers to even the powerful chelae of C pagurus. These results are relevant in the context of aquaculture, since predatory impact on commercially reared bivalves might be reduced by combining different prey species that offer predators alternative or preferred sources of food.

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Thèses sur le sujet « Carcinus »

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