Ecological evaluation of local extinction: the case of two genera of endemic Mexican fish, Zoogoneticus and Skiffia

摘要: The Goodeidae is a family of endemic fish from central Mexico. Populations several species are declining in the wild and two have been reported extinct; Skiffia francesae Zoogoneticus tequila. Both were native to just one locality Ameca basin. It difficult infer causes extinction, since limnological data Teuchitlan prior extinction events not available, there no replicate populations. As an alternative approach, we explored potential links between key environmental variables local any genera (four spp. spp.). In 14 localities known harbour populations at least six focal species, conducted surveys rainy dry season, quantified population densities introduced fish. addition, concentration agricultural pollutants water mud samples taken every season. We found that all face some conservation threat, but also discovered extremely small reputedly extinct tequila; contrast, was found. Eutrophication habitat fragmentation appear be main threats with exponentially reducing size driving into refuges where they stochastic extinction.