Establishment of the exotic invasive redclaw crayfish Cherax quadricarinatus (Von Martens, 1868) in the Coastal Plain of San Blas, Nayarit, SE Gulf of California, Mexico

The establishment of the redclaw crayfish (Cherax quadricarinatus) populations was investigated in the coastal plain of San Blas, Nayarit State, Mexico. Two sampling expeditions were conducted along the agricultural irrigation channels and the surrounding estuarine systems in the study area in December 2014 and December 2015. A total of 121 specimens were collected during the first sampling. They had 1:1.88 male:female ratio. Three hundred fourteen (314) individuals were collected in the second expedition. the male:female ratio was 1:1.27. C. quadricarinatus has a great ability to colonize, invade and survive a wide range of environmental conditions in aquatic ecosystems, representing a threat to biological diversity. This species has the potential to replace the native crayfish species that significantly sustain the local fisheries, affecting and limiting their distribution and abundance. This has probably affected diversity, population structure and symbiotic relationships of functional groups in this aquatic ecosystem.