Revista Chilena de Historia Natural 83 (2): , 2010
RESEARCH ARTICLE
Endemism analysis of Chilean freshwater mollusks
The Chilean geological and climatic diversity allows the differentiation of a great variety of
terrestrial and aquatic ecosystems. Evidence provided by distributional patterns of freshwater species suggests a correspondence
with Pleistocene glaciations, and some post-glacial tectonic events that affected the hydrography of the country. The species of
freshwater 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 freshwater mollusk species, suggests the existence of three main
biogeographic areas: Northern (between latitudes 17°-33° S), Central Southern (33°-44° S) and Southern (44°-56° S). Hydrographic
zone V (44°-56° S), included in the Southern area, has the highest endemism percentage (75 %), contrasting with hydrographic zone I
(17°-26° S), included in the Central-Northern area, which registered the lowest value (42 %).
Key words:
biodiversity,
biogeography, freshwater molluscs, hydrographic zones, PAE
