Endemism analysis of Chilean freeshwater mollusks

Abstract

The Chilean geological and climatic diversity allows the differentiation of a great variety of terrestrial and aquatic ecosystems Evidence provided by distributional patterns of freeshwater species suggests a correspondence with Pleistocene glaciations, and some postglacial tectonic events that affected the hydrography of the country The species of freeshwater Chilean mollusks. unlike the marine species, have been undervalued Currently there are no biogeographic studies that would allow identifying distribution patterns and the possible processes that shaped them. A parsimony analysis of endemicity (PAE) and the richness of five hidrographic zones, based on 75 freeshwater mollusk species, suggests the existence of three main biogeographic areas Northern (between latitudes 17 degrees33 degrees S). CentralSouthern (33 degrees14 degrees S) and Southern (44 degrees56 degrees S) Hydrographic zone V (44 degrees56 degrees S), Included III the Southern area, has the highest endemism percentage (75 %), contrasting with hydrographic zone I (17 degrees26 degrees S), included in the CentralNorthern area, which registered the lowest value (42 %)