Dietary lysine effects on stress-related mortality of the marine shrimp, Penaeus stylirostris

Studies with semi-synthetic diets revealed that dietary lysine reduced the effects of an un-identified disease of penaeid nervous systems. Four semi-synthetíc diets were prepared with different levels of dietary lysine as the sole variable.

Heavy treatment-related mortality resulted after the first weight period. Subsequent stress exercises resulted in a consistent mortality pattern which was inversely related to lysine levels in the diet. Microscopic examination of the dead shrimp revealed neural lesions in all test treatments but in greatest incidence and severity in shrimp fed the lowest lysine level.