Comparative studies of reproductive behavior in mantis shrimps and fiddler crabs

Abstract

Comparative ethological studies of closely related species can place into clear perspective the functions of behavioral traits as species diverge and adapt to different environments. In this paper we contrast the reproductive behavior of species within two crustacean groups: the mantis shrimps (stomatopods) and the fiddler crabs (genus Uca). For the stomatopods, we identify probable selective relationships between features of species' ecology and their mating systems. Population density, the kind and availability of shelters in which these shrimps live, the intensity of predation and spawning cycles all play important roles in molding reproductive behavior in this group. Associations between the ecology and mating systems of fiddler crabs have been discussed recently elsewhere. Here we focus on a comparative analysis of sexual communication in these crabs. A study of competitive courtship signaling and mate choice in the fiddler crab Uca beebei has shown that certain male courtship signals are highly attractive probably because they exploit female sensory-response systems that have been molded by selection for escape from predators. Interspecific comparison of male courtship displays and the responses of females to these displays suggest that sensory exploitation may play an important role in the evolution of sexual signals in the genus. Comparative studies have advanced our understanding of how natural and sexual selection affect the reproductive behavior of both stomatopods and fiddler crabs. © 1991 by the American Society of Zoologists.