Zooplankton composition, abundance and water quality in a microreservoir at Morelos State

Abstract

The aim of the present work was to analyze the zooplankton composition, abundance and species richness at Huitchila microreservoir (called bordo in Spanish), Morelos, Mexico and their relationship with environmental conditions between September 2010 and September 2011. Sixteen zooplankton species belonging to three main groups were identified at the bordo: 11 rotifers, 3 cladocerans, and 2 copepods. The most frequent species was the copepod Arctodiaptomus dorsalis, occurring in 100% of the samples, with a density of 1 182 org/L. Among the cladocerans, Diaphanosoma birgei was the most frequent and abundant (100% and 85 org/L, respectively). The most abundant rotifer species was Brachionus falcatus (1 511 org/L) and the most frequent was B. caudatus (92%). The family Brachionidae had the highest species richness in the surveyed system. The highest zooplankton abundances and species richness were recorded during the dry season. Huitchila microreservoir is a eutrophic system, with warm water (20.3-28 °C), high availability of dissolved oxygen (4.1-16.2 mg/L), slightly alkaline, hard waters, with low conductivity (693-1258 µS/cm). This aquatic system is productive and has high food availability for the tilapia Oreochromis niloticus, a local fisheries resource.