Threats and Conservation Status of Freshwater Crayfish (Decapoda: Cambaridae) in Mexico

Abstract

Freshwater crayfish is a group of freshwater crustaceans especially diverse in North America and particularly in Mexico, where previous works have been identified it as a highly imperiled fauna. As a first step aiming to preserve their diversity, it is important to identify the factors impacting their populations. In this chapter, we present an overview of the main threats observed during recent surveys in habitats of the native species that occur in Mexico and propose a categorization of their conservation status according to IUCN criteria. Introduced species, freshwater extraction, pollution, and fragmentation or isolation of populations are identified as the major drivers of decline for this fauna. The extent of such threats make Mexican crayfish fauna one of the most imperiled invertebrate groups worldwide. One species is extinct in the wild, and more than half of the species need conservation measures (56%) mostly a result of their small geographical range, and the sensitive nature of their habitats, which are also highly disturbed. Of the 60 species known, 24.1% are assessed as critically endangered, 13.8% as endangered, and 22.4% as vulnerable. Most of these species need actions to revert the identified negative trends and human-mediated impacts to ensure their long-term survival.