A geometric morphometric analysis of two sympatric species of the family Aeglidae (Crustacea, Decapoda, Anomura) from the La Plata basin

The crustaceans of the family Aeglidae are endemic to the southern regions of South America. Geometric morphometrics was used to assess differences in size and shape between two sympatric species of the family, A. uruguayana and A. platensis, Eleven landmarks on the dorsal region of the cephalothorax were recorded on 57 adult specimens. Interspecific and intraspecific differences in size and shape were analyzed through univariate and multivariate statistics performed on the generalized pro-crustes analysis aligned coordinates. Shape differences between A. uruguayana and A. platensis, and between mates and females, were readily identifiable along the first and the second relative warp. MANOVA showed these differences to he significant. Intraspecific comparisons also revealed a significant Sexual dimorphism in cephalothorax shape. Two-way ANOVA on centroid size did not show any significant difference between species nor between sexual.