Effects of physical and chemical factors on Ephemeroptera (Insecta) assemblages in an urban river of the eastern Colombian Llanos

Abstract

The mayflies are insects widely known as indicators of aquatic quality in freshwater systems, they are abundant and diverse in tropical streams. In this study, it was determined the influence of physical, chemical and bacteriological characteristics on the Ephemeroptera assembly in a period of low precipitation in the Ocoa river of Meta department. There were 5,332 nymphs belonging to 4 families, 10 genera and 3 species. Three new genera records and one species are presented for Meta: Cloeodes, Zelusia, Lumahyphes and Americabaetis alphus. The genera Camelobaetidius and Varipes were found associated with conditions of contamination by organic matter and water mineralization. Likewise, Americabaetis, Thraulodes, Lumahyphes and Tricorythodes were associated with contamination conditions, especially with nitrites and nitrates. Nanomis, Cloeodes and Zelusia showed greater sensitivity to the contamination condition and were related to high percentages of dissolved oxygen in the water and they were in the sampling stations of the upper part in the river. It is important to mention that there were not Ephemeroptera in most of the stations associated with the urban area. That reflects their high sensitivity to polluting conditions at low precipitation period.

Diversidad Funcional Y Taxonómica De Insectos Acuáticos (Ept) en Un Río Urbano Del Piedemonte Llanero Colombiano

“…También se registraron los valores más altos en tensoactivos aniónicos, fuente importante de deterioro de calidad de agua, que junto a los ortofosfatos (>2,22 mg/LPO4 3-) asociados a contaminación por descargas domésticas y agrícolas señalan alta contaminación y eutrofización del sistema (Gómez-Anaya et al, 2017;Solari et al, 2013). Smicridea disminuyó drásticamente su abundancia a pesar de que ha registrado tolerancia a la contaminación (Vásquez-Ramos et al, 2014) y su preferencia alimentaria por materia orgánica particulada gruesa y fina (Álvarez-Soraca et al, 2017) ofertada ampliamente en el tramo medio del río; contrariamente, Americabaetis aumentó en estas condiciones de alta turbidez y DQO en el agua, género que ya ha sido asociado a condiciones de contaminación por materia orgánica (Rojas-Peña et al, 2021).…”

Influencia de las prácticas agrícolas en los ensambles de macroinvertebrados en la Patagonia (Argentina)

“…As expected, in the present study macroinvertebrate assemblages at UNR showed a higher abundance and richness of taxa sensitive to organic contamination such as Trichoptera (Glossosomatidae and Hydropsychidae) and Ephemeroptera (Leptophlebiidae, Baetidae and Caenidae) than at DNR. These groups are widely accepted as bioindicators of good water quality (Brasil et al 2014;Kubendran et al 2017;Thamsenanupap et al 2021) and are highly sensitive to agricultural pollution, including nutrients and pesticides (Schulz et al 2002;Beketov 2004;Thiere and Schulz 2004;Beuter et al 2019;Vilenica et al 2020;Rojas-Peña et al 2021).…”

Ictiofauna de la subcuenca urbana del río Ocoa, drenaje superior del río Meta, cuenca del Orinoco, Colombia

“…obs.). However, the Ocoa River is the main recipient of more than 100 discharges from the urban center, serving as a sink for 80% of urban wastewater (Osorio-Ramírez et al, 2015), promoting degradation and ecological loss of the riverbed (Aguilera-Giraldo et al, 2019;Rojas-Peña et al, 2021).…”