Abstract

HERNANDEZ, Ma. del Carmen; ESCOBAR, Elva  and  ALCOCER, Javier. Benthic crustaceans assemblage in a tropical, saline lake. Rev. Mex. Biodiv. [online]. 2010, vol.81, suppl., pp.133-140. ISSN 2007-8706.

This work acknowledges the composition, structure and spatial distribution of the benthic crustaceans assemblage of Alchichica, a tropical saline lake located in the easternmost portion of the Mexican highlands. The benthic crustaceans' assemblage was comprised by 1 amphipod (Hyalella azteca), 1 isopod (Caecidotea williamsi) and 2 ostracods (Limnocythere inopinata and Candona sp.). Compared to other tropical lakes the species richness is low. It is worth mentioning the high endemism found in the benthic crustaceans' assemblage of Lake Alchichica exemplified by C. williamsi, a new and recently described endemic species; additionally, it is to be expected that both, Candona as H. azteca are also new and endemic species of the lake. The benthic crustaceans were distributed from the coastal zone to the deepest part of the lake (62m) displaying variable abundances and taxonomic richness. The ostracodes were the most common crustaceans collected in the littoral zone, in the slope and in the deep zone where no other species were found. Amphipods were the second most abundant group in the coastal zone and in the slope being absent from the deep zone. Isopods are associated exclusively with the tufa deposits, a characteristic habitat of the lake that runs along the slope, so that traditional sampling techniques like those used in this study were unable to collect them. The crustacean assemblage is predominantly composed by species with direct development of diverse trophic positions including herbivores (H. azteca), omnivores (C. williamsi) and bacterivores (L. inopinata and Candona sp.).

Keywords : Alchichica; Mexico; ostracods; amphipods; distribution; abundance; biomass.