%0 Journal Article
%T Longitudinal use of feeding resources and distribution of fish trophic guilds in a coastal Atlantic stream, southern Brazil
%A Luciano Lazzarini Wolff
%A Nat¨¢lia Carniatto
%A Norma Segatti Hahn
%J Neotropical Ichthyology
%D 2013
%I Sociedade Brasileira de Ictiologia
%X This study described the use of food resources and the distribution of fish trophic guilds along the longitudinal gradient of a coastal Atlantic stream, southern Brazil. Allochthonous resources (terrestrial insects) predominated in the headwaters, whereas autochthonous food items (algae, fish) and detritus predominated in the mouth section. Detritivorous, aquaticinvertivorous, and terrestrial- and aquatic-insectivorous species occurred throughout the gradient, while omnivorous and piscivorous in the headwaters and middle stretches, respectively, and herbivorous in the middle and mouth. Detritivores and aquatic-insectivores were significantly more specialized than the other guilds, however, there was no evidence of a longitudinal increase in trophic specialization. Density and biomass of aquatic-invertivores and aquatic-insectivores decreased, whereas that of detritivores increased longitudinally. The distribution of trophic guilds was significantly associated with the stream section, where aquatic and terrestrial insectivorous were more frequent in rocky and flowed stretches from the headwater and detritivores in deeper environments with finer particles of substrate from the mouth. This suggests that fish assemblages in coastal streams with a steep longitudinal gradient may follow patterns in the use of food resources according with the food availability along the river, as predicted by the River Continuum Concept. Este estudo descreve o uso dos recursos alimentares e a distribui  o das guildas tr¨®ficas de peixes ao longo do gradiente longitudinal de um riacho da encosta Atlantica, Sul do Brasil. Recursos al¨®ctones (insetos terrestres) foram consumidos com maior frequ¨ºncia na cabeceira, entretanto, recursos de origem aut¨®ctone (algas, peixes) e detritos foram mais frequentemente registrados na foz. Esp¨¦cies detrit¨ªvoras, invert¨ªvoras aqu¨¢ticas, inset¨ªvoras terrestres e aqu¨¢ticas ocorreram ao longo de todo gradiente, enquanto que as on¨ªvoras e pisc¨ªvoras na cabeceira e meio, respectivamente, e herb¨ªvoras no meio e foz. Detrit¨ªvoras e inset¨ªvoras aqu¨¢ticas foram significativamente mais especializadas em rela  o ¨¤s demais guildas; entretanto, n o houve nenhuma evid¨ºncia de aumento longitudinal da especializa  o tr¨®fica. A densidade e a biomassa de invert¨ªvoras e inset¨ªvoras aqu¨¢ticas diminu¨ªram, enquanto que das detrit¨ªvoras aumentaram no sentido cabeceira-foz. A distribui  o das guildas tr¨®ficas foi significativamente associada com a sec  o do riacho, onde inset¨ªvoras aqu¨¢ticas e terrestres foram mais frequentes em trechos rochosos e de elevado fluxo da c
%K Atlantic Rainforest
%K Food availability
%K Freshwater fish
%K River Continuum Concept
%K Trophic structure
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013005000513