Jan C. Dean

Laboratory and field growth trials were conducted to determine the feasibility of using blue crab (Callinectes sapidus) or Atlantic herring (Clupea harenous) cannery waste as dietary protein substitutes in pelleted rainbow trout (Salmo gairdneri) feeds. In lab and field experiments, triplicate groups of trout were fed 3 nutritionally complete diets: (1) a commercial diet (38.8% protein); or 1 of 2 experimental diets containing either (2) blue crab scrap (35.9% protein) or (3) herring byproducts (33.9% protein). Complete replacement of conventional fish meal as a protein source in rainbow...

The relationship between fish size and the activity of certain liver enzymes was assessed in age I rainbow trout (Salrna gairdneri) from 3 Virginia streams. Total length and body weight of the trout differed significantly among streams. Activity of glutamate dehydrogenase and aspartate aminotransferase also differed significantly among fish in the streams and both were negatively correlated with fish size. Differences in size and enzyme activity probably relate to differential caloric intake of fish in the 3 streams. Condition factor and alanine aminotransferase activity of the trout did...