Diets of leaf litter-associated invertebrates in three tropical streams

¹ Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria, CIPAV, Carrera 25 No. 6-62, Cali, Colombia
² Departamento de Biología, Grupo de Investigaciones Entomológicas, Universidad del Valle, Apartado Aéreo 25360, Cali, Colombia
³ Centro de Investigaciones y Estudios en Biodiversidad y Recursos Genéticos, CIEBREG, P.O.B. 97, Pereira, Colombia
⁴ School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia
⁵ Wetland Ecology Department, Doñana Biological Station-CSIC, Avda Americo Vespucio s/n, 41092 Sevilla, Spain

^* Corresponding author: ana@cipav.org.co

Received: 20 May 2011
Accepted: 27 October 2011

Abstract

Shredders play a major ecological role in temperate streams, but their numerical importance is highly variable within the tropics. Detailed studies on the diets of tropical stream invertebrates are advisable to be able to better describe and understand this variation. Here, we examined the diets of invertebrates collected from the leaf litter of three tropical streams in Colombia, using gut content analysis. Fine and coarse particulate organic matter were the main food resources for invertebrates, which could be divided into four main dietary groups: predators, shredders, specialist collectors and generalist collectors. While the specialist collectors were the most numerically abundant group (54%), shredder biomass accounted for 63% of total invertebrate biomass, suggesting that shredders play a significant ecological role in the study streams. We describe the diets of 12 out of 47 taxa that were previously unknown, which indicates that knowledge about the feeding ecology of tropical stream invertebrates is still incipient.