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Dissertations / Theses on the topic 'Fishes'

Author: Grafiati

Published: 4 June 2021

Last updated: 29 July 2024

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1

O'Sullivan, Martha. "Population structure of demersal fish species in the north eastern Atlantic." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources. Restricted: no access until Dec. 31, 2010. Online version available for University members only until June 2, 2011, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=26063.

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2

Muhling, Barbara A. "Larval fish assemblages in coastal, shelf and offshore waters of South-Western Australia /." Access via Murdoch University Digital Theses Project, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20061129.110448.

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3

Fok, Man-sze Milla. "Baseline survey of fish juvenile assemblages in Tolo Harbour and Channel, Hong Kong." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B39633962.

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4

McRae, Lorelie Biggs 1963. "Surimi: The development of a new testing method." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/291467.

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Eight samples of varying qualities and ages of surimi were used in the development of a new method for testing the quality of surimi. The effects of salt, pH, concentration, heating temperatures and times, and cooling times were observed. These results were used in the development of the McRae-Manning Test. By employing this method, it was possible to determine the difference between fresh high quality surimi, fresh low quality surimi, and old surimi. For this test, surimi was mixed at a 15% concentration, heated at 90 C for 20 minutes in plastic syringes, cooled and evaluated. The surimi was evaluated by emptying the samples onto prepared transparent sheets and measuring how far the sample spreads with time. The transparent sheets had circular measurements which indicated the amount of spread. Best results were obtained when the sheets were elevated at one end.

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5

George, Sarah N. "Selectivity of coral reef fishes in a Caribbean trap fishery." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ36446.pdf.

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6

Duncan, Murray. "The genetic stock structure and distribution of Chrysoblephus Puniceus, a commercially important transboundary linefish species, endemic to the South West Indian Ocean." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1011868.

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Chrysoblephus puniceus is an over-exploited linefish species, endemic to the coastlines off southern Mozambique and eastern South Africa. Over-exploitation and habitat loss are two of the biggest threats to the sustainability of fisheries globally. Assessing the genetic stock structure (a prerequisite for effective management) and predicting climate related range changes will provide a better understanding of these threats to C. puniceus which can be used to improve the sustainability of the fishery. Two hundred and eighty four genetic samples were collected from eight sampling sites between Ponta da Barra in Mozambique and Coffee Bay in South Africa. The mitochondrial control region and ten microsatellite loci were amplified to analyse the stock structure of C. puniceus. The majority of microsatellite and mtDNA pairwise population comparisons were not significant (P > 0.05) although Xai Xai and Inhaca populations had some significant population comparisons for mtDNA (P < 0.05). AMOVA did not explain any significant variation at the between groups hierarchical level for any pre-defined groupings except for a mtDNA grouping which separated out Xai Xai and Inhaca from other sampling sites. SAMOVA, isolation by distance tests, structure analysis, principle component analysis and spatial autocorrelation analysis all indicated a single population of C. puniceus as being most likely. The migrate-n analysis provided evidence of current driven larval transport, with net migration rates influenced by current dynamics.Two hundred and thirty six unique presence points of C. puniceus were correlated with seasonal maximum and minimum temperature data and bathymetry to model the current distribution and predict future distribution changes of the species up until 2030. Eight individual species distribution models were developed and combined into a mean ensemble model using the Biomod2 package. Winter minimum temperature was the most important variable in determining models outputs. Overall the ensemble model was accurate with a true skills statistic score of 0.962. Binary transformed mean ensemble models predicted a northern and southern range contraction of C. puniceus' distribution of 15 percent; by 2030. The mean ensemble probability of occurrence models indicated that C. puniceus' abundance is likely to decrease off the southern Mozambique coastline but remain high off KwaZulu-Natal. The results of the genetic analysis support the theory of external recruitment sustaining the KwaZulu Natal fishery for C. puniceus. While the high genetic diversity and connectivity may make C. puniceus more resilient to disturbances, the loss of 15 percent; distribution and 11 percent; genetic diversity by 2030 will increase the species vulnerability. The decrease in abundance of C. puniceus off southern Mozambique together with current widespread exploitation levels could result in the collapse of the fishery. A single transboundary stock of C. puniceus highlights the need for co-management of the species. A combined stock assessment between South Africa and Mozambique and the development of further Marine Protected Areas off southern Mozambique are suggested as management options to minimise the vulnerability of this species.

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7

Franckowiak, Ryan Patrick. "Temporal dynamics of genetic variation within the Escanaba Lake walleye population : implications for managing the genetic resources of naturally recruiting walleye populations /." Link to Full-text, 2005. http://epapers.uwsp.edu/thesis/2006/Franckowiak.pdf.

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8

Woolley, Lindsey. "The development of a practical diet for juvenile dusky kob, Argyrosomus japonicus, for the South African mariculture industry." Thesis, Rhodes University, 2009. http://eprints.ru.ac.za/1568/.

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9

McLean, Jennifer Elizabeth. "Reproductive success of hatchery and wild steelhead, Oncorhynchus mykiss /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/5327.

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10

Upton, Harold F. "The economic consequences of fish habitat conservation and management /." View online ; access limited to URI, 2004. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3135922.

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11

Haughey, Joanne Lee. "Culverts as potential barriers to fish movement." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 65 p, 2007. http://proquest.umi.com/pqdweb?did=1251899181&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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12

Rinne, John N. "Flows, Fishes, Foreigners and Fires: Relative Impacts on Southwestern Native Fishes." Arizona-Nevada Academy of Science, 2003. http://hdl.handle.net/10150/296624.

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13

Mead, Angela. "The role of restocking in enhancing marine fisheries : a way forward /." Thesis, View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34737911.

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14

Pienaar, Anthony Graham. "A study of coeval sibling cannibalism in larval and juvenile fishes and its control under culture conditions." Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1005469.

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The primary objective of this study was to examine environmental parameters thought to affect cannibalism in certain fish species. It was found that environmental, behavioural, genetic and physiological factors all affect cannibalism in the species exhibiting the phenomenon. The diversity of factors nfluencing cannibalism served to illustrate the complexity of this behaviour pattern. Feeding to satiation was found to suppress cannibalism in catfish, trout and koi carp. High population densities were found to increase the rate of cannibalism, thereby acting as a population regulation mechanism for catfish, trout and the common and koi carps. Live food, as compared with dry pelletized feed was found to significantly suppress cannibalistic aggression. Catfish grown in total darkness, provided with refuges and living in turbid conditions were found to exhibit lowered cannibalistic and territorial aggression. Various lines of evidence suggested that cannibalism has a genetic basis, as was shown by the differences in cannibalistic behaviour of the two strains of Cyprinus carpio, viz. common and koi carp, with cannibalism being higher in the latter. This finding substantiates the hypothesis that cannibalism is genetically controlled and therefore open to evolutionary change. It is concluded that cannibalism is adaptive in times of food limitation, but that it is merely a by-product of normal feeding behaviour when food is abundant. Since cannibalism is advantageous and thus adaptive, the question arises ai to whether selection is occurring at the individual or the population level (or both). It was concluded that it is acting at the individual level, and that any benefits accruing at the population level iv were simply the effect of the initial cause, viz. individual selection. One of the aims of this study was to determine whether cannibalistic tendencies in fish are influenced by differing life history style trajectories. Based on the results of this study it is hypothesized that cannibalism is an r-selected trait. wi th the understanding gained from the knowl edge of the fundamental principles governing cannibalism, certain recommendations for its control in fish culture could be made. It is, however, imperative that further intensive studies be carried out to understand more fully this complex subject. General "rules" for regulating cannibalism could be helpful for any given cannibalistic species. However, in considering the differing life-history styles of each species, it becomes evident that species-specific guidelines need to be worked out. Until then, any suggestions for cannibalistic control offered to the aquaculturist can only serve as unrefined tools.

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15

Yuen, Pui-sze. "Feasibility of total prohibition of fishing in marine protected areas of Hong Kong." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43784598.

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16

Situ, Yingyi. "Ichthyoplankton assemblage at Cape d'Aguilar seasonal variability and family composition /." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38993387.

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17

Baines, David Christian. "Tooth microwear in fishes." Thesis, University of Leicester, 2010. http://hdl.handle.net/2381/8753.

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The published articles, p. 149 onwards, are not available in the electronic version of this thesis due to copyright restrictions. The full version can be consulted at the University of Leicester Library.

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18

Turner, Jonathan Russell. "Vision in marine fishes." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528093.

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19

Kennon, Ronald Adam. "Effects of spatial and temporal variability of shoal habitat on stream fish assemblages in Chattahoochee tributaries, Alabama." Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/KENNON_RONALD_29.pdf.

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20

Mills, Lesley Judith. "Effects of endocrine-disrupting chemicals on fish reproduction and reproductive indicators /." View online ; access limited to URI, 2006. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3248238.

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21

Branson, Adam. "A comparison of fish assemblages utilizing estuarine and ocean surf habitats in southeastern North Carolina." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-2/bransona/adambranson.pdf.

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22

Spooner, Ashley. "The mercury contamination in fish and the subsequent public health effects." [Denver, Colo.] : Regis University, 2006. http://165.236.235.140/lib/ASpooner2007.pdf.

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Senior Honors thesis--Regis University, Denver, Colo., 2007.
"May 2006"--T.p. Date of submission on Certification of Authorship page: 4/16/07. Title from PDF title page (viewed on June 26, 2007). Includes bibliographical references.

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23

Piette, Randal R. "Effects of flow regulation due to hydroelectric project operation on the structure of fish communities in Wisconsin's large river systems /." Link to abstract, 2004. http://epapers.uwsp.edu/abstracts/2004/Piette.pdf.

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24

Tonello, Mark A. "Population structure and dynamics of alewives and spottail shiners in Indiana waters of Lake Michigan, 1984-1996." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1048392.

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The population dynamics of alewives Alosa pseudoharengus and spottail shiners Notropis hudsonius were investigated in Indiana waters of Lake Michigan from 1984-1996. Insights to population dynamics of both species were found by applying age and growth information to length-frequency distributions of index trawl catches within and between years. Both alewife and spottail shiner populations showed general increasing trends over the period, reaching peak levels in 1996. Interaction potential was examined for alewives, spottail shiners, and the yellow perch Perca flavescens, another important nearshore species. Trends in relative catches of these species were correlated to provide insight to possible interactions. There appears to be negative relationships between alewife and yellow perch populations, as well as between yellow perch and spottail shiner populations. No relationships were found between alewife and spottail shiner populations.
Department of Biology

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25

Cox-Rogers, Steven Frank. "Racial analysis of Skeena River steelhead trout (Salmo gairdneri) by scale pattern features." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24598.

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The feasibility of using freshwater and first marine year scale patterns to identify component stocks of steelhead trout (Salmo gairdneri) in the Skeena River was investigated. Scale samples and sex and size data were attained from adult steelhead originating from five Skeena River tributaries (Zymoetz, Kispiox, Morice-Bulkley, Babine, Sustut) over a series of different years. Adult scale samples were also collected from the 1984 incidental steelhead catch in the Area 4 commercial salmon fishery for potential stock classification purposes. Significant differences in scale pattern growth, age composition, and sizes at age were found between the five Skeena River steelhead stocks. Linear discriminant function analysis indicated that the five stocks could be classified to correct river of origin with between 45% and 62% average classification accuracy (range Zymoetz 29%-60%, Kispiox 35%-60%, Morice-Bulkley 44%-76%, Babine 54%-64%, Sustut 56%-72%) depending upon the classification model used. Juvenile morphometric analysis for three of the stocks (Kispiox, Morice-Bulkley, Zymoetz) indicated the presence of significant between stock differences in standardized body form. These results support the notion that Skeena River steelhead exist as quantifiably discrete stocks. Classifying the 1984 mixed stock commercial fishery catches to probable stock of origin indicated that distinct peaks of stock abundance and run-timing occur through the fishery. In general, Morice-Bulkley and Sustut River steelhead were predicted to be most abundant with run-timings during the earlier portions of the fishery. Kispiox, Babine, and Zymoetz River steelhead were predicted to be less abundant with later run-timings through the fishery. Potential commercial fishery impacts to steelhead are briefly discussed. These observations suggest that the technique of scale patterns is a feasible method for stock separation in Skeena River steelhead. Further study is required to clarify yearly variance in the technique and to better establish stock specific differences.
Science, Faculty of
Zoology, Department of
Graduate

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26

Pham, Cong Tri. "The ecology of fish larvae in Pumicestone Passage : an estuarine system in Southeast Queensland, Australia /." St. Lucia, Qld, 2000. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16437.pdf.

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27

Vine, Niall Gordon. "Towards the development of a protocol for the selection of probiotics in marine fish larviculture." Connect to this title online, 2004. http://eprints.ru.ac.za/196/.

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28

Wood, Stephen William. "Systematics of the macrourid fishes." Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/263146.

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The systematics of rattail fishes (Teleostei: Gadiformes, Macrouridae) is reexamined focussing on the Coryphaenoides group of genera, including Albatrossia, Lionurus, Chalinura and Nematonurus. The data matrix consists of 69 osteological characters based on personal observations, 17 characters, generally of the soft anatomy, from various published sources and 34 characters reported from peptide mapping of muscle-type lactate dehydrogenase. An evolutionary systematics of morphology requires, firstly, a historical concept of homology and secondly, a scientific basis for the recognition of patterns. Viewing the organism as a hierarchy of constraint, homology is a relationship of development constraint inherited by parts of organisms. Taxa are types, relationships of constraint inherited by organisms. If, from the morphological perspective, taxa are relationships not groups, conventional concepts of monophyly and related terms cannot apply to them. In practice they describe comparisons between trees. The creation/discovery of patterns is embedded in the practice of systematics and has its basis in the intelligent abilities of human beings. Morphology deals with the linguistic aspect of evolution, rather than with its dynamic genetic aspect. Dynamic and linguistic aspects are complementary yet incompatible. The scientific status of morphology is shown to rest on this principle of complementarity. Through cladistic analysis of a large number of published characters, I investigate the scenarios and relationships of gadiform fishes that have recently been proposed. The results of the rattail analysis are thus placed within the broader context of gadiform ecology and evolution. In cladistics, parsimony plays the role of Popper's-empirical concept of simplicity, as a method of estimating the hypothesis of highest empirical support. Assumptions are made about the likely pathways of evolution in the way the characters are coded. Original classifications of the Gadiformes and the Macrouridae are proposed. Within the gadiforms there is a general trend from jaw precision to jaw protrusion. An index of protrusion/precision shows a negative correlation with depth. Rattails show low values of the index indicating high jaw protrusion. However, within the family the trend is towards higher jaw precision, and the precision/protrusion index is positively correlated with maximum depth. The discovery of cartilage in the exoskeleton of rattail fishes was an unforeseen result of the method of preparation. In rattails alcian blue reveals hyaline cell cartilage at the margins of certain dermal elements where it is gradually replaced by bone.

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29

Vine, Niall Gordon. "Towards the development of a protocol for the selection of probiotics in marine fish larviculture." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1005175.

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Manipulation or control of the microbiological aquaculture environment has been identified as an important focus area for future hatchery development. Subsequently, alternatives to obtain control of the microbiological environment are being sought of which the field of probiotics appears highly promising. Probiotics are usually selected based on various in vitro characteristics, however, the methods used differ and are sometimes unsuccessful due to poor experimentation. The aim of this work is to contribute towards the development of a protocol for the in vitro screening of bacterial candidate probiotics for marine fish larviculture. To reduce the number of candidate probiotics to be tested in vivo, various in vitro experiments need to be conducted, each screening for a particular mode of action – antagonism towards pathogen through production of antimicrobial compounds, growth and attachment to fish intestinal mucus, and the production of other beneficial compounds such as vitamins, fatty-acids and digestive enzymes. A total of 108 bacteria species were isolated from the digestive tract of the adult common clownfish, Amphiprion percula to screen for potential probiotics to be used in clownfish larval rearing. The antagonistic compounds assay identified twelve isolates which showed antagonism towards two or more aquatic pathogens. This was followed by an in vitro test that involved growing the organisms in fish intestinal mucus and modeling their growth parameters. A ranking index (RI) was developed using the lag period (λ) and doubling time (td) of the organism, where (1over λ x td) x 100. Five candidate probionts (AP1-AP5) with varied growth parameters were used for further in vitro experiments. The attachment to mucus assay introduced a novel tool for quantifying competition for attachment sites between candidate probionts and pathogens on mucus. Candidate probiont Pseudoalteromonas AP5 reduced the attachment ability of Vibrio alginolyticus when added before the pathogen and partially out-competed the pathogen for attachment sites when added second. In vitro screening for the production of beneficial compounds tested the candidate probiotics’ ability to produce digestive enzymes - trypsin, lipase and alkaline phosphatase as well as carotenoids and vitamin C. Candidate probiont Pseudoalteromonas AP5 produced high levels of the enzymes (98.2, 34.1 and 91.3 mU product liberated.ml⁻¹, respectively) and contained carotenoids while Kocuria AP4 contained carotenoids but produced low quantities of enzymes (7.8, 0 and 59 mU product liberated.ml⁻¹, respectively). None of the candidate probiotics produced vitamin C. To eliminate potential pathogenic or toxic candidate probionts, Artemia nauplii were exposed to each candidate probiont and the percentage Artemia mortality after 24-hours was determined. Candidate probiont AP2 caused high mortality of Artemia nauplii (98.4%) and was excluded from further studies. Identification of candidate probionts AP3-AP5 was performed using 16S-rDNA molecular techniques and the bacteria were assigned the names Bacillus AP3, Kocuria AP4 and Pseudoalteromonas AP5, respectively. Two methods of larval probiont delivery were tested – attachment to Artemia, and in-water delivery. Attachment to Artemia was high for both Kocuria AP4 and Pseudoalteromonas AP5 (7.2 x10³ and 2.7x10⁴ bacteria.nauplius⁻¹, respectively) while the in-water viability experiment showed that Kocuria AP4 comprised 23.9% of the total culturable water microflora after 24 hours while Pseudoalteromonas AP5 contributed 100%. To validate the findings from the in vitro experiments, in vivo trials using clownfish larvae were performed. Of the four candidate probiotics tested, only Kocuria AP4 showed potential to increase larval survival. In vitro tests produced a better understanding of the possible mode of action and strategies of competition between bacteria, however, the number of criteria in which a candidate probiont is successful in vitro may not be the best predictor for its effectiveness in vivo. Commercial studies that reduce between-treatment variation are required to test predictions about the most suitable probiont or combinations thereof.

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30

Sugiura, Shozo H. "Development of low-pollution feeds for sustainable aquaculture /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/5298.

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31

Mbokane, Esau Mathews. "Metazoan parasites and health of selected cyprinids at Nwanedi-Luphephe dams." Thesis, University of Limpopo (Turfloop Campus), 2011. http://hdl.handle.net/10386/748.

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Thesis (M.SC. (Aquaculture)) --University of Limpopo, 2011
The present MSc dissertation emanates from seasonal surveys conducted by the fish parasitological group of the Department of Biodiversity and Aquaculture Research Unit of the University of Limpopo, Turfloop Campus. The first part of the present study was aimed at investigating the metazoan parasites of three cyprinids occurring in the Nwanedi-Luphephe Dams. The main purpose of it was to determine temporal changes in the intensity of infestation in terms of prevalence, mean intensity and abundance of parasite species parasitizing the cyprinids studied over a two year period. Ecological parameters including species host-specificity, seasonality, and gender preference and host size versus species intensity are discussed for each parasite. Altogether 152 specimens were examined for parasites and a total of 2 432 metazoan parasites of ten species were recorded. At the sampling site, all three hosts co-occurred, however, a substantial proportion of Barbus radiatus was collected from the perennial stream feeding one of the twindams. Fish were sampled by means of gill nets and electrofishing or seine netting in accordance with the habitat conditions. Hosts were killed and organs investigated for metazoan parasites. After collection of parasites, standard methods for processing individual parasites were followed. The results obtained revealed the following groups of parasites; monogeneans (ectoparasites) included Dactylogyrus spinicirrus, D. afrolongicornis afrolongicornis, D. afrolongicornis alberti, Afrodiplozoon polycotyleus, Gyrodactylus sp., and Dogielius sp. (all recorded from the gills); Crustacea, Dolops ranarum was found from the mouth cavity, gills and skin of Labeobarbus marequensis. Of these, only two specialists, both monogeneans, were found on Barbus trimaculatus namely, D. afrolongicornis afrolongicornis and D. afrolongicornis alberti. Based on morphology of the haptoral hard parts, these two species were almost similar to each other than to D. spinicirrus. The appreciable difference between D. afrolongicornis afrolongicornis and D. afrolongicornis alberti was mainly in the shape of the marginal bar. Both D. spinicirrus and A. polycotyleus were widely distributed and recorded on the gills of all hosts during all seasons. Both species were recorded for the first time on B. radiatus. Also, D. spinicirrus was recorded for the first time on the gills of B. trimaculatus. Based on comparison with the original material, the species could be identified to species level. These analyses provided sufficient evidence for restoration of Afrodiplozoon polycotyleus as a valid taxon. The existence of two species, Gyrodactylus sp. and Dogielius sp. were recorded for the first time on B. radiatus in South Africa, and this possibly represents new species. The endoparasites included the following groups: digeneans- Diplostomulum metacercariae from the eyes of Lb. marequensis, Ornithodiplostomum sp. and black spot (grubs) were recorded from B. trimaculatus. The latter was also recorded in the muscle of B. radiatus. Unidentified digenean cysts were recovered from the gills and in the body cavity of both Lb. marequensis and B. trimaculatus; nematodes were represented by Contracaecum larvae in the body cavity of both Lb. marequensis and B. trimaculatus; cestodes were represented by gryporynchid larvae from the intestine of B. radiatus. The general high prevalence and intensities of ectoparasites recorded is an indication that the Nwanedi-Luphephe Dams has a biotic mechanism which might have enabled it to sustain the growth rate of ectoparasite intra-population. There was no correlation between either fish length or condition factor and the number of parasites. The study indicated that the abundance of monogeneans is partly influenced by season and that of endoparasites was principally governed by the presence of intermediate hosts and definitive hosts. The second part of this dissertation dealt with the health status of Lb. marequensis. Fish health was assessed using condition-related indices including condition factor and a modified Health Assessment Index (HAI) and the associated Parasite Index (PI). The HAI was performed to determine and examine any macroscopic abnormalities regarding external features and internal organs. The purpose of combining the two indices was to use the infestation of the metazoan parasites found on and/or in Lb. marequensis to determine whether or not the environment they live in was healthy. Both indices together with the condition factor provided relatively simple and rapid indications of how well fish were coping in their environment. The HAI score varied amongst the four sampling seasons. The highest individual mean value was 63 in winter, followed by a score of 50 in autumn, while the lowest were 42 and 33 in summer and spring respectively. To authenticate the HAI and PI data, certain water quality variables were measured and are discussed in detail in this dissertation. The Nwanedi-Luphephe Dams are generally believed to have good water quality. This was supported in this study; conditions assessed in fish using the aforementioned indices did not differ greatly between seasons, nor did the conditions deviate appreciably from normality. The HAI values were low overall which signifies a healthy fish profile for the system. The present investigation showed the existence of differences in the occurrence of individual parasite to be linked to water temperature changes. Thus, seasonal changes do influence parasite developmental stages to a certain degree. Tested heavy and trace metals were within the permissible limits as provided by the Department of Water Affairs and Tourism (DWAF, 1996).

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32

Horton, Jonathan F. "Dynamic responses of a 20-ton capacity feed buoy in an open ocean environment." Restricted access (UM), 2008. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.

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These (M.S.)--University of New Hampshire, 2008.
Title from PDF title page. Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 58-59). Also issued in print.

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33

Winter, Brian D. "Determinate migratory behavior of steelhead (Oncorhynchus mykiss) parr. /." Thesis, Connect to this title online; UW restricted, 1992. http://hdl.handle.net/1773/5339.

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34

Bjorgo, Kimberly A. "Distributional ecology of Kanawha River fish." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4814.

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Thesis (Ph. D.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains vii, 195 p. : ill. (some col.), col. maps. Vita. Includes abstract. Includes bibliographical references.

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35

Fast, David E. "The behavior of salmonid alevins in response to changes in dissolved oxygen, velocity and light during incubation /." Thesis, Connect to this title online; UW restricted, 1987. http://hdl.handle.net/1773/5363.

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36

Smith, Jonathan Staunton. "The biology and ecology of Ponyfish (Leiognathidae) in the Gulf of Carpentaria, Northern Australia /." St. Lucia, Qld, 2000. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16109.pdf.

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Armstrong, Sharyn G. "Chemical analysis of nutritionally important components in temperate Australian fish /." [S.l. : s.n.], 1992. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030521.112132/index.html.

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38

van, der Walt Kerry-Ann. "Prioritising native fish populations for conservation using genetics in the Groot Marico catchment, North West Province, South Africa." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/69102.

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The Groot Marico catchment in the North West Province is a National Freshwater Ecosystem Priority Area (NFEPA) because it represents unique landscape features with unique biodiversity that are considered to be of special ecological significance. Three native freshwater species Amphilius uranoscopus, Chiloglanis pretoriae and Barbus motebensis, have high local conservation importance and B. motebensis is endemic to the catchment and is IUCN-listed as vulnerable. The main objective of this study is to contribute towards the effective conservation of these three species in the Groot Marico River system by assessing their genetic structure to determine whether tributary populations of the three species comprise of one genetic population or whether they are divided into genetically distinct subpopulations, in order to prioritise areas for conservation. The central null hypothesis was that there is no genetic differentiation between tributary populations (i.e., panmixia) of B. motebensis, A. uranoscopus and C. pretoriae in the Groot Marico catchment, North West Province. In total, 80 individuals per species were collected, targeting at least 10 individuals per population from a total of eight populations (seven tributaries and the Groot Marico main stem) and across the study area. Samples were collected by electrofishing and specimens were euthanized using an overdose of clove oil. A sample of muscle tissue was removed for genetic evaluation and the remainder of the specimens served as voucher specimens. For the genetic evaluation, mitochondrial (ND2, cyt b) and nuclear (S7) genes were used. Genetic techniques used were DNA extraction, polymerase chain reaction (PCR), purification and sequencing. From the 240 individuals collected, 123 sequences for B. motebensis, 111 sequences for A. uranoscopus and 103 sequences for C. pretoriae were analysed across all three genes. Statistical analysis included looking at cleaned sequences in order to obtain models using MODELTEST (version 3.06). Population structuring and phylogeographic analysis was performed in Arlequin (version 2000), TCS (version 1.2.1) and PAUP*. Results indicated that for B. motebensis the null hypothesis could be rejected as there were two distinct lineages (the Draai and Eastern lineages) that demonstrated significant divergence in both the ND2 and S7 genes, suggesting historical isolation. The low divergence in the mitochondrial cytochrome b gene (0% < D < 0.8%) suggests that this isolation is not very old and is probably not comparable to species level differentiation. The null hypothesis was also rejected for A. uranoscopus as there were also significant levels of differentiation between tributary populations resulting in the identification of two lineages (the Ribbok and Western lineages). However, for C. pretoriae, the null hypothesis could not be rejected as there was no genetic differentiation between tributary populations i.e., one panmictic population. Therefore, due to each species showing different genetic structuring within the tributary populations, more than one priority area for conservation needs to be implemented. These priority areas of conservation where therefore evaluated based on the current conservation status of the species (B. motebensis being vulnerable on the IUCN Red List), the number of Evolutionary Significant Units for each species and the overall genetic diversity of all three species in the Groot Marico catchment. In total, four tributary populations were conservation priorities areas, these were the Draai, Vanstraatens, Ribbok and Kaaloog tributaries. The Draai, Vanstraatens and Kaaloog tributaries were selected as priority areas for B. motebensis (B. motebensis is considered to be the most vulnerable of all three species). The Draai tributary was selected due to the B. motebensis population within the tributary showing isolation from the rest of the tributary populations. In order to conserve B. motebensis from the Southern lineage, the Vanstraatens and Kaaloog tributaries were selected. Reasons for selecting these two specific tributaries within the Southern lineage were that the Vanstraatens tributary had unique alleles (three Evolutionary Significant Units) for B. motebensis and the Kaaloog tributary had high genetic diversity (HD = 0.889, ND2 gene) when compared to the other tributary populations. The Ribbok and Vanstraatens tributaries were selected as priority areas for the conservation of A. uranoscopus. The Ribbok tributary was selected as it showed isolation from the rest of the tributary populations, as seen with the Draai tributary (B. motebensis) and the Vanstraatens tributary was selected to represent the Western lineage as it had the highest diversity for both genes (ND2 and S7). The Ribbok tributary has the highest prioritisation when compared to the Vanstraatens tributary. Chiloglanis pretoriae occurs within the Draai, Vanstraatens, Ribbok and Kaaloog tributaries, therefore by prioritising these tributaries for conservation, C. pretoriae will in turn be conserved.

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Kanyerere, Geoffrey Zantute. "Age, growth and yield-per-recruit analysis of ndunduma Diplotaxodon limnothrissa (Teleostei: Cichlidae), in the southeastern arm of Lake Malawi." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1005057.

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Diplotaxodon limnothrissa Turner (1995) is a widely distributed species occurring throughout Lake Malawi, extending from the surface to a depth of at least 220m. It is probably the most abundant cichlid in the lake with biomass estimates of around 87 000 tonnes in the pelagic zone alone. The species is exploited commercially in the southern part of the lake but since its inception the fishery has never been assessed. As such this study investigates some aspects of age and growth of the species besides applying a yield-per-recruit analysis to assess the status of the fishery. Analysis of sectioned sagittal otoliths revealed that D. limnothrissa is fast growing and relatively long-lived species, attaining ages in excess of 10 years. Growth in length was rapid in immature fish, with fish attaining almost half of their maximum size within their first year. Le ngth-at-age was described by the von Bertalanffy growth model with combined-sex growth described as Lt = 211.21(1-exp(- 0.24(t+1.36))) mm TL. Total, natural and fishing mortalities were estimated at 0.76 yr⁻¹, 0.31 yr⁻¹ and 0.45 yr⁻¹ respectively. Per-recruit analysis indicated that the D. limnothrissa stock in the southeast arm of the lake is fully exploited as indicated by the current spawner biomass-per-recruit ratios of 31-55% (SB/R)F=0. Modelling indicated that the current age-at-capture (2.67 years) is lower than the age at which yield is optimised (> 5 years) based on the F₀·₁ harvesting strategy. It is, therefore, recommended that the age-at-capture should be increased from 2.67 to 5 years to optimise yield.

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Fraser, Helen M. "Do fish predators in the North Sea live beyond their means is prey production sufficient to meet consumption? /." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=24693.

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41

Wraith, James A. "Assessing reef fish assemblages in a temperate marine park using baited remote underwater video." School of Biological Sciences, 2007. http://ro.uow.edu.au/theses/12.

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Baited remote underwater video (BRUV) is becoming an increasing popular tool for examining reef fish assemblages in depths less than 100m. This sampling technique is relatively new in the literature and several gaps remain to be filled. Scientists using this technique have selected bait based on results from trapping experiments. Therefore the first objective of the study was to compare commonly used baits and test if different fish species and fish assemblages were recorded. I planned to apply results from the first study towards further research using BRUV. Management at Jervis Bay Marine Park, located in southeast Australia, have applied a strategy to protect a comprehensive and representative sample of local habitats and associated flora and fauna. In doing so, sanctuary “no take” zones have been put in place. Surprisingly, there are no patch reefs afforded this protection. My second objective was to provide the Jervis Bay Marine Park management with baseline data on deep patch reef locations and to draw comparisons between deep patch, deep coastal, and shallow coastal reefs. I compared three different baits (pilchard, abalone, and urchin) at three locations in two separate years. A total of 63 “drops” (30 min recordings) were conducted in two years and a total of 47 species were recorded. There were no differences in the diversity and abundance of fish recorded while baited with pilchard and abalone. In contrast, in the second year of sampling I detected a greater species richness and abundance using pilchard, compared to urchin, at most locations (p<0.05). The two most speciose families recorded in the study were Labridae and Monacanthidae. These families, as well as several individual fish species, were examined but there were no significant differences in their relative abundance among bait treatments. Additionally, in the second year of sampling I detected differences in H′ and time of first arrival among locations (p<0.05). Surprisingly, large differences between the baits were greatly reduced at one location - Plantation Point. I interpret this finding as there being a high density of fish at Plantation Point that masks the differences in the attraction of these baits. I concluded that as the behaviour and structure of the fish assemblage can vary in space, pilchard was the best choice of bait for consistently detecting species richness and abundance. A total of 144 BRUV “drops” (30 min recordings) in 9 locations in 2005 and 2006 were completed in the second study. The composition of fish assemblage at shallow and deep water habitats was different (p<0.05). Indeed, depth related differences for temperate reef fish are well documented and my findings emphasise the need for the Marine Park management to maintain protection of reef habitats across abroad range of depths. I did not detect any differences in the composition of the fish assemblage or the relative abundance of fish between the two deep habitats (p>0.05), although the presence of several rarely encountered species including Bodianus unimaculatus, Coris sandageri, Meuschenia scaber, Caesioperca lepidoptera, and Eubalichthys mosaicus were recorded in the deep patch reef habitat. I concluded that the inclusion of the deep habitat in the sanctuary zoning plan is important for protecting fish biodiversity. By generating permanent baseline data, this study aims to assist Marine Park management in making sound decisions on future zoning plans.

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42

Powell, Frank. "Effects of salinity on eggs and yolk-sac larvae of Atlantic cod, Atlantic halibut, haddock and winter flounder." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0004/MQ42426.pdf.

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43

Walker, Jennifer L. "Parasites of catostomid fishes from navigation pools 8 and 9 of the upper Mississippi River (Iowa, Minnesota, Wisconsin) and the lower Missouri National Recreational River (Nebraska, South Dakota) /." Connect to online version of: Parasites of catostomid fishes from navigation pools 8 and 9 of the upper Mississippi River, 2007. http://digital.library.wisc.edu/1793/21447.

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44

Miller, Jessica Adele. "Local and regional patterns of transport, dispersal, and exchange in coastal fishes /." view abstract or download file of text, 2004. http://wwwlib.umi.com/cr/uoregon/fullcit?p3136435.

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Thesis (Ph. D.)--University of Oregon, 2004.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 215-240). Also available for download via the World Wide Web; free to University of Oregon users.

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45

O'Connell, Bronwyn Anne. "Home range dynamics of spotted grunter, pomadasys commersonnii, in a South African intermittently open estuary." Thesis, Rhodes University, 2008. http://eprints.ru.ac.za/1289/.

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46

Vogel, Runhild Solveig. "Die Aussenfischereibeziehungen der Europäischen Gemeinschaft : Schutz und Bewirtschaftung kommerziell genutzter Fischbestände in der Europäischen Gemeinschaft /." Frankfurt, M. ; New York, NY : Lang, 2009. http://d-nb.info/995506582/04.

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47

Stefferud, Jerome A., and John N. Rinne. "Sustainability of Fishes in Desert River: Preliminary Observations on the Roles of Streamflow and Introduced Fishes." Arizona-Nevada Academy of Science, 1995. http://hdl.handle.net/10150/296454.

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From the Proceedings of the 1995 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 22, 1995, Northern Arizona University, Flagstaff, Arizona

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Geange, Shane Wallace. "An evaluation of prior residency and habitat effects on the persistence of settling reef fishes : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Doctor of Philosophy in Marine Biology /." ResearchArchive@Victoria e-Thesis, 2010. http://hdl.handle.net/10063/1169.

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49

Wiff, Rodrigo. "Predicting food consumption and production in fish populations : allometric scaling and size-structured models." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/935.

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Life-history traits in fish populations are highly correlated. A subset of these correlations are called allometric scaling, they refer to biological processes which can be described using body size as independent variable. Particularly, allometric scaling related with food consumption (Q) and biomass production (P) has gained the attention of ecologists for several decades. This thesis proposes a quantitative framework for food consumption, which allows both the identification of the mechanisms underlying the allometric scaling for Q and the development of a predictive model for consumption to biomass ratio (Q/B) in fish populations. This thesis is based on the fact that food consumption can be inferred from first principles underlying the von Bertalanffy growth model. In addition, it has been noticed in the literature that biomass production and food consumption show similar allometric scaling dependence, therefore, both can be derived from these first principles. Thus, a similar quantitative framework was used to produce models for P/B in fish populations. Once functional forms for production and food consumption were identified, a third model was developed for the ratio between production and consumption (P/Q). This ratio is usually named ecological efficiency because it determines how efficiently a population can transform ingested food into biomass. Several authors have noticed that P/Q remains invariant (independent of body size) across species. From a theoretical point of view, the results presented here allow the first quantitative explanation for the existence of the allometric scaling for Q/B and the invariance of P/Q across fish species. These results, together with the explanation for allometry in P/B reported in the literature, suggest that the regular across-species pattern for the trio {P/B,Q/B,P/Q} can be explained by basic principles that underpin life-history in fish populations. This quantitative framework for the trio {P/B,Q/B,P/Q} is based on an explicit dependence with body size, which simplifies the estimation of these quantities. Model complexity depends, in part, on which data are available. Models were applied to real data from commercially important species fished in Chile. Statistical properties of the new models were evaluated by an intensive resampling approach. The simplest possible model for the trio {P/B,Q/B,P/Q} rests on the assumption of a stable age distribution. These quantities have a key importance in ecosystem modelling because they determine population energetics in terms of food intake by predation and the transformation of this energy into population biomass of predators. Application of the new models produces results which were comparable to those given by standard methods. This thesis is a result of multidisciplinary research which attempts to make a contribution to the understanding of the mechanisms underlying the allometric scaling of food consumption and production in fish populations. It proposes models for the trio {P/B,Q/B,P/Q} and thus, has the potential to be widely applicable in fisheries science.

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Boyd, James W. "Effects of water temperature and angling on mortality of salmonids in Montana streams." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/boyd/BoydJ0808.pdf.

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In Montana, angling closures are used to protect salmonids from the deleterious impacts of angling at elevated water temperatures (23Â°C). Catch-and-release angling (CR) studies have reported high levels (30-40%) of salmonid mortality at water temperatures >20Â°C, but few studies assess CR mortality of salmonids at water temperatures observed in Montana streams during mid-summer (23Â°C). The primary objective of this study was to measure CR mortality of rainbow trout, brown trout, and mountain whitefish in three water temperature treatments; when daily maximum water temperatures were cool (<20Â°C), warm (20 to 22.9Â°C), and hot (23Â°C). A secondary objective was to assess CR mortality of salmonids angled in morning and evening within water temperature treatments. Based on the literature, mortality of salmonids was predicted to be >30% within the hot treatment and higher in evening than morning. Angling (fly-fishing only) occurred in the Gallatin and Smith rivers. All angled fish were confined to in-stream holding cages and monitored for mortality for 72 h. Mortality of rainbow trout Oncorhynchus mykiss increased to 9% and 16% in warm and hot treatments, respectively. Mortality of brown trout Salmo trutta was (4%) in the hot treatment in the Smith River. Mountain whitefish Prosopium williamsoni had increased mortality in the warm (20%) and hot (28%) treatments in the Smith River. No mortality for any species occurred in either river when water temperatures were <20Â°C. Mortality of rainbow trout angled in evening was higher than morning in the warm (14%) and hot (16%) treatments in the Smith River. Laboratory results indicated rainbow trout stressed in evening had higher mortality (7%) than those stressed in morning (0%). Angler catch rates were lower for most species in evening than morning angling events; however, catch rates remained high (0.7 fish/h) in several evening angling events. Study results indicate that salmonid mortality rates associated with catch-and-release fly-fishing are higher at elevated (>or equal to 23Â°C) water temperatures. Although there was a relationship between elevated water temperature and salmonid mortality, most of the mortality estimates were well below the 30% mortality that was predicted.

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