Abstract

MOTTA DIAZ, Ángela; ORTEGA CORREDOR, Laura; NINO FERNANDEZ, Yeina  and  ARANGUREN RIANO, Nelson. FUNCTIONAL FEEDING GROUPS OF AQUATIC MACROINVERTEBRATES IN A TROPICAL STREAM (COLOMBIA). rev.udcaactual.divulg.cient. [online]. 2016, vol.19, n.2, pp.425-433. ISSN 0123-4226.

Aquatic macroinvertebrates are an important biological component of rivers because they contribute to the flow of matter and energy. The goal of this study was to determine the structure and functional feeding groups of macroinvertebrates in the stream La Chapa (Dpto. Boyacá). In three sections of the stream, during the rainy and dry seasons, we measured physical and chemical characteristics of the water and used a surber net to obtain macroinvertebrate samples. Next, all species were identified, abundance and biomass calculated, then assigned each taxon to a functional feeding group based on dietary preferences. In the principal component analysis the physical and chemical variables were organized according to seasonality, electric conductivity, hardness and alkalinity. Thirtyfive macroinvertebrate taxa were found, with a high abundance of mayflies and diptera, with 8 and 7 taxa respectively. During the rainy season the stream was dominated by collector-gatherer and collector- filter organisms including Thraulodes sp. and Simulium sp., while in the dry season scrapers such as Helycopsyche sp. were more common. In terms of biomass, the rainy season was composed primarily of the driller-carnivore Limnocoris sp., while in the dry season the biomass of the scrapers such as Hydrobiidae increased. The temporal variation in the functional feeding groups that we observed is likely a consequence of changes in habitat conditions over time. In conclusion, our work supports the role for seasonal changes in structuring the phenology of macroinvertebrate communities in Andean lotic ecosystems.

Keywords : Macroinvertebrates; trophic structure; headstreams; Andes.

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