Ecology of freshwater ostracods from Northern Patagonia and their potential application in paleo-environmental reconstructions

Abstract

In order to generate a database of the auto-ecology and distribution of Argentinian North Patagonian ostracods (Argentina), a survey in 40 aquatic systems has been carried out. For this purpose, we report the ostracod diversity and assess the relationships between ostracod occurrence and abundance considering abiotic environmental variables. Twenty-two ostracod species have been found, three of which first record for Neotropical region and one for Argentina. Conductivity, temperature, and energy level have significantly explained ostracod distribution and abundance. Based on host waters features, three ostracod assemblages have been recognized: (1) temperate waters with moderate to high conductivity have presented in Sarscypridopsis aculeata, Potamocypris unicaudata, Heterocypris hyalinus, and Cypridopsis vidua as typical fauna; (2) environments with flowing waters were dominated by Ilyocypris ramirezi and Heterocypris incongruens, whereas (3) in cold and low conductivity environments, Tonnacypris lutaria, Eucypris virens, and Bradleystrandesia fuscata were the characteristic taxa. Our data indicate that Patagonian ostracods are largely influenced by host waters features, mainly conductivity and temperature. Likewise, due to the fact that eight of the twenty-two identified taxa in this survey were recovered in Holocene sequences from Patagonia, this study provides valuable information for future paleo-environmental reconstructions in North Patagonia.