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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.

Limnological conditions in lakes of the Skeena drainage, British Columbia, have been examined to ascertain what factors may be restricting the distribution and/or abundance of the Eastern and Rooky Mountain whitefishes. The Eastern whitefish is known to be in only four Skeena lakes, and the Rocky Mountain whitefish in all Skeena lakes which have been investigated. It is probable that the Eastern whitefish has not entered other Skeena lakes because the lake conditions are not suitable for its establishment. Such conditions are mainly warm waters, shallow depths, and small area; and are sometimes the heavy silting of the water, and the resultant poor food supply. It is not numerous in any of the four lakes, probably because of the relative poor abundance of bottom food organisms, particularly in the absence of such organisms as the amphipod Pontoporeia. Conditions are apparently most favourable for Eastern whitefish in oligotrophia lakes. Rocky Mountain whitefish appear to favour eutrophic lakes, and are most abundant in lakes where a good supply of bottom food is assured by the absence of such potential competitors as the Peamouth chub and Squawfish. There is no evidence of any heavy predation on either of the two whitefish. It is improbable that any physical barrier has limited the distribution of these fish. / Science, Faculty of / Zoology, Department of / Graduate

The Yazoo River Basin of Mississippi includes several rivers and hundreds of floodplain lakes within an area greatly impacted by agriculture. I studied 17 of these lakes distributed over the lower half of the Yazoo River Basin to document fish assemblages and limnological patterns and to identify environmental variables that might influence these assemblages. Potential connectivity of the lake to parent river and wetland-lake area ratio in the watershed were related to the limnological conditions and fish communities. Lakes with greater potential connectivity tended to be deeper and had greater specific conductance and greater fish species richness including more riverine species. Conversely, as the potential connectivity decreased, lakes were shallower, had greater chlorophyll-a fluorescence, wetland-lake area ratio, and a less speciose lacustrine fish community. Species richness and assemblage composition of riverine species were related directly to potential connectivity. Lacustrine species assemblages were linked to wetland-lake area ratio and turbidity.

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A glance at a large scale map of Labrador-Ungava brings to the forefront the fact that a myriad of lakes abound in the area. Schefferville, Quebec, the site of the McGill Sub-Arctic Research Laboratory and of the field work included in this thesis, is in an extremely advantageous location for the study of lakes, both large and small, for besides being in a formerly glaciated area, it is located on folded sedimentaries surrounded by the Canadian Shield. [...]

Thesis (Ph. D.)--Miami University, Dept. of Geology, 2007. / Title from second page of PDF document. Includes bibliographical references (p. 192-199).

Thesis (M.S.)--University of Chicago, 1915. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 129-134).