Mouthparts of the crab Goniopsis cruentata (Latreille, 1803) (Decapoda, Brachyura, Grapsidae): Morphological variations associated with environment, sex and stage of development

Individuals and populations can display variations in distinct aspects of their life histories, which could be reflected in their morphological characteristics. This study analyzed the mouthpart morphology of the crab Goniopsis cruentata in relation to environment, sex and stage of development. Our results indicate differences in the number of setae between developmental stages and environments, as well as the interaction between developmental stages and environments. There were no differences in setae types between stages, sexes or environments. There were differences in the shape of the ischium between adults and juveniles, with a more homogeneous ischium in juveniles than adults. We also found differences in food content between developmental stages, as well as an interaction between developmental stages and environment. Our results support an association between diet and morphology of mouthparts in G. cruentata, and that these apparatuses vary according to ontogenetic development and the environmental conditions that species are exposed to. These associations should be considered in studies that use these characteristics to verify morphological responses to environmental variations.