Freshwater’s Fish Species Richness Patterns for Mexico

Fishes are the most diverse vertebrates, grouping about 28000 species. Mexico has 25% of this biodiversity and is recognized as the fourth place in the world with 500 species of continental fish, comprised of Nearctic and neotropical species. In this study, six fish collection databases were consulted, and by the use of metadata sites, we ordered and mapped all the continental metadata registers and by a manual search of water bodies, local names, and other site references were consulted for all registers and by the use of the latest taxonomical keys searching for synonyms to eliminate repeated records. We obtained a total of 23,113 registers ordered and classified by site and basin. Our results indicated that from the continental species pool, 65.6% are endemic, and about 27% have some sort of official conservation status. These results showed that there are more than a quarter of the continental fish species and include rare, and recovering populations’. On the other hand, the IUCN red list (2015) of threatened species shows 73 records representing 14% of the total, which is not so far from the 11.8% that is officially recognized by the federal government and its institutions. We can conclude that from this analysis, the real diversity center for the neotropical species is in the Caribbean as the entrance from the Amazonia while the Nearctic diversity center for Mexico is the Rio Conchos basin in Chihuahua.