Epibionts and intermoult duration in the crab Bathynectes piperitus

Abstract

The patterns of epibiosis on the portunid crab Bathynectes piperitus were studied off S Namibia. Patterns of distribution of the hydroid Stegopoma plicatile, the polychaeta Spirorbis patagonicus, the pedunculate cirriped Poecilasma kaempferi and the bryozoan Nolella annectens. The hydroid occurred preferentially on the anterior part (46.9%) of the carapace, whereas the cirriped was found most commonly on the posterior (45.7%). The polychaete was more common on the inferior parts (53.1%) as was the bryozoan (80.3%). The relationship between crab size and the number of polyps (hydranths), the number of colonies and the number of gonothecae of S. plicatile were also analyzed. Based on the identification of three cohorts in both the hydroid and cirriped populations, and taking into account their probable age, a minimal time for the intermoult period can be defined. The process of colonization is continuous on all sizes of adult crab. -from Authors