Ontogenetic changes in shell preferences and resource partitioning by the hermit crabs Pagurus hirsutiusculus and P. granosimanus

摘要: Ontogenetic shifts in resource use can serve to reduce mortality and intraspecific competition, but also increase a population's likelihood of extinction. We examined the ontogeny shell type (i.e. snail species) preferences as well usage field 2 sympatric species intertidal hermit crabs, Pagurus hirsutiusculus P. granosimanus, on Vancouver Island, Canada. An experiment examining by 4 crab size classes, spanning broad range juvenile adult sizes, found that both have well-defined throughout benthic life; occupancy at 7 sites was largely consistent with preferences. In addition, changed during ontogeny, terms preferred types diversity were used, which decreased increasing size. Thus, cohort crabs grows from newly settled juveniles full-sized adults, availability suitable shells will depend different species; stages would thus be controlled independent mechanisms. similar-sized mostly ignored used other species, partitioning facilitate coexistence. If limits local abundance these previously suggested, our findings indicate they limited resources produced species). The lack correlation between estimates supports hypothesis granosimanus is factors.