Sabellariid (Polychaeta: Annelida) reefs as nursery ground for the hermit crab Clibanarius symmetricus (Randall, 1840) on the Amazonian coast of Brazil

ABSTRACT

The present study investigated the structure of the crab Clibanarius symmetricus (Randall, 1840) population found in a biogenic reef formed by the polychaete Sabellaria wilsoni Lana & Gruet, 1989 on the Amazonian coast. The population was sampled over a one-year cycle on a reef located in the mesolittoral zone of a sandy beach. The mean and maximum size of the crabs collected on the reef were smaller than those recorded in other tropical and subtropical coastal habitats, given that most of the specimens collected were immature (undetermined sex juveniles and sexually immature adults). Thaisella coronata (Lamarck, 1816) was the gastropod species whose shells were most occupied by the hermit crabs (70% of the specimens), although the smallest juveniles have used more the shells of other species. The results of the study suggest that C. symmetricus uses the reef as a nursery habitat, with bimonthly peaks in density that reflect recruitment periods. The sexually mature adults appear to use the reef only as a foraging area and, occasionally, as a refuge. The results demonstrated the importance these reefs on the population biology of this species and supports the need for more detailed monitoring studies and conservation actions for these habitats.

KEYWORDS:

• Anomuran crab
• biological reef
• Sabellaria wilsoni
• tropical region

Acknowledgements

We are grateful to the late Dr. André Souza dos Santos for his assistance with the identification of the sabellariids and to Dr. Luiz R.L. Simone (Museu de Zoologia da Universidade de São Paulo) for his assistance with the identification of gastropod species. We thank Wanessa Carvalho for her help with the processing of the samples. Thanks also to Dr. Stephen Ferrari for the language revision of the manuscript as well as to two anonymous reviewers for their comments, which helped us to improve the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (CNPq-Brazil) under grant number 486204/2007 (Universal project). The first author was also awarded scholarships by CNPq-Brazil.