Behaviour 2019
The Role of Carapace Coloration in Mate Preference in an American Fiddler Crab
Diogo Jackson de Silva, Marília Fernandes Erickson, Daniel Marques de Almeida Pessoa. UFRN, Natal, RN, Brazil

The visual ability to identify conspecifics and to differentiate them brings an adaptive advantage that increases reproductive success. Body color signals can inform not only to which species an animal belongs, but also its sex, reproductive status, and partner quality. Fiddler crabs are colorful and display distinct colorations in their claw and carapace. In previous studies, female American fiddler crabs were able to distinguish males based on claw coloration and used that information for mate choice. However, we still do not know if male carapace also plays a role in communication. Thus, this study aims to establish if females can distinguish males based on the color of their carapace. Females were subjected to two-choice discriminations, between conspecific and heterospecific males, in which carapace simulated conspecifics’ or heterospecifics’ color. We found that females prefer males (conspecific or heterospecific) that match their own carapace color. The same trend was not found for males’ hypertrophied claw coloration. This is the first study to demonstrate that carapace coloration of fiddler crabs is crucial for interspecific recognition.