Crustacean (Copepoda and Cladocera) zooplankton richness in Chilean Patagonian lakes

The Chilean Patagonian lakes are characterized by their oligotrophy, high endemism, significant predominance of calanoid copepods in comparison to daphnid cladocerans, and low species richness. These characteristics are in marked contrast to the situation in North American lakes. In the present study, published information of chlorophyll concentrations and species richness for Chilean Patagonian lakes was considered. The results denoted direct correlations between chlorophyll concentration and species richness, as well as an inverse correlation between latitude and species richness, whereas a relationship between lake surface and species richness was not observed. The results obtained would indicate that the oligotrophic status of the sites studied is the main cause of low species richness. Our conclusions most probably reveal the existence of different regulator mechanisms in comparison to North American lakes. Ecological and biogeographical topics are discussed