Revista Chilena de Historia Natural 79 (4): 481-487, 2006
RESEARCH ARTICLE
Comparative study of shell choice by the southern endemic hermit crab Loxopagurus
loxochelis from Brazil and Argentina
This study aimed to determine the shell choice pattern of the southern Atlantic endemic
hermit crab Loxopagurus loxochelis from two different biogeographic provinces in Brazil and Argentina. Size and shell
species preferences were determined for the two most occupied shell types (i.e., Olivancillaria urceus and
Buccinanops gradatum) in Caraguatatuba region (Brazil) and in Mar del Plata (Argentina). Shell occupation was analyzed
considering the biometric characteristics of shells, the occurrence of shell types, and the preference of the hermit crabs for the most
frequently occupied shell species. Samples were taken using otter trawl in the infralittoral area of both regions and the animals
captured were measured and weighed. Shells were identified, weighed, measured and their internal volume calculated. Experiments
were accomplished in aquaria where the hermit crabs were allocated together with a sufficient number of adequate sized shells. In
laboratory, L. loxochelis from Argentina presented no preference for any of the two offered shell species, while the
specimens from Brazil significantly preferred B. gradatum shells. It was observed that the relation between shell
dimensions and shell weight were the variables that best explained the association between hermit crabs and shells. Considering that
Argentinean specimens are larger than the Brazilian ones we may infer that body size is a relevant factor to explain the observed
differences found in relation to shell type preference.
Key words:
shell preference,
Anomura, Loxopagurus loxochelis
