Larvas de peixes do reservatório da usina hidrelétrica de Tucuruí - Pará

Abstract

The alternations in Brazilian watersheds, caused by the anthropic action of construction of reservoirs by hydroelectric plants cause changes in biological communities, leading to a new configuration in the environment, with introduction or extinction of fauna and flora species. Due to the importance of fishery resources to amazon region and in order to generate data about the study of fish larvae in a reservoir environment, this recent study tried to determine the diversity of planktonic Ichthyofauna of Tucurui's Hydroelectric Plant and verify their abundance and distribution. Samples were made in sep/2009, jul/2010, feb/2011 and may/2011, in 10 sampling stations distributed over the studied area, by sub superficial trawls in the water column, using a conical-cylindrical plankton net with mesh of 300 um, after captured, larvae were screened, counted and identified at the lowest possible taxonomic level. In data analysis, In the data analysis was used the Kruskal-Wallis test to identify the possible differences in spatial distribution and relation with abiotical factors. Were captured 429 larvae distributed in 5 orders: Characiformes, Clupeiformes, Perciformes, Pleuronectiformes, Tetradontiformes and 5 families: Hemiodontidae, Engraulidae, Sciaenidae, Tetradontidae e Achiridac, being the Scianidae the most abundant, with 72,96% of total identified larvae, represented by the species: Plagioscion squamosissimus and Plagioscion sp., total density of 2,63 larvae/100m" being considered constant through Tucurui's Hydroelectric Plant reservatory. The other identified families: Engraulidae, Achiridae, Hemiodontidae, Tetraodontidae totaled together O, 73 larvae/ 100m'. Were not observed any significant differences in the Environmental and hydrological Parameters in relation to the expeditions and collecting stations over Tucurui's Hydroelectric Plant reservatory. The comprehension of the ecology of organisms about everything, in addition to those who present have their life cycle associated with the influence of rivers and dams of reservoirs, are fundamental questions to increase management and the conservation of these renewable resources.