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Title: Variação diária e caracterização morfológica das larvas de peixes do complexo estuarino do Rio Amazonas - PA
metadata.dc.creator: ZACARDI, Diego Maia
metadata.dc.contributor.advisor1: NAKAYAMA, Luiza
Keywords: Peixe
Recursos pesqueiros
Estágios do ciclo de vida
Rio Amazonas
Pará - Estado
Amazônia brasileira
Issue Date: 2009
Publisher: Universidade Federal do Pará
Empresa Brasileira de Pesquisa Agropecuária
Universidade Federal Rural da Amazônia
Citation: ZACARDI, Diego Maia. Variação diária e caracterização morfológica das larvas de peixes do complexo estuarino do Rio Amazonas - PA. 2009. 106 f. Dissertação (Mestrado) - Universidade Federal do Pará, Núcleo de Ciências Agrárias e Desenvolvimento Rural, Empresa Brasileira de Pesquisa Agropecuária, Universidade Federal Rural da Amazônia, Belém, 2009. Programa de Pós-Graduação em Ciência Animal.
Abstract: The great importance of fishery resource for Amazonia, together with the necessity of more detailed basic information on identification of fish larvae (captured in their natural environment) justify the development of this study, which has the aim of expanding the knowledge about ichthyoplankton, relating it to diel variation tendency and tides from the estuarine complex of Amazonas river, PA. The material was collected during diurnal and nocturnal periods, in the second semester of 2007, by the PIATAM mar II project, under the subarea 1 (estuary of Paracauari river) and subarea 2 (Guajara Bay) in the tide sizigia and quadrature, in horizontal trawls the water column surface cylindrical-conical plankton 300μm mesh. The samples were maintained in recipients containing 4% formalin. Hydrologic factors were obtained in situ by the Chemical Oceanography Group of the Museum of Paraense Emilio Goeld, and were sorted and identified through on morphological, morphometric and meristic characteristics based on the development regressive sequence technique and specialized bibliography. The main structures and characteristics of the initial phases of fishes were described and illustrated, facilitating future studies focusing ichthyoplankton of the region. Superficial temperature of the water, hydrogenionic potential and dissolved oxygen did not show significant differences in the areas studied. The values of salinity did not show significant differences in relation to seasons of sampling and tides, registering only horizontal variation with the gradual increase in direction of the mouth river with high (12) and minimum (0) values to subareas 1 and 2, respectively. The highest densities of eggs were registered in subarea 1 in comparison with subarea 2. Moreover, highest densities of eggs were observed during diurnal period (163, 29 eggs/100m³), while in subarea 2 they were observed during nocturnal period (19,70 eggs/100m³). Larvae were distributed in 22 taxa representing 13 families and 21 species. The predominant taxa were: P. flavipinnis (46,29%), R. amazonica (19,75%), Engraulidae (10,70%), P. squamosissimus (7,55%), A. lineatus (5,19%), O. saurus (3,30%) and Gobiosoma sp. (2,15%), with a relative high participation of Clupeiformes (76,75%). When considering the development stage, it was observed a higher abundance of pre-flexion larvae in both subareas, while the stages yolk-sac and pos-flexion were less observed. Nocturnal period showed the highest density of larvae and number of taxa, evidencing a possible nictemeral migration of the plankton. Only M. furnieri showed significantly higher abundances in diurnal samples. The great majority of taxa did not present significant differences between diurnal and nocturnal samples. Hence, the density of larvae and number of taxa differ between diurnal and nocturnal periods and between tides. As a consequence, the morphologic characteristic described in this study allow an adequate identification of larvae, amplifying the biologic knowledge of the estuarine species from Para coast, considering that this information is still scarce and there is a necessity of intensification in this kind of research. Moreover, the comprehension of the ecology of the organisms, especially the ones which have life cycles associated to estuaries and the variations in the transport of larvae between diurnal and nocturnal periods, as well as between tides. These are fundamental topics to improve the management and conservation of these renewable resources.
Appears in Collections:Dissertações em Ciência Animal (Mestrado) - PPGCAN/Castanhal

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