Endemic species: Contribution to community uniqueness, effect of habitat alteration, and conservation priorities

摘要: The biodiversity crisis, particularly dramatic in freshwaters, has prompted further setting of global and regional conservation priorities. Species rarity endemism are among the most fundamental criteria for establishing these We studied patterns role rare species community uniqueness using data on freshwater bivalve molluscs (family Unionidae) Texas. Due to large size gradients landscape climate, Texas diverse distinct unionid communities, including numerous state endemic species. Analysis state-wide distribution abundance Unionidae allowed us develop a non-arbitrary method classify based their range relative density. Of 46 currently present Texas, 65% were classified as very rare, all endemics. found that critical component defining communities. Almost endemics exclusively streams rivers, where diversity was almost double lentic waters. Man’s ongoing alteration lotic with waterbodies favors common species, dramatically reduces habitat endemics, contributing homogenization fauna. identified hotspots endemism, prioritized need protection, estimated population size, recommended changes current status.