Diet composition of the mature larvae of four Anacroneuria species (Plecoptera: Perlidae) from the Venezuelan Andes

Abstract

The diet composition of the larvae of four Anacroneuria species from a Venezuelan river was studied (A. cacute, A. tachira, A. chorrera and A. paleta). Every four hours a D-net was used to obtain four samples in different sections of the channel. The gut content of the stonefly larvae was analysed, with Baetidae (Ephemeroptera) being the predominant prey for all four species. According to the electivity index, the four species have different prey choices, but they all preferred Simuliidae, and rejected Leptophlebiidae. Analysis of diet amplitude suggests that A. tachira is the most generalist and A. paleta the most specialist species, although high overlapping values indicate that all four species have very similar diets.

Keywords:

• stoneflies
• stream
• Anacroneuria
• diet
• Venezuela

Acknowledgements

The authors extend their thanks to Consejo de Desarrollo Científico Humanístico y Tecnológico (CDCHT) of the Universidad de Los Andes that supported this research (Proyect CDCHT-ULA C-960-99-01-C) and Dr Frances Osborn for revision of English.