Composition and community structure of epilithic diatoms in the Vitor-Quilca-Chili river basin, Arequipa, Perú.

Coayla P.; Motta C.; Blanco S. · Darwiniana (2025) · DOI: 10.14522/darwiniana.2025.131.1224

Resumen

Diatoms have been studied as indicators of river water quality and their community structure can be influenced by different factors. We studied the epilithic diatom community and its relationship with environmental variables in the Vitor-Quilca-Chili basin of southern part of Peru in June and November of 2022. We identified 101 taxa where Nitzschia and Navicula presented the highest number of taxa. The Shannon index identified the most diverse diatom community in the Chili River (2.81) in June and in the Sumbay River (3.22) in November. The Simpson index identified communities with moderate dominance (0.47) in the Siguas River in November, but quite uniform according to the Pielou index. Variables such as electrical conductivity, flow, pH and organic matter probably determined the community structure. Furthermore, the taxon richness was higher in November (51) than in June. Our study also revealed higher values of deformities in the contour of the valves of the diatoms Cymbella excisa (12,11%) and Diatoma tenuis (20,89%) than those recorded in their natural environment.

Instituciones: Universidad Nacional de San Agustín de Arequipa