An integrative approach-using field and laboratory data to characterize shell utilization and selection pattern by the hermit crab Pagurus criniticornis (Paguridae) from Anchieta Island, Brazil

Abstract

Th e aim of this study was to characterize the patt ern of gastropod shell occupation in the fi eld and selection of shell size and type under laboratory conditions by the hermit crab Pagurus criniticornis (Dana, 1852), inhabiting the infralitt oral area of Anchieta Island, São Paulo, Brazil. Hermit crabs were obtained monthly during 1999 by SCUBA diving. For experiments under laboratory conditions, samplings were performed in 2002. Th e hermit crabs occupied 16 species of gastropods shells. Cerithium atratum (Born, 1778) was the most occupied shell (89.31%), followed by Morula nodulosa (4.73%) (Adams, 1845). No diff erence was observed in the patt ern of occupation between males and females. Th e equations that best demonstrated the relationship between hermit crabs and their shells were those that involved Shell Wet Weight (SWW) and Shell Internal Volume (SIV). Th e laboratory experiments were in accordance to the patt ern of occupation observed in the fi eld; the mean value of SAI (Shell Adequacy Index) recorded to the population studied was 1.