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The article focuses on a study concerning the shell disease called epizootic shell disease (ESD) which has been detrimental to the lobster fishery. The study says that shell disease of H. americanus in Atlantic Canada is extremely rare, and the three degrees of shell disease severity have been observed in lobsters from Atlantic Canada.

The eastern oyster, Crassostrea virginica (Gmelin), is both an important component of our estuaries and an important farmed food animal along the east and south coasts of the United States. Its populations have been significantly diminished in the wild due to decades of overfishing beginning in the 1890s. Unfortunately, in 1950, a new disease in eastern oysters caused by the protistan agent, Perkinsus marinus, was identified. The disease, resulting from infection with this protozoan, leads to high mortality of both wild and cultured eastern oysters. Current restoration efforts are hampered by the disease, as is the aquaculture of this economically important food. The parasite infects hemocytes and causes hemolytic anemia and general degeneration of the tissues, leading to death. Ongoing research efforts are attempting to develop oysters resistant to the disease. Transport regulations exist in may states. Infection with P. marinus is listed as a reportable disease by the World Health Organization. [ABSTRACT FROM PUBLISHER]

Blue crabs affected with shell disease displayed a wide array of pathologies in response to this very common affliction. Grossly, shell disease lesions most commonly presented as variably sized brown to black foci. Such lesions ranged from very small (1 mm[sup 2]) to locally extensive (up to 200 mm[sup 2] in area). The larger of the melanized lesions sometimes appeared ulcerated. The most severe lesions observed (Pamlico River shell disease-PRSD) resulted in loss of up to 25% of the entire carapace. A diverse bacterial flora consisting of aeromonads, vibrios and five other genera were isolated as the predominant organisms from shell disease lesions. Fungi were rarely observed in larger lesions. Protozoa and algae were also rarely observed on the surface of some lesions. Histologically, lesions ranged from mild erosion of the epicuticle and outermost layers of the calcified endocuticle to more extensive endocuticle erosion with accompanying inflammation. In the most severe cases, there was total loss of the endocuticle and epidermis, with pseudomembrane formation, intense haemocyte infiltration, and involvement of adjacent viscera. There was no apparent relationship between the size of gross lesions and their histological severity (as defined by the extent of tissue damage), suggesting that gross examination of shell disease lesions is not a reliable method for assessing the damage to affected blue crabs. [ABSTRACT FROM AUTHOR]

Investigates epizootic lobster shell disease in Homarus americanus, or American lobster using scanning electron microscopy. Role of bacteria in the progression of lesion development; Bacterial types observed on both healthy and infected animals.

The expression of cytochrome P450IA1 was examined in hepatic lesions of mummichog (), a small, non-migratory teleost fish collected from a site in the Elizabeth River, VA, heavily contaminated with polycyclic aromatic hydrocarbons (PAH) of creosote origin. Immunoblot (‘Western’ blot) analysis using monoclonal antibody (MAb 1-12-3) to P450IA1 of the marine fish indicated that cytochrome P450IA1 levels in hepatocellular carcinoma and in foci of cellular alteration were 28–85% lower than those of adjacent non-neoplastic tissue. P450IA1-dependent monooxygenase activity, measured as ethoxyresorufin -deethylase (EROD), exhibited a similar trend with EROD activity in lesions being 15–77% lower than activity in non-neoplastic tissue. Immunohistochemical examination of liver sections revealed general low intensity P450IA1-associated staining in hepatocellular carcinoma, exocrine pancreatic tissue, bile ducts and cholangiocellular proliferative lesions. Staining intensity of non-neoplastic hepatic parenchyma varied considerably and was focally distributed. In one case intense staining was observed in an altered hepatocellular focus (putative preneoplastic lesion). The results indicate important similarities in the expression of P450IA1 in neoplasms of fish and mammals and suggest an adaptive response of a wild population to carcinogen exposure. [ABSTRACT FROM PUBLISHER]

Presents information on a study which identified common causes of morbidity and mortality in the cuttlefish populations of the genus Sepia maintained at the Marine Resources Center. Description of Vibrio alginolyticus infection in cultured sepia; Forms of the sepiod inflammatory reaction to Vibrio alginolyticus; Routes of infection.

Looks at bacterial pericarditis, a disease identified in toadfish. When the disease was identified by researchers at the Marine Biological Laboratory's Marine Resource Center; Most characteristic gross lesions identified in the disease; Non classification of the bacterium causing the disease.

Investigated the use of needle biopsy and visual inspection of the gross morphology in determining the reproductive stages of the Atlantic surf clam, Spisula solidissima. Comparison of the staging accuracy of the two methods to histologic staging; Experiments conducted; Results obtained.