Epibiosis of Caryophyllia cf. smithii (Scleractinia: Caryophylliidae) on Paromola cuvieri (Decapoda: Homolidae) in the Ionian Sea

The carrying behaviour of Homolid crabs is well known. They hold sponges, ascidians or other objects on their carapace by means of the last pair of modified pereopods. Furthermore, the crab exoskeleton can represent a hard substratum for the settlement of planktonic larval stages of other organisms. This paper reports the observation of cup corals, Caryophyllia cf. smithii, epibionts on specimens of Paromola cuvieri from the Ionian Sea. The coral polyps were mainly distributed on the dorso-lateral surface of the crab and around the buccal region, probably in order to exploit the water current produced by the maxillipeds, but were also observed on walking legs. Crabs also carried a high abundance of macroepizoites of various taxa such as hydroids, scyphopolyps, actiniarians, serpulids, and bivalves on the carapace and the pereopods.