Shell disease lesions in both captured and aquarium-reared blue crabs exhibited a similar continuum of damage and severity, ranging from pinpoint, black-pigmented foci to very extensive
lesions with significant shell defects (Figs 1–5). After examining 78 lesions, we divided them into four categories, based upon microscopic appearance. A separate group of lesions comprising crabs
having massive loss of the shell (Pamlico River shell disease, Figs 6 & 7) were described separately.