The Pylochelidae differ from the other hermit crabs by the complete segmentation of the abdomen and the presence of paired appendages on each of its segments. They do not usually inhabit gastropod shells, but dwell in decayed pieces of wood, stones, tusk-shells, or living sponges. A
recent revision, founded on most of the previously recorded specimens and on a large unidentified collection, increased the number of known species from 16 to 39, and the genera from 5 to 7. Two new subgenera have been established, and the family divided into six subfamilies. This paper deals
first with the eco-ethological characteristics of the different taxa. According to their dwelling, genera and subgenera can be classified, as a whole, as xylicolous, petricolous, tusk-dwellers, spongicolous, with a few specifical or individual exceptions. In connection with the habitat, adaptive
features have been described: opercular structures, boring “rasp,” stridulating apparatus… The Pylochelidae are present in the Indo-West Pacific (36 species or subspecies in 6 genera), and in the NW Atlantic (4 species in 3 genera). Two genera only, belonging to the sole
non monotypic subfamily, provide a biogeographical link between the two areas. In I-W.P., the family is known from the SW Indian Ocean to Japan, Kermadec Islands and New Zealand. Indonesia, with 14 species and 5 genera appears as a center of dispersion and diversification. Japanese endemism
is noteworthy: one genus and six of the seven species have not been reported elsewhere. The probable relation between the availability of dwelling material and the geographical distribution is also discussed. The vertical distribution extends from 30 to 1,570 m, but the group is mostly represented
between 200 and 500 m, where 28 species are living.
The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.