Sexual dimorphism in the relative growth of the claw weight of adult Chinese mitten crab (Eriocheir sinensis). A generalized least squares approach

Abstract

A total of 493 adult individuals of Chinese mitten crab (Eriocheir sinensis H. Milne-Edwards, 1853) were captured in the Odra estuary (Poland). For each crab, sex was determined and the wet weights of the carapace and of the right claw were measured. We were interested in sexual dimorphism in the relationship between claw weight and carapace weight. Variance heterogeneity was included in the statistical model by generalized least squares fitting. Several variance structures were compared using Akaike information criteria and likelihood ratio tests. The final model showed the presence of significant sexual dimorphism in the relationships between the mean claw weight and the carapace weight and between the variance of the claw weight and the carapace weight. © 2013 Copyright 2013 Unione Zoologica Italiana.