Incidence of shell disease in shrimp is as high as 30% in certain localities in the New York Bight. Gross examination and histopathological preparations revealed cracking and pitting of the exoskeleton, common characteristics of crustacean shell disease, followed by necrosis of underlying tissue. Aquarium studies, which included tests of the effects of an antibiotic, indicated a possible infectious etiology. The disease may be related to pollution of the habitat by organic wastes including cellulose.