Carol A. Lemm

Influence of Varying Lipid Concentrations with Two Protein Concentrations in Diets for Rainbow Trout (Salmo gairdneri)

Abstract The sparing action of dietary lipids on protein observed in rainbow trout was demonstrated in practical trout diets. The digestible energy content of a diet in relation to the percent of dietary protein (DE/P ratio) can be a determining factor in the protein requirements of rainbow trout. The DE/P ratio of the diet was positively correlated with protein retained (%) by the fish but with no other factors measured in this study. Growth, feed conversion, and daily length increment were all correlated with the energy content of the diet. Increased amounts of digestible energy in the diet also enhanced the efficient use of that energy. Diets containing high percentages of fat produced fatter fish with lower percentages of protein.

Benzocaine as an Anesthetic for Striped Bass

Abstract Benzocaine was tested as an anesthetic on juvenile and mature adult striped bass (Morone saxatilis). Concentrations of 55 mg/L at 22°C to 80 mg/L at 11°C effectively anesthetized fish in about 3 min. Recovery was more rapid as temperature increased. Fish survived concentrations of twice the effective concentration and exposure times up to 60 min at the effective concentration. Striped bass required higher concentrations for anesthetization than had been previously demonstrated for salmonid fishes, but safety margins for both concentration and exposure time were wider than for the salmonids.

Differential Performance of Four Strains of Rainbow Trout Reared under Standardized Conditions

Abstract Four strains of rainbow trout were evaluated for average weight gain, feed conversion, daily length increment, and percent mortality. Significant differences were found to exist between certain strains for all characteristics measured. The rank of the four strains in rate of growth was the same whether the fish were fed a diet high in plant protein or high in animal protein, suggesting that genetically distinct strains of rainbow trout may exhibit the same relative growth rates, irrespective of diet.

Growth and Survival of Atlantic Salmon Fed Semimoist or Dry Starter Diets

Abstract Growth and survival were compared for first-feeding fry of Atlantic salmon (Salmo salar) fed a closed-formula commercial preparation, BioDiet, or U.S. Fish and Wildlife Service high nutrient density diets 398 or 406 for 14 weeks. Growth of fry fed BioDiet for 2, 3, 4, or 6 weeks from first feeding and then fed diet 406 for the rest of the 14-week study was also examined. Growth was fastest in fish fed exclusively diets 398 or 406 for 14 weeks, or BioDiet for 2 weeks followed by diet 406 for 12 weeks; survival was about 68, 82, and 92% respectively, for these three groups. These results indicate that in Atlantic salmon fry growth was most rapid and survival highest among fish fed BioDiet for the first 2 or 3 weeks followed by diet 406.

Movement of Underyearling Walleyes in Response to Odor and Visual Cues

Abstract Underyearling walleyes, allowed to move freely in a Y-shaped chamber into which various substances were added to one arm or another, were attracted to sodium chloride, sucrose, glutathione, vitamin B12, betaine, arginine, Daphnia slurries, some fish slurries, washings from live Daphnia and Artemia, and some commercial fish foods. They avoided cysteine, glycine, glycine-betaine, Artemia slurries, some fish slurries, and fish mucus; and showed little reaction to valeric and caproic acid, and some commercial fish foods. Tests of visual response, in which beakers containing live food organisms were placed in the arms of the chamber, indicated that walleyes respond strongly to the movement of food organisms. Walleyes usually surrounded the beakers containing live food organisms and repeatedly struck the glass. They were attracted more strongly to Artemia than to Daphnia. Results indicate that odor plays an important role in movement of walleyes to food and that there is a potential for attracting inte...

Tricaine Used to Separate Phase-I Striped Bass with Uninflated Gas Bladders from Normal Fish

Abstract Tricaine (MS-222) was used to separate striped bass (Morone saxatilis) with uninflated gas bladders from normal fish. Pond-reared, phase-1 striped bass (19–71 mm total length) were anaesthetized in a 12.5‰ saltwater solution containing 110–123 mg MS-222/L. Fish with inflated gas bladders were neutrally buoyant or floated, whereas fish with uninflated gas bladders remained on the bottom. Dissection of buoyant and nonbuoyant fish indicated the procedure was 90–100% accurate. Eliminating fish with uninflated gas bladders will improve efficiency and quality of phase-11 production.

Development of a practical diet for juvenile striped bass

Abstract We formulated four diets that simulated the amino acid profiles of eggs of striped bass Morone saxatilis, carcasses of larval striped bass, eggs of rainbow trout Oncorhynchus mykiss, or nauplii of Artemia salina; a fifth diet contained a high concentration (33.6%) of shrimp meal. These diets were fed to juvenile striped bass for 14 weeks. Striped bass grew best when fed diets with an amino acid pattern that simulated the patterns of rainbow trout eggs or Artemia salina. Fish fed these two diets grew as well as, and had carcass compositions and protein efficiency ratios similar to those of, control fish fed the federally specified ASD2-30 salmon diet. No histological or morphological abnormalities were noted. These two diets, which have potentially lower production costs and contain slightly less protein than ASD2-30, may be used as prototype diets specifically for striped bass. Through further minor refinements, the diets could be used in production hatcheries.

Growth and survival of Atlantic salmon fed various starter diets.

Abstract Growth and survival were compared for groups of first-feeding fry of Atlantic salmon (Salmo salar) fed various commercially available and experimental starter diets. In two separate 8- to 9-week studies, survival was highest (more than 90%) in fish fed a semimoist closed-formula commercial diet (BioDiet). In one study, fish grew fastest on BioDiet, whereas in the second study they grew fastest on a liver-supplemented diet. Some diets were not eaten by the fish, resulting in little growth and less than 40% survival.

Articles: Lack of Dietary Effects on the Timing of Smoltification in Atlantic Salmon

Abstract Six commercially available diets varying in lipid, protein, water, ash, and carbohydrate contents were fed to Atlantic salmon (Salmo salar) for 2 years to determine if diet affected smoltification. Each month, from March to September of the second year, sampled fish were exposed to 33‰ seawater for 24 h to determine smolt readiness, defined as the ability to maintain water and salt balance in a seawater challenge. Regardless of diet, Atlantic salmon were able to regulate plasma sodium and chloride ions (smoltify) only during early May. It is unlikely that hatchery managers could effectively use high-energy diets to control the time of smoltification in Atlantic salmon.

Growth of tiger muskellunge fed different amounts of protein at three water temperatures

Abstract Growth rates of tiger muskellunge (muskellunge Esox masquinongy ♀ x northern pike E. lucius ♂) fed diets containing 35, 45, or 55% crude protein for 5 weeks at 17, 20, or 23°C were compared. Fish fed diets containing 45 or 55% protein grew faster at all temperatures than those fed 35% protein. Growth of tiger muskellunge fed a diet containing either 45 or 55% protein did not increase significantly at optimum growth temperatures (20 or 23°C). At 17°C, below the optimum temperature range, growth did increase when the percentage of protein in the diet was increased.