Shrimp-eating fishes and a case of prey-switching in Amazon Rivers

Abstract

There are two families of freshwater shrimp in the Amazon. Palaemonidae conta'ins four genera and 14 species (Kensley and Walker, 1982). Sergestidae is represented by only one genus, and it has two or three species. Over 50 species of Amazonian fishes have been reported to eat shrimp (Tab. 1). To date, however, no Amazon fish species has been identified as a shrimp-eating "specialist". ln this paper we report on one catfish and two croaker species which we believe eat shrimp as the main part of their diets, at least in some habitats.