Zooplankton in Lake Zempoala, Lagunas de Zempoala National Park, Morelos, Mexico.

The zooplankton of Lake Zempoala play a key role in aquatic ecosystems, as they feed on microalgae and serve as a source and transfer of energy for juvenile fish.For this reason, the present study aims to provide recent information on the zooplankton richness of Lake Zempoala and its relationship with some physicochemical parameters of the water.Sampling was carried out in three months during the cold rainy and dry seasons.Three monitoring stations were located in the aquatic system and water samples were taken to determine the water quality and its relationship with the organisms.Twenty species of zooplankton were identified, distributed in two phyla: Rotifera and Arthropoda.Rotifers represented 65% of the species richness, with the Brachionidae family being the most diverse, cladocerans made up 25% and copepods 10%.The sampling stations (E1, E2 and E3) showed differences in richness, with September being the month with the highest number of species ( 18).Asplanchna sieboldi and Brachionus havanaensis were the common species in all stations.The physicochemical characteristics of the water revealed that the lake has alkaline conditions and moderate levels of conductivity and dissolved oxygen, with seasonal variations.The highest oxygen levels were recorded in February, while September showed the highest species richness.In general, these relatively stable environmental conditions favored zooplankton biodiversity during the study period.Lake Zempoala, with moderate zooplankton diversity and environmental stability, offers a suitable environment for the persistence of this community, despite seasonal fluctuations.