Shell Disease among Red Crabs Inhabiting Submarine Canyons of the New York Bight

摘要

The study was undertaken to assess the extent and severity of shell disease among New York Bight deepsea red crabs (Geryon quinquedens). The shell disease syndrome is a contagious condition which occurs among many crustacean species and habitats, and is caused by a variety of chitinoclastic bacteria and fungi. Crabs from the three canyons sampled, Hudson, Block, and Atlantis, had overall disease prevalences of 92,92, and 86 percent, respectively. Of the Hudson Canyon specimens, 13 percent were rated as moderately to severely diseased. The appearance of the shell disease ranged from very small black spots to large grey to black patches covering a substantial portion of the carapace. Two explanations are offered to explain how shell disease might spread in this manner: (1) the protective epicuticle covering corresponding body parts on each side of the animal are equally abraded by sediment, rocks, or other body parts, exposing the chitinous layers beneath to chitinoclastic microorganisms; and (2) these microorganisms may gain access to the underlying chitinous layers of the integument through pores which are arranged bilaterally.