CONICET | Buscador de Institutos y Recursos Humanos

Epibiosis is the association between two or more living organismsbelonging to the same or different species as a result of surface limitation. Besides the ecological significance, epibiosis is of interest in paleoecological studies of both recent and fossil organisms. Brachiopods provide an ideal biogenic substrate for studying paleoecological questions relating to encrusting biotas. The aim of this preliminary study is to describe brachiopods and their epibionts in living/recent/ Holocene shelled assemblages located along the Argentine coast between 40° and 55°S, at different depths. Representative brachiopod samples were collected.Living/recent samples were grouped into latitudinal areas to characterize organisms of high latitude (55°S approx.) and mid-latitude (40°S approx.), and benthic and coastal, depending on the bathymetric location where they were sampled. Six epibiont taxa were found on the living/recent valves of M. venosa and T. dorsata.The most frequent and abundant epibionts on both species were bryozoans andalgae. Additional organisms such as polychaetea, barnacles, brachiopods, andmolluscs were found. Benthic samples from high latitudes showed a higher overallrate of occurrence of epibionts. This difference is possibly determined by thebryozoans, which have the highest percentage of occurrence in this area and areusually predominant in these environments. The epibiont algae were found ingreater amounts in the mid-latitude coastal samples. The absence of encrustingbiotas on the Holocene shells of this study is attributed to the fact that many of these individuals are young and small. From this preliminary study, we intend to continue and deepen the analysis to assess potential ecological patterns and contribute to the knowledge of the epibionts and encrusting communities of Patagonian Quaternary brachiopods.