Habitat use and food partitioning of the fishes in a coastal stream of Atlantic Forest, Brazil

Abstract

We analysed the fish assemblage in the "Mergulhiio" stream (soulhem Brazil) with underwater observations for habitat use, considering water depth, current velocity, bottom type, shadow froID vegetation cover, distance of stream-edge, and vertical position. Stomach contents or foregut content samples of the most abundant species were collected from 26 species (lO families). The fish assemblage occupied the bottom stream. The similarity analysis of spalía! occupation of species grouped four habitat use guilds: A) "Iambaris" (Aslyanax sp. and Deutetodon langei), Characidium spp. (C. lane; and C. plerosliclum) and Rineloricaria kronei used the bottom in deep sites and waters with middle current; B) Pimelodella pappenheimi and Corydoras barbalus used the bottom in siles with JOwer cUI'l"ént; C) Mimagoniates microlepis used the surface of the water column; and D) Phalloceros caudimacullUus used shallow sítes and waters without current. Species with few records were analysed descriptively. Diet similarity suggested seven trophic guilds: Microglanis sp. and PiTMIodella pappenheimi: omnivorouslca:mivorous gui14; Corydoras barbatus: omnivorous/insectivorous guild; Characidium [ane;: aquatic insectivorous guild, Ilillinly aquatic insects; Mimagoniates microlepis: terrestriál insectivorous guild, mainly te.rrestrial insects; Deuterodon [angei and ASlyanax sp.: omnivorous/herbivorous guild; Rineloricaria kronei, Kronichth.yssubteres, Schizolecis guntheri. Hisonotus leucofrenatus and Pseudotothyris obtusa: herbivÓfous guild; and PhaUoceros caudimaculatus: a!givorous guild. When the guilds were similar, the species were geÍletalists in diet and in habitat use.