A new species of crayfish of the genus Cambarellus (Decapoda: Cambaridae) from central Mexico

Abstract

Previous studies suggested that populations of the genus Cambarellus inhabiting La Laja river could correspond to an undescribed taxon. Morphometric analysis of the variation in 15 body traits and molecular analysis from 5 genetic markers were carried on individuals from such localities and other Cambarellus species. Principal component analyses and multivariate analyses of covariance resulted in the identification of significant differences between the newly proposed species and the rest of the analyzed Cambarellus species. Phylogenetic analyses placed populations from La Laja in a monophyletic clade with a COI minimum genetic distance of 8.4%. Based on these findings, it was concluded that this is a distinct species when compared with the rest of Cambarellus . We present the formal description of Cambarellus ( Cambarellus ) moi sp. nov. In comparison with the rest of species, the new species has a longer cephalon (0.30-0.37 times in total length), longer (0.14-0.10 times in total length) and wider rostrum (0.3-0.53 in rostrum length), and a longer antennal scale (0.60-1.0 in rostrum length). Characteristics such as size and shape of the apical processes of the first pleopod of the form I male can be used to distinguish the new species.