vi, 50 leaves : ill. ; 29 cm Typescript. (Another copy on microfilm is located in Archives) Thesis (M.S.)--University of Oregon Vita Bibliography: leaves 46-50

No description available.

Made available in DSpace on 2014-06-11T19:28:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-04Bitstream added on 2014-06-13T20:58:12Z : No. of bitstreams: 1 ribeiro_rr_me_botfmvz.pdf: 370485 bytes, checksum: 1c93b70938565887e570cdb0eedc44ae (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A influência de fatores ambientais, o manejo alimentar e a qualidade da ração são determinantes na formação de reprodutores e no manejo reprodutivo, podendo influenciar nos custos de insumos e na qualidade dos alevinos produzidos. O presente estudo teve como finalidade avaliar o desenvolvimento gonadal do Rhamdia quelen em tanque-rede até a primeira maturação sexual com diferentes níveis de proteína e frequências alimentares, verificando a influência desta fase no crescimento dos peixes cultivados. O experimento foi realizado de agosto a novembro de 2011 em viveiro escavado com renovação diária de 5%. O delineamento foi o inteiramente casualizado no modelo fatorial, com duas frequências alimentares (3 e 24 vezes/dia) no período noturno e com dois níveis de proteína (28 e 32% PB) com ingredientes de origem vegetal. Foram utilizados 864 jundiás com peso médio de 45 gramas, distribuídos em 24 tanques-rede. A maturação gonadal avançou à medida que o fotoperíodo e a temperatura aumentaram do mês agosto até novembro. As fêmeas alcançaram sua primeira maturação sexual com 72,6 g (±18,4) e comprimento de 20,2 cm (±2,1) e os machos alcançaram sua primeira maturação sexual com 70,3 g (±25,8) e comprimento de 19,5 cm (±1,9). A frequência alimentar influenciou na maturação sexual de fêmeas de Rhamdia quelen / The influence of environmental factors, feeding management and feed quality are crucial in the establishment of breeding and reproductive management, it can influence the costs and quality of fingerlings produced. The present study was to evaluate the development of gonadal of Rhamdia quelen raised in cages until the first maturity with different levels of protein and feeding frequency, and the influence of this phase on the growth. The experiment was conducted from August to November 2011 in earth pond with water daily renewal of 5%. The design was completely randomized in factorial design with two feeding frequencies (3 and 24 times / day) at night and two protein levels (28 and 32% CP) with ingredients of plant origin. We used 864 silver catfish with an average weight of 45 grams, distributed in 24 cages. The maturation developed as the photoperiod and temperature increased during the months August to November. The females reach their sexual maturity with 72.6 g (± 18.4) and length of 20.2 cm (± 2.1) and males reached their sexual maturity with 70.3 g (± 25.8) and length of 19.5 cm (± 1.9). The sexual maturation of Rhamdia quelen female was influenced by feeding frequency

Orientador: Francisco Langeani Neto / Coorientador: Heraldo A. Britski / Coorientador: Márcio C. Chiachio / Banca: Roberto Esser dos Reis / Banca: Marcelo Ribeiro de Britto / Resumo: Pseudotothyris Britski & Garavello, 1984 é um gênero de cascudinhos pequenos da subfamília Hypoptopomatinae que conta com duas espécies válidas, P. obtusa e P. janeirensis. O gênero tem distribuição somente por bacias litorâneas do sul e sudeste do Brasil entre os estados do Rio de Janeiro e Santa Catarina. Schaefer (1991), em uma análise filogenética da subfamília Hypoptopomatinae, afirma não haver nenhum caráter diagnóstico unicamente derivado para Pseudotothyris, questionando sua validade taxonômica e sugerindo uma análise comparativa mais detalhada com os demais hipoptopomatíneos a fim de se determinar, se existirem, caracteres diagnósticos exclusivos para o gênero. Apesar dos inúmeros trabalhos posteriormente realizados sobre as relações filogenéticas da subfamília, nenhum deles incluiu as duas espécies válidas para o gênero. Com base no exposto, o presente trabalho realizou a análise filogenética e a revisão taxonômica do gênero a fim de avaliar sua composição específica, seu monofiletismo e o relacionamento filogenético entre suas espécies e delas com os demais Hypoptopomatinae. Para a análise filogenética foi realizado um estudo a partir de 108 caracteres observados para 49 táxons terminais, incluindo membros de Loricariinae, Hypostominae, Neoplecostominae e Hypoptopomatinae. Os resultados corroboram o monofiletismo do gênero, que é suportado por duas sinapomorfias não ambíguas: espinho neural central da vértebra 8 bem desenvolvido, alcançando pelo menos metade do tamanho do espinho neural central da vértebra 7; e odontódeos da margem anterior do focinho muito desenvolvidos apenas na região dorsal. Este último estado de caráter constituindo uma sinapomorfia exclusiva para o gênero dentro de Hypoptopomatinae. Assim como esperado e já sugerido... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Pseudotothyris Britski & Garavello, 1984 is a genus of small catfishes of Hypoptopomatinae with two species, P. obtusa and P. janeirensis. The genus occurs only in coastal basins in southern and southeastern Brazil, between Rio de Janeiro and Santa Catarina States. Schaefer (1991), in a phylogenetic analysis of the subfamily Hypoptopomatinae, did not found any uniquely derived unreversed character which diagnoses Pseudotothyris, and questioned the taxonomic validity of the genus, suggesting that a more detail comparative analysis is need to find exclusive diagnostic characters to the genus. Despite numerous studies about Hypoptopomatinae relationships performed later, no one of them included the two valid species of the genus. Based on this, the present study aims to perform the phylogenetic analysis and taxonomic revision of the genus, evaluating its specific composition, its monophyly, and the phylogenetic relationship within the genus and among the genus and other Hypoptopomatinae genera. Phylogenetic analysis was performed with 108 characters observed to 49 terminal taxa, including members of the Loricariinae, Hypostominae, Neoplecostominae, and Hypoptopomatinae. The results corroborated the monophyly of the genus that is supported by two unambiguous synapomorphies: central neural spine of eighth vertebra well developed, reaching at least half of the size of the central spine of the seventh vertebra; and anterior snout odontodes well developed only on dorsal region. Among the Hypoptopomatinae, this last character state is an exclusive synapomorphy for the genus. As expected and already suggested by other authors, Pseudotothyris is recovered as sister group of Otothyris, another genus that occurs in coastal drainages. As result of the taxonomic revision, we present... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:30:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-05-08Bitstream added on 2014-06-13T20:40:03Z : No. of bitstreams: 1 goncalves_cs_me_rcla.pdf: 1337384 bytes, checksum: 94cd3ab8a80a89526260a33dfb24ee7a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Estudos sobre alimentação natural de peixes contribuem para o conhecimento básico da biologia das espécies, compreensão da organização trófica do ecossistema e conhecimento das interações entre as espécies. O presente estudo visou estudar a biologia alimentar da ictiofauna na área de influência do reservatório da usina Mogi Guaçu e nas lagoas marginais naturais da Estação Ecológica (fazenda Campininha), município de Mogi Guaçu-SP, com o intuito de responder as seguintes questões: (1) quais recursos alimentares as espécies estão utilizando? (2) existe alguma preferência alimentar para as espécies? (3) ocorrem alterações sazonais na dieta das espécies? Para a captura dos peixes, foram utilizadas redes de espera, puçá e armadilhas do tipo covo. Foram capturados 2341 exemplares de 41 espécies pertencentes a cinco ordens e 15 famílias. A ictiofauna nos ambientes estudados foi composta por peixes típicos da bacia do alto Paraná indicando uma condição que, embora alterada, apresenta espécies essencialmente nativas desta região. Foram analisados 370 estômagos provenientes de 1900 exemplares de peixes pertencentes a 14 espécies nos dois ambientes. Entre os itens consumidos pelos peixes, detritos e insetos (fragmentos) foram os que mais contribuíram para a alimentação das espécies no reservatório e nas lagoas marginais, respectivamente. Verificou-se que a dieta das espécies no reservatório e nas lagoas marginais foi significativamente correlacionada entre os períodos seco e chuvoso não ocorrendo, portanto, alterações sazonais. Os itens de origem autóctone tiveram uma participação maior na dieta das espécies, incluindo algas, insetos aquáticos e detritos entre os mais freqüentes. Foram determinadas cinco guildas tróficas para as 17 espécies analisadas. No reservatório os curimatídeos compuseram a guilda... / Studies involving fishes natural feeding habits increases the knowledge about species biology, understanding the trophic structure and species interaction. This work was conducted to study the feeding biology of fishes from Mogi Guaçu reservoir and some oxbow lakes from a protected area known by fazenda Campininha (Mogi Guaçu municipality), to answer the following questions: (1) which food resources fishes are using? (2) is there any food resource preferred for them? (3) seasonal alterations occur in fishes diets? Fishes were sampled using simple gillnets with different meshes sizes and traps. We captured 2341 fishes from 41 species belonging five orders and 15 families. The fish fauna composition revealed typical species from high Paraná river system indicating the presence of native species although the human alterations in the region. We analyzed 370 stomachs from 1900 individuals (14 species from both areas). They consumed mostly detritus and insects (fragments). Fishes diet on reservoir and oxbow lakes were significantly correlated between the seasons and no changes were observed. The majority items consumed were from autochthonous origin, including algae, aquatic insects and detritus that appeared frequently. Five trophic guilds were determined to the 17 species sampled. Curimatidae were the most abundant species corresponding to detritivorous fishes, followed by omnivorous, invertivorous, piscivorous and herbivorous fishes. Four trophic guilds were found in oxbow lakes where the invertivorous fishes were the most abundant (Hoplosternum littorale, Hyphessobrycon bifasciatus and Hyphessobrycon eques), followed by detritivorous, omnivorous and piscivorous fishes. The frequencies obtained from stomach repletion, fat accumulation and gonadal maturation degrees were related with fish's conditions.

The importance of the cichlid teleost Tilapia mossambica as a protein source, coupled with its remarkable adaptability, has resulted in its introduction into many water systems throughout the tropical, sub-tropical and even temperate regions of the world. However, its successful exploitation of these waters is dependent very largely upon the value of minimum temperatures and their duration. For e.g. Long et al (1961) has drawn attention to the tremendous mortalities of T. mossambica that occur in shallow water bodies during the precipitous temperature decreases that accompany the winter monsoons in Vietnam and other eastern countries, even at temperatures as high as 14 or 16º C. Coehe (1967) does not recommend stocking with T. mossambica where temperatures are not above 14º C all the time. Ailanson et al (1962) conclude, after an experimental study, that low temperatures (13º C or lower) in South African highveld dams in winter are certainly an important factor in the extensive mortalities of T. mossambica that have been reported from these dams. Jubb (1961) also reports that this species is often killed during a severe winter in Rhodesia. Intro., p.1.

This study was prompted by the need to remedy the situation that existed with respect to the poor status of our knowledge regarding the ichthyoplankton assemblage of the nearshore region along the south-east Cape coast of South Africa. The first chapter provides a brief introduction to the field of ichthyoplankton research and includes a summary of the status of research in southern Africa and an explanation of early life history terminology. The selection of all sample sites, times and strategies is also outlined. The study area along the south-east Cape coast with respect to its location, climate and physical oceanography is described in the second chapter, as is the gear used, bongo nets and an RMT1x6. A sampling protocol for the use of bongos from a small ski-boat, and the RMT from the research vessels, and for the handling and processing of samples was established. The selection of Middlebank as the main monthly sampling site within the Tsitsikamma National Park (TNP) was based on taxonomic diversity as well as logistical and safety constraints. The effect of mesh size and time of sampling with bongo nets on the catchability of ichthyoplankton was investigated in chapter three. Most data was accumulated during Sea Fisheries research cruises, with additional collections coming from the National Parks vessel. Although the differences were not significant, the 505 μ mesh nets captured larger larvae, with catches comprising higher percentages of flexion and postflexion larvae. Larval concentration and size were consistently greater in samples from periods of reduced light intensity, but significant differences were the exception. It was decided that sampling with 505 μ mesh nets during daylight would provide a representative sample of the available ichthyoplankton assemblage, while at the same time being the most practical and least time consuming with respect to handling, clogging and backflushing. In chapter four, the early life history stages of thiny of the seventy-five taxa sampled are described, reflecting the paucity of information which existed on the ichthyoplankton of the nearshore zone in the south-east Cape. These descriptions are seen as an important contribution towards any future research efforts in the region, but as many of these descriptions are based on few or single specimens, it is realised that the description of egg and larval stages will be an ongoing process. Based upon the data collected during this study, an ichthyoplankton species checklist was established in chapter five. Seventy-five taxa of fish larvae were identified to either family, genus or species level. A number of squid para-larvae were also encountered. Similarities and discrepancies with a previous survey in the region are presented. The temporal distribution of eggs and larvae between August 1993 and October 1996 was established, and the spatial distribution of ichthyoplankton along an offshore transect was determined between January 1995 and May 1996. Only 7 species from Middlebank and twelve from all stations combined displayed seasonal trends, with most of these being prevalent during winter months. Egg production, both over Middlebank and from all stations combined, appeared to be consistent, with no seasonal trends. Based upon the results from the offshore transect samples, it would appear that a single ichthyoplankton assemblage exists from Storms River out to fifteen nautical miles. Although a variety of statistical methods were applied to the data during this study, low egg and larval concentrations and a low sampling frequency meant that results had to be interpreted carefully. Chapter six describes the preliminary investigation into the vertical distribution of eggs and larvae. During two research cruises, discrete depth sampling using an RMT1x6 net was performed, with the majority of samples being accompanied by physical data provided by a CTD rosette sampler. No definite patterns could be seen as larval concentrations were low, and the short time scale did not allow for the identification of any diel migratory patterns. The relationship between total larvae and the physical environment was poor. The only possible relationship was that between plankton volume and total egg and total larval concentrations. The TNP may play an important role in the conservation of reef fish and the seeding of nearby fishing grounds through the export of pelagic eggs and larvae. Chapter seven describes a preliminary investigation into the dispersal potential of ichthyoplankton from the TNP. Based upon longshore currents determined from drogues, ADCP vectors and current meter readings, it was clear that if larvae were passive drifters, the potential for their dispersal from the TNP did exist. This pilot study showed that future work should concentrate not only on the oceanographic aspects, but on behavioural aspects of larvae which may enhance or retard dispersal. In the final discussion, it is emphasised that while this study went a long way to increasing our knowledge of the nearshore ichthyoplankton community, the true picture of the temporal and spatial dynamics of the species assemblage may only be revealed once more intensive sampling has been performed. The resolution of the early life history stages of the sparids and the identification of eggs to species level are seen as priorities for the near future. A complete species checklist for the TNP is provided based upon previous surveys (both on adult and larval fishes), this work and personal observations. A total of 171 species of fish from 70 families were identified, illustrating that the eggs and larvae of many species in the TNP have yet to be sampled. A brief description of the collaborative effort which is envisaged for the TNP over the next few years is provided.

D.Sc. (Zoology) / Please refer to full text to view abstract

This is an account of some aspects of the ecology of the eastern Cape rocky, Sandelia bainsii Castelnau in the Tyume river in the eastern Cape. Previous unpublished work carried out by the Zoology Department of the University of Fort Hare in the mid-seventies indicated that the species was rare in the Tyume river. Because of its uncertain conservation status, its restricted geographic distribution and the lack of information on its biology, demography, feeding and reproductive biology were studied. The species occurs in the upper, middle and lower reaches of the Tyume river and is common in rocky , shallow habitats in the middle reaches of the system. The most important threats to the survival of S. bainsii appear to be habitat alteration and alien species. The presence of these threats and the small size of the population suggest that the species may be vulnerable to local extinction. As the total range of the species extends to only a few rivers in the eastern Cape, the species might face extinction if these threats are faced throughout its range. A detailed study on the autecology of S. bainsii was therefore carried out in order to provide a basis for rational conservation and management of the remaining populations of the species.The age structure and the growth rate of S. bainsii was determined using checks on scales and otoliths. Males grow faster and reach a larger size than females. The maximum length of S. bainsii is compared to that of other anabantids. The longevity of males is 5 years and that of females 3 years. Food preferences were determined by three different methods and the indices of relative importance of food items calculated for different length groups and seasons. S. bainsii was found to be an euryphagous and opportunistic predator whose diet consists largely of insects. A considerable overlap was found between the diet of S. bainsii and that of the two alien species, Salmo gairdneri and Micropterus salmoides which indicates a possibility of competition for food. Mark and recapture experiments showed that S. bainsii is a "sedentary " species which is unlikely to be seriously affected by man-made barriers to fish migration, such as weirs. The species reaches maturity during its second growing season (males 80 - 89mm and females 60 - 69mm) and the length at maturity is related to the modal length of males and females. A large proportion of the fish are thus mature at any given time. The fish spawn repeatedly during the summer breeding season, October to February resulting in near continuous recruitment. The possible adaptive value of this habit is discussed. An attempt is made to evaluate the life history style of S. bainsii in terms of the theory of r - and K- selection and altricial and precocial life history styles

The aim of this study was to improve the rearing of common clownfish Amphiprion percula, by weaning juveniles from a live feed to a formulated feed as early as possible, while still maintaining good growth and survival. The growth response of A. percula to a formulated dry feed was initially investigated. There was no difference in growth rate of juveniles fed a formulated feed, and the formulated feed supplemented with either Artemia or a Donax serra / Penaeus indicus combination. Amphiprion percula readily consumed the formulated feed, and the fishmeal/casein combination appeared an acceptable protein source. As the amount of protein included in a diet can have a profound effect on growth, the optimal dietary protein level for juvenile A. percula was investigated by feeding semipurified diets containing graded levels of protein, ranging from 40-65%. There was no difference in the growth rates of juveniles fed the various diets, however all diets promoted good growth with an average weight gain of 419%, and thus for the purposes of this study the diet formulation was deemed adequate. The histological study of the digestive system of larval A. percula revealed that the alimentary canal was advanced at hatching and that larvae start exogenous feeding immediately. Three days after hatch (DAH) the yolk sac is completely absorbed. In the hind-gut epithelium of 5-day-old larvae small supranuclear inclusion vacuoles appear, suggesting pinocytotic digestion, and by 7 DAH gastric glands are established in the epithelium of the stomach. Nine DAH supranuclear inclusion vacuoles appear in the epithelium of the mid-gut, indicating extracellular digestion and absorption across the lumen. As pinocytotic digestion of protein is less efficient than extracellular digestion, especially in the case of formulated feeds, it was hypothesised that the digestive system of A. percula could only effectively digest formulated feeds 9 DAH onwards. The two weaning experiments designed to test this hypothesis revealed that A. percula was able to utilise the formulated feed, without reduction in survival, from 7 DAH onwards. However, in terms of growth, the optimal time to wean juveniles from the live feed to the formulated dry feed was between 15 to 20 DAH. As A. percula accept a formulated feed and can benefit nutritionally from it, the dependence of larvae and juveniles on live feed can be reduced. This study has shown that the rearing of A. percula can been simplified and improved by weaning from 7 DAH with no reduction in survival, and from 15 to 20 DAH with no reduction in growth.