Ecologia Trófica de Pimelodella lateristriga (Osteichthyes, Siluriformes) do rio Mato Grosso, Saquarema - RJ

Abstract

This work aims to describe various aspects of the feeding ecology of Pimelodella lateristriga (Lichtenstein 1823) related to the spatial and temporal variations and ontogenetic on Mato Grosso stream, Saquarema - RJ. The collecting sites were according to their different degrees of conservation of riparian vegetation. Samples were collected bimonthly from March/2006 to January 2007, using electricfishing and sieves.The dissertation was divided into two chapters, where each one deals with one aspect of the diet of the species. The first chapter deals with spatial and temporal variations of the diet, where we found differences in the number and size of items consumed by the species in two separate locations, but the feeding habits of the species omnivorous with a tendency to insectivory) was maintained regardless of location. The second chapter deals with ontogenetic shifts in the diet of the species. Differences in intestine length were observed, also in the use of allochthonous and autochthonous resources by young and adults individuals, with predomination of autochthonus items for young. The size of ingested items, was also different, with the young consuming smaller items than adults. We conclude that P. lateristriga of Mato Grosso stream has an omnivorous diet, with a tendency to insectivory, has spatial variation in diet in relation to the number and size of items consumed, has no seasonal variation in diet, since we found no pattern of use of items of different nature in relation to months of study and that the species has ontogenetic diet shifts.