Abstract

GONZALEZ-TUTA, Ángela Liceth  and  GIL-PADILLA, Luz Nidia. Composition of macroinvertebrates in the provinces of Márquez and Lengupá and the possible effect of orogenesis on their distribution. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2020, vol.44, n.171, pp.572-580.  Epub June 12, 2021. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.1037.

The orogenesis of the Andes in Colombia modified the landscape and the climate causing their elevation thus interrupting the atmospheric circulation, which led to increased rainfall on their eastern flank. This transformed the continental hydrographic network and increased the availability of nutrients originating, consequently, a great variety of habitats for flora and fauna in the country. The elevation of the mountain ranges promoted the appearance of vicariant speciation and genetic isolation, which partially explains the patterns of accumulation of biodiversity as an important part of the trophic processes of the systems. In this context, we made point collections during 2011 and 2012 in 10 streams located in the provinces of Márquez and Lengupá in the center-south of Boyacá to establish the composition of macroinvertebrates on the eastern flank of the Eastern Cordillera and the differences in the groups present compared to the other two Colombian mountain ranges. We collected semi-quantitative samples with a 500 um screen network; the specimens were fixed in the field in 96% ethyl alcohol and later preserved in the laboratory in 70% ethyl alcohol; the taxonomic identification was established in the lowest possible taxonomic level. The results showed that the Orthocladiinae and Tanypodinae subfamilies and the Hyalella genus were the most abundant. Grumichella and Polycentropus genera had not been registered for the central and western mountain ranges and they show differentiation, but it was not possible to conclude that they are endemisms as in most of the previous studies, the taxonomic level does not allow to establish if they are the same species or not. Thus, the works must be completed at a more specific level.

Keywords : Andes Mountains; Dispersion; Divergence; Ecosystems aquatic; Orogeny.

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