Abstract

AGUILERA-GIRALDO, Ivonne Alexandra  and  VASQUEZ-RAMOS, Jesús Manuel. Spatial and temporal distribution of Elmidae (Insecta: Coleoptera) and its relationship with physicochemical parameters in the Ocoa river, Meta, Colombia. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2019, vol.43, n.166, pp.108-119. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.833.

The riffle beetle (Coleoptera) are aquatic organisms of worldwide distribution. Their immature and adult forms occupy a wide range of substrates and habitats and they are a diverse group. Our study aimed to determine the spatial and temporal distribution of the family Elmidae and its relationship with physicochemical parameters in the Ocoa River. We established 15 sampling stations and reviewed a total of 210 samples of macroinvertebrates collected in the rock-pebble substrate using Surber nets (250 μιη) in two contrasting hydrological periods (low and high rainfall): October 2014 and February 2015. We obtained 37 organisms (larvae and adults) from nine genera of Elmidae: Heterelmis, Huleechius, Macrelmis, Astrolimnius, Microcylloepus, Neoelmis, Hexacylloepus, Cylloepus, Notelmis and Phanocerus, of which seven corresponded to new records for the Colombian Orinoquia region. During the low rainfall period, the representation was higher, with 35 records of nine genera, while during the high rainfall period, there was a marked decrease in richness, with only two records corresponding to two genera. In general, the abundance of Elmidae was low along the river; the stations located in the sector crossing the city of Villavicencio, with a more deteriorated habitat, harbored the lowest abundance and in some, no riffle beetles were registered. The environmental effects of urbanization, such as contamination by organic matter and the growth of coliform bacteria due to wastewater discharges, were the main determinants of the decrease in the richness and abundance of these organisms. The present study is the first exploration of Elmidae in the zone and contributes to the ecological knowledge of Coleoptera fauna in urban basins of the Colombian Orinoquia. © 2019. Acad. Colomb. Cienc. Ex. Fis. Nat.

Keywords : Bioindicator; Coleoptera; Elmidae; Urban basin; Orinoco.

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