Unionida from Argentina: Distribution of the group and status of threat following the IUCN criteria

TORRES SANTIAGO; DARRIGRAN GUSTAVO

Cuiabá

Simposio; I Simpósio de conservacão de bivalves; 2018

Grupo de Ecologia e Conservação de Bivalves, Universidade Federal de Mato Grosso

In South America, the distributional range of the Unionida includes all countries in the region and extends as far south as the lakes and rivers of Argentinean-Chilean Patagonia. In Argentina, thirty-two species of naiads has been recorder since the first surveys in XIX century. The study of the group in the country reached its height between 1960 and 1980, producing valuable but now outdated information. With the aim of generating distribution range maps for the different genera of Unionida in Argentina and categorize the status of threat for the unionoidan species of Argentina, we analize: (1) bibliography available for the group; (2) databases of the nation?s main official malacological collections for the group; (3) status of threat for the species following IUCN criteria. The data were analyzed and georeferenced using the point-radius method. Spatial analyses were performed with the software Q-GIS 2.16.3 Nødebo using vector layers under the 2007 Argentinean Geodesic Positions reference system. A total 1,833 lots were analyzed, of which it was possible to georeference 1,503. The distribution of Unionida in Argentinean territory was analyzed according to political provinces, Surface Drainage Basins and the Argentinean Protected Areas. Species richness was analyzed using the surface drainage basins of Argentina. We generate distribution maps for each genus and discuss the species threat status and conservation degree in the region. Eighteen of the 23 Argentinean political provinces have at least one naiadspecies. Naiad distribution ranges from northern Argentina (23˚9'28''S,64˚19'47''W) (Jujuy Province) to the Patagonian lakes in the south (42˚58'35''S,71˚31'52''W) (Chubut Province). The Plata Basin was the hydrographic systemwith the highest richness, with species predominantly in the Parana´ and Uruguayrivers and their tributaries. Patagonia presented only two genera (Diplodon andAnodontites) with one species each, D. (D.) chilensis and A. (A.) puelchanus.More than 95% of the distributional range of the Unionida has no protected area.All the species evaluated were categorized as Data Deficient. This proves thatupdate data about naiad?s populations are neccesary for categorization of thestatus of threat of the group. The results of the present study will enable future research to enable the estimation of endangered status and degree ofconservation of unionidan species such as by detecting priority areas forconservation, selecting of areas for population studies, and species modellinglinking distributional ranges with environmental variables and climatic change.Conservation management is necessary for the preservation of Unionida diversityin southern South America. For more information see:https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0203616