Allometry of the box crab Calappa convexa De Saussure, 1853 (Brachyura, Calappidae) in the southeastern Gulf of California

Abstract

Abstract The relative growth of Calappa convexa can be used to identify dimorphism or morphological change related to sexual maturation. The carapace width (CW) against width and length of the propodus of the right and left cheliped were tested to obtain a coefficient of allometry. CW against total wet weight WT values were analysed for length-weight relationships (LWR). Relative growth was analysed by a multi-model approach. Five models were tested and the best was selected due to the greater weight of the Akaike criterion (). Significant differences between sexes were found in CW (, ) and WT (, ). The negative or positive allometry varied according to the morphometric relationship and sex. No real winner model () was observed in the LWR analysis under a multi-model approach. The average model estimated a breakpoint at 118 mm CW in males and 132 mm CW in females.