The Colonization of Artificial Crevices by Marine Invertebrates

Abstract

The crevice fauna may be divided into four main groups: permanent inhabitants confined to the crevice habitat; permanent inhabitants that also exist in similar protested habitats elsewhere; temporary inhabitants occupying the crevice during their juvenile stages, and foragers that use the crevice throughout their adult life as a shelter. When artificial crevices are set out in the environment they are first occupied mainly by foragers and juveniles. The permanent crevice fauna appears later or even, as in the case of many obligatory forms, not al all within the period of 2 years of the experiments. The slow colonization of artificial crevices by permanent crevice species is attributed partly to their inefficient dissemination and partly to the long time required for the formation of crevice deposits suitable for invasion by these more specialized forms. The crevice fauna did not develop in artificial crevices exposed in a sheltered muddy environment, because the crevices quickly became filled with mud and were then unsuitable to all but a few species.