Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

Autor(es)

Vidotto-Magnoni, Ana Paula ^[1] ; Carvalho, Edmir Daniel ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Biociencias Botucatu, Dept Morfol, Lab Biol Ecol Peixes, BR-18600000 Botucatu, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Neotropical Ichthyology; v. 7, n. 4, p. 701-708, DEC 18 2009.
• Citações Web of Science: 19

Resumo

We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes. (AU)

• Processo FAPESP: 02/11113-6 - Estudo da comunidade de peixes do reservatorio de nova avanhandava, bacia do rio tiete - sp, com enfase na dinamica alimentar das especies introduzidas e suas interacoes troficas com a ictiofauna nativa.
• Beneficiário: Ana Paula Vidotto Magnoni
• Modalidade de apoio: Bolsas no Brasil - Mestrado