Reproductive behavior of intertidal hermit crabs (Decapoda, Anomura) in southeastern Brazil

Abstract

The reproductive behavior of four intertidal hermit crab species [Clibanarius antillensis Stimpson, 1859, C. sclopetarius (Herbst, 1796), C. vittatus (Bosc, 1802), and Pagurus criniticornis (Dana, 1852)] was studied in São Sebastião Channel, southeastern Brazil. The overall behavior followed previous descriptions for Diogenid and Pagurid hermit crabs but some particular differences were recorded. Male to male agonistic encounters over females and guarding behavior were more common to C. sclopetarius, C. vittatus, and Pagurus criniticornis. During guarding, males clearly grasped females' chelipeds, eyestalks, and the margins of their shell apertures. This oblique guarding and, simultaneously, accessing behavior (OGAP) has never been described for hermit crabs and was more common to C. sclopetarius and C. vittatus. Pagurus criniticornis did not present the typical jerking behavior of pagurids. Multiple copulations between a single pair were recorded in all species while in only one occasion a female of C. vittatus was observed copulating with two males. In the post-copulatory behavior males held females for some time and, after that, they were left inactive and sometimes totally to partially buried in the substrate. In mating pairs of all species males were larger than females and two individuals (out of 23) of C. antillensis, one (out of 5) of C. sclopetarius and one (out of 3) of C. vittatus, which courted successfully as males fertilizing females' eggs, were demonstrated to be intersex, with both male and female gonopores.