Dissertações em Ecologia Aquática e Pesca (Mestrado) - PPGEAP/NEAP
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/3479
O Mestrado Acadêmico iniciou em 2007 e pertence ao Programa de Pós-Graduação em Ecologia Aquática e Pesca (PPGEAP) do Núcleo de Ecologia Aquática e Pesca da Amazônia (NEAP) da Universidade Federal do Pará (UFPA).
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Navegando Dissertações em Ecologia Aquática e Pesca (Mestrado) - PPGEAP/NEAP por Orientadores "NAHUM, Victoria Judith Isaac"
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Item Acesso aberto (Open Access) Biologia e ecologia trófica de Hemiodus unimaculatus (Bloch, 1794) (Characiformes: Hemiodontidae) no Rio Araguari, na área de influência da Usina Hidrelétrica Coaracy Nunes, Amapá, Brasil(Universidade Federal do Pará, 2012-04-25) TRINDADE, Paulo Arthur de Abreu; NAHUM, Victoria Judith Isaac; http://lattes.cnpq.br/3696530797888724This research aims to contribute to the knowledge of biology and trophic ecology of the species H. unimaculatus in Araguari river, in the influence area hydropower Coaracy Nunes, Amapá, Brazil. The study region corresponds to a portion of the river basin Araguari. Samples were collected bimonthly from May 2009 to July 2010. Batteries were used for mesh networks (2, 2.5, 3, 4, 5, 6, cm between opposite knots with 10 m x 1.5 m in height) and casting net (15 and 20 mm). The gillnets were exposed during 17 h, with inspects every 3h. The specimens collected were kept on ice and preserved in 10% formalin. They were weighed (Total Weight) and measured (Total Length). Sex was identified from the macroscopic analysis of gonads, which were weighed and preserved in 10% formalin. The stomachs were weighed and preserved in 70% alcohol. The environment was characterized by the multivariate analyzes. The length structure of the population, length-weight relationship, sex ratio, relative abundance and biomass were evaluated. The location and time of reproduction, size at first maturation and spawning type, were also studied. The trophic ecology was evaluated by feeding activity and content organic matter. Food items were analyzed by the methods of frequency of occurrence, degree of food preference and the feendig index. The results showed that the area downstream of the dam and lake area was greater transparency of the water in the reservoir depth and predominant amount was larger values of pH. The average length was 193.74 mm (80-258 mm ± 22.71 mm) and mean weight was 70.90 g (10- 160 g ± 23.99 g). There were significant differences in length for the periods of the year. The increase of the species was negative allometric (b = 2.34). The sex ratio was 2:1 favoring females. The relative abundance and biomass were higher in the reservoir and lake area. Spawning occurred between the months of November 2009 and January 2010, individuals preferentially spawn in the reservoir and the lake. The total spawning type and size at first maturity is from 157.5 mm. The species has iliófaga-detritivorous feeding habit with a tendency to omnivory. The feeding strategy is general, but dominant for items phytoplankton and detritus. The species H. unimaculatus, has adapted successfully to the dams and their diet may have been altered before the changes caused by the environment.Item Acesso aberto (Open Access) Ecologia e etnoecologia de Hypancistrus zebra (Siluriformes: Loricariidae) no rio Xingu, Amazônia brasileira(Universidade Federal do Pará, 2011-08-05) GONÇALVES, Alany Pedrosa; NAHUM, Victoria Judith Isaac; http://lattes.cnpq.br/3696530797888724H. Zebra is a fish species of the Loricariidae family, Ancistrinae subfamily, endemic of the Xingu River, with distribution from Belo Monte to the confluence of the Xingu and Iriri rivers. Being a species with great market value aquarist ornamental his capture became rampant, making it an endangered species. Despite strong pressure on H. zebra, there are still few studies on the species. Thus, given the scarcity of basic information and the constant threats, knowing the biology and ecology of H. zebra, aggregating the results of scientific research, also the local ecological knowledge of fishermen ornamental trade about this species becomes an essential tool for the conservation of the species. The distribution of H. zebra is restricted to a small stretch of the Xingu River, between Gorgulho da Rita and Itaubinha, and does not occur evenly, it depends on the presence of boulders. A total of 283 individuals of H. zebra were visualized in the rocky outcrops of the study area, of which 232 were captured. The lowest average abundance was Gorgulho da Rita, as opposed to the site Jericoá with the greatest abundance. Between periods, there was a greater abundance in dry river and lowest value for the period of filling. Environmental factors had no significant influence on the abundance of H. zebra. H. zebra is a generalist species, feeding mainly of periphytic algae, debris, plant debris and sponges, while nematodes and millipedes were considered occasional items. Diet composition and abundance of H. zebra showed no significant differences for collection sites, periods of the year and ontogeny. Considering the composition and abundance of the diet, H. zebra can be considered an iliophagousomnivorous, and ability to adapt changes in food availability in the construction of the Hidroeletric Belo Monte. Ornamental trade fishermen demonstrate expert knowledge concerning the distribution and abundance, habitat, feeding, predation and reproduction of the H. zebra, which can be used to optimize work and to facilitate future management measures. The construction of the Hydroeltric Belo Monte Hydroelectric is a threat to the survival of H. zebra and future studies and monitoring of the species are needed, either as mitigation of impacts, either as to captive breeding as an alternative income coastal communities who depend on fishing on the Xingu river ornamental.