Feeding ecology and habitat preferences of the catfish genus Trichomycterus in low‐order streams of the Colombian Andes

Abstract

Six lower order streams in the south-west of Colombia were sampled on a monthly basis in order to determine the status of Trichomycterus species in relation to their food supply (macroinvertebrates), and physico-chemical habitat. Fishes were sampled by electrofishing and samples taken for dietary analysis. Macroinvertebrates were collected using a Surber sampler. Trichomycterus spp. populations were present in all streams in habitats ranging from soft to hard substrata and from relatively stagnant waters to fast flowing streams. The average density of the fishes ranged from 0Á06 to 1Á14 individuals m À2 with peaks in population corresponding to recruitment of individuals of <1 g. Trichomycterus spp. were found to be benthic carnivores with a diet mostly of aquatic insects. The index of relative importance for the dietary items was 35Á0, 10Á5, 1Á9 and 7Á8% for Chironomidae, Trichoptera, Ephemeroptera and Oligochaeta respectively. Combined with physical habitat data, ordinations of fishes and macroinvertebrate data suggested that differences in abundance among sites were driven by stream size and flow regime, indicating dominance of the physical habitat, although a high correlation between Trichomycterus spp. and Chironomidae abundances (r ¼ 0Á81, P ¼ 0Á049) was also recorded.

Population biology of Trichomycterus sp. (Siluriformes, Trichomycteridae) in Passa Cinco stream, Corumbataí River sub-basin, São Paulo State, southeastern Brazil

“…was composed mainly of aquatic insects, and immature Diptera was the most important item. Other previous studies confirm the information regarding the diet of Trichomycterus (Casatti, 2003;Habit et al, 2005;Chará et al, 2006 andScott et al, 2007). Therefore, we can include Trichomycterus sp.…”

“…Some aspects of diet and/or reproduction are known for T. aerolatus (Manriquez et al, 1988;Huaquín et al, 2002;Habit et al, 2005 andScott et al, 2007), T. caliensi (Román-Valencia, 2001), T. chaberti (Pouilly and Miranda, 2003), T. chiltoni (Scott et al, 2007), T. corduvense (Marraro et al, 2005), T. itacarambiensis (Trajano, 1997) and two other species are still not resolved taxonomically (Casatti, 2003 andChará et al, 2006).…”

A Comparative Study of Leaf Breakdown of Three Native Tree Species in a Slowly‐Flowing Headwater Stream in the Colombian Andes

“…Densities of macroinvertebrates in the Surber samples of the present study averaged 122.7 individuals per m 2 which is low as compared to tropical streams in other regions (FLECKER and FEIFARECK, 1994;PAABY et al, 1998). However, other studies carried out in 1 st and 2 nd order streams in Colombia have produced macroinvertebrate densities ranging from 98 to 325 individuals per m 2 (CHARÁ et al, 2006) showing that low densities of macroinvertebrates could be a common feature of headwater streams in the Andes.…”

Compartilhamento de recursos por duas espécies de peixes nectobentônicas de riachos na bacia do rio Cachoeira (BA)

“…A preferência por larvas de Diptera foi verificada para Trichomycterus spp. no rio Passa Cinco (Rondineli et al 2009), em um riacho no Parque Estadual do Morro do Diabo (Casatti 2002(Casatti , 2003, em riachos no Chile (Habit et al 2005) e na Colômbia (Chará et al 2006). Espécies dos gêneros Characidium e Trichomycterus amostrados em riachos de Mata Atlântica foram classificadas como insetívoras, com preferência por insetos aquáticos, em diversos estudos (Sabino & Castro 1990, Castro & Casatti 1997, Aranha et al 1998, Esteves & Lobón-Cerviá 2001, Motta & Uieda 2004, Castro et al 2004, Barreto & Aranha 2006, Esteves et al 2008, Rondineli et al 2009).…”