Feeding Activity Patterns and Carrion Removal by Terrestrial Hermit Crabs at Enewetak Atoll, Marshall Islands

Terrestrial hermit crabs (Coenobita spp.) were observed feeding on a variety of food items corresponding with observations on the genus worldwide . A field experiment was conducted which examined (1) the feeding activity of Coenobita in two habitats and (2) their potential impact on the removal of carrion and on the colonization of carrion by fly maggots. Habitat and time of day influenced the size and species of Coenobita feeding. Large C. perlatus fed only at night and had the greatest impact on the carrion. Although small Coenobita had little effect on the carrion, their feeding activity did reduce the number of fly maggots in the carrion. The scavenging activity of hermit crabs may serve a useful role on inhabited islets. The rapid removal of carrion would reduce potential fly breeding sites

Patterns of Shell Resource Utilization by Terrestrial Hermit Crabs at Enewetak Atoll, Marshall Islands

Patterns of gastropod shell utilization by Coenobita perlatus and C. rugosus were investigated on three islets of Enewetak Atoll, Marshall Islands. Habitat, hermit crab size, and hermit crab species all influenced the utilization of shells by Coenobita. Small crabs ( < 8mm carapace length) used 63 shell species, while large hermit crabs ( > 19mm) used only two species. Coenobita perlatus occupied long, narrow shells (e.g. , Rhinoclavis) more frequently than C. rugosus. By contrast, C. rugosus used shorter shells (e.g., Nerita) more frequently. Reproduction of C. rugosus, both the percentage of ovigerous females and fecundity, was not influenced by the shell species occupied

Distribution Patterns of Terrestrial Hermit Crabs and Enewetak Atoll, Marchall Islands

Habitat utilization, population structure, and activity were investigated for members of the family Coenobitidae on three islets at Enewetak Atoll, Marshall Islands. Small Coenobita perlatus ( < 8.0-mm carapace length) were more abundant in the beach habitat than medium-size (8-l9-mm carapace length)C. perlatus, C. rugosus, C. brevimanus, or Birgus latro. Large C. perlatus (2: 20-mm carapace length) were present on the beach only at night and engaged primarily in reproductive behavior. Coenobita rugosus on the beach at night were generally females which either had recently released their eggs and larvae into the lagoon or had eggs ready for hatching on their pleopods. The size at maturity was much smaller for the C. perlatus population on Bokandretok as compared with populations on Ikuren and Mut. The scarcity of medium-size individuals may result from a scarcity of suitable Turbo shells