title: Feeding and reproductive patterns of Astyanax intermedius in a headwater stream of Atlantic Rainforest.
abstract: In this paper, we determined diet composition, reproductive periodicity and fecundity of Astyanax intermedius in a headwater stream of a State Park of an Atlantic rainforest. We also evaluated the influence of rainfall, water temperature and fish size on niche width and niche overlap. Sampling was conducted monthly throughout one year in the Ribeirão Grande stream, southeastern Brazil. Diet consisted of 31 food items with equal contribution of allochthonous and autochthonous items. Females were larger than males, and the mean sizes at first maturation were 4.44 cm and 3.92 cm, respectively. Based on 212 pairs of mature ovaries, the number of oocytes per female ranged from 538 to 6,727 (mean = 2,688.7). Niche width and niche overlap were not related to rainfall nor water temperature and only niche width increased with fish size, suggesting that as fish grow, more items are included in diet. Our results suggested that A. intermedius fit as a typical opportunistic strategist which may explain the prevalence of this species in several isolated headwater basins of vegetated Atlantic forested streams where food resources are abundant and distributed throughout the year.
authors.affiliation: Programa de Pós-Graduação em Sustentabilidade de Ecossistemas Costeiros e Marinhos, Universidade Santa Cecília, Santos, SP, Brasil.
authors.forename: Ursulla P
authors.initials: UP
authors.lastname: Souza
authors.affiliation: Departamento de Ciências do Mar, Universidade Federal de São Paulo, Santos, SP, Brazil.
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Ferreira
authors.affiliation: Programa de Pós-Graduação em Sustentabilidade de Ecossistemas Costeiros e Marinhos, Laboratório de Pesquisa em Recursos Pesqueiros, Universidade Santa Cecília, Santos, SP, Brasil.
authors.forename: Michele A F
authors.initials: MA
authors.lastname: Carmo
authors.affiliation: Departamento de Zoologia, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", Rio Claro, SP, Brazil.
authors.forename: Francisco M S
authors.initials: FM
authors.lastname: Braga
mesh_terms: D000818:Animals; D001938:Brazil; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005399:Fishes / Q000145:classification / Q000502:physiology*; D005766:Gastrointestinal Contents; D008297:Male; D065947:Rainforest; D012098:Reproduction / Q000502:physiology*; D012621:Seasons