The sublethal effects of a polychlorinated biphenyl (Aroclor 1254) diet on the Atlantic cod (Gadus morhua).

The effects of diet levels of 1, 5, 10, 25 and 50 micrograms Aroclor 1254/g on the Atlantic cod Gadus morhua were determined after a feeding period of 5 1/2 months. Altered steroid biosynthetic patterns in vitro were observed in the testes and head kidneys (adrenal homologue) of the fish that were fed various levels of PCB in vivo. Histological examination of tissues revealed abnormalities in the testes, gills, and livers of the PCB-fed fish. Various testicular abnormalities including slight-to-marked derangement of lobules, hyperplasia of lobule walls and disintegration and/or fatty necrosis of spermatogenic elements were observed in the testes of PCB-fed fish. Hyperplasia of the epithelial layer of the secondary lamellae was observed in the gills of fish on the 5 to 50 micrograms Aroclor 1254/g diet. Fatty degeneration was observed in the livers of all PCB-fed fish. The PCB content of testes, livers and head kidneys were directly proportional to the level of Aroclor 1254 in the diet. It is apparent that sublethal levels of PCB have a detrimental effect on the physiology of the Atlantic cod.