Shell utilization pattern of the hermit crab Clibanarius vittatus (Crustacea, Anomura) in an estuary at São Vicente, State of São Paulo, Brazil

Bruno S Sant'Anna,Alvaro L D Reigada,Cilene M Zangrande,Marcelo A A Pinheiro

doi:10.1590/s0073-47212006000200018

Bruno S Sant'Anna, Alvaro L D Reigada + Show 2 more

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https://doi.org/10.1590/s0073-47212006000200018

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Abstract

We evaluated the gastropod shell utilization pattern of the hermit crab Clibanarius vittatus (Bosc, 1802) at Pescadores Beach in São Vicente, State of São Paulo, Brazil. Specimens were collected monthly from May 2001 through April 2003, in the intertidal zone at low tide. The crabs were weighed and their carapace shield length measured. All gastropod shells were identified and had their shell biometric parameters (total length and aperture length) measured (mm) and weighed (g). A total of 2,344 hermit crabs (644 males, 1,594 females, 45 ovigerous females and 61 individuals in intersex), using 13 species of gastropod shells, were collected. Stramonita haemastoma (Linnaeus, 1767), Cymatium parthenopeum (Von Salis, 1793) and Achatina fulica (Bowdich, 1822) comprised over 98% of all the shells. Male and intersex crabs were significantly larger than the females. This size difference strongly influenced the shell utilization pattern, principally in A. fulica, which has the largest shell size, that was only used by males and intersexual individuals of C. vittatus. Cymatium parthenopeum was the only shell species that showed a high determinant coefficient in all the biometric correlations evaluated. The high abundance of S. haemastoma shells and a strong correlation between crab size and shell aperture length established by a significant determination coefficient, indicated that C. vittatus uses this species as the principal resource for shell occupation at Pescadores Beach.

Highlights

IntroductionO objetivo do presente estudo foi avaliar a utilização de conchas de gastrópodes por Clibanarius vittatus (Bosc, 1802), na Praia dos Pescadores, em São Vicente (SP), Brasil
The availability of shells is the most important parameter reported in previous studies (ORIANS & KING, 1964; NEGREIROSFRANSOZO et al, 1991; PINHEIRO et al, 1993; TURRA & LEITE, 2001), and is the main factor limiting populations of hermit crabs (PROVENZANO, 1960; BOLLAY, 1964; REESE, 1969; HAZLETT, 1970)
Shells of S. haemastoma showed the highest percentage of occupation by crabs in all size classes, except in the first class (2.5-3.5 mm), probably due to the low number of individuals collected (Fig. 1)

Summary

Introduction

O objetivo do presente estudo foi avaliar a utilização de conchas de gastrópodes por Clibanarius vittatus (Bosc, 1802), na Praia dos Pescadores, em São Vicente (SP), Brasil. As for other hermit crab species, the wide geographical distribution of Clibanarius vittatus (Bosc, 1802) is explained by its high tolerance to unfavorable environmental conditions due to use of gastropod shells to protect its fragile abdomen (REESE, 1969). Hermit crabs usually have specific preferences for gastropod shell species (REESE, 1962; ORIANS & KING, 1964; BERTNESS, 1980). This preference is associated to shell architecture and size (CONOVER, 1978). The purpose of the present study was to evaluate the pattern of gastropod shell use by C. vittatus, and to verify the most important biometric characters for shell selection

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