Genetic variation in native and introduced populations of the red swamp crayfish Procambarus clarkii (Girard, 1852) (Crustacea, Decapoda, Cambaridae) in Mexico and Costa Rica

The genetic variation among nine populations of the red swamp crayfish Procambarus clarkii was examined using partial sequences of the mitochondrial COI gene. Three populations (Illinois and Louisiana, United States and northern Coahuila, Mexico) represented the native range and six populations came from areas where the species has been introduced (central Coahuila, southern Nuevo Leon, Durango, Chihuahua and Chiapas, Mexico, and Cartago, Costa Rica). A 689 bp fragment was amplified from 37 samples. Uncorrected genetic distances among sequences were p = 0 to 0.02031 and 12 haplotypes were found. A phylogenetic reconstruction shows that the three populations from the native range remain very similar to each other and some introduced populations can be directly associated to one of them. The populations from Nuevo Leon, central Coahuila and Costa Rica were the most divergent ones. Overall the genetic variation found in P. clarkii in both native and introduced populations is low.