Anthony C. Ostrowski

Effect of Rearing Tank Background Color on Early Survival of Dolphin Larvae

Abstract The effect of experimental tank background color on early survival rates of dolphin larvae (Coryphaena hippurus) was examined to determine the survival rates of 7-d-old fish fed varying rotifer concentrations in different experimental systems. Fish were stocked into unpainted (tan) or painted (glossy black) fiberglass tanks and fed rotifers at densities of either 5, 10, 15, 20, or 50 animals/mL of water. Overall survival of larvae averaged 50% in black tanks and 25% in uncolored tanks. When directly compared, black tanks improved survival rates 130% over tan tanks. Survival was affected by rotifer stocking density in experiments with tan tanks and was maximum when larvae were fed 20 rotifers/mL. Survival was not affected by densities between 5 and 20 rotifers!mL in black tanks. It is concluded that the use of black tanks greatly enhances early survival rates of dolphin larvae fed rotifers. The effect is likely related in part to the contrast between feed items and the background tank color. This ...

Economics of offshore aquaculture of Pacific threadfin (Polydactylus sexfilis) in Hawaii

Abstract A feasibility study for an offshore Pacific threadfin ( Polydactylus sexfilis ) cage production system was conducted for Hawaii. The hypothetical six-cage system was based on the bio-technology requirements of and productivity demonstrated by the Hawaii Offshore Aquaculture Research Project (HOARP). At a farm-gate price of US

Influences of Anabolic Hormone Treatment and Dietary Protein: Energy Ratio on Condition and Muscle Deposition of Rainbow Trout

4.00/lb, several areas of efficiency improvements are required in order to reach profitability based upon current model inputs for the six-cage system in Hawaii. The total cost of production is estimated at US

Dietary Androgen-Estrogen Combinations in Growth Promotion in Fingerling Rainbow Trout

3.97/lb for the production system projected to yield 914,271 lb of Pacific threadfin annually. The largest costs contributing to annual operating expenses of US

Economics of milkfish (Chanos chanos) production in Hawaii

3,626,556 were feed (30%), labor (17%), stocking (12%) and shipping (11%). Based on sensitivity analyses, increased stocking densities, survival rates and average growth rates have the largest potential for reducing production costs. HOARP is among the first reported successful deployments of a fully submerged cage system in the United States. This study details the technological requirements, associated costs and reports recommendations for farm management in light of the financial strains of full-scale commercial deployment.

Size Economies of a Pacific Threadfin Polydactylus sexfilis Hatchery in Hawaii

Abstract The effects of dietary 17a-methyltestosterone (MT) and protein-to-metabolizable energy (P:ME) ratios on the weight gain of individual body components and their relative contribution to the condition factor (K) were examined for juvenile rainbow trout (Salmo gairdneri). Five semipurified isocaloric diets (390 kcal/100 g dry ingredients) containing 80, 100, 120, 140, and 160 mg protein/kcal ME were prepared with and without 2.0 mg MT/kg of diet and fed to 5-g rainbow trout for 8 weeks. At the end of the experiment, fish were weighed and measured, and then dissected or cooked to obtain individual wet weights of the head, fins, skin, muscle, carcass bone, viscera, and rib section. Steroid treatment increased the weight gain of muscle tissue in direct proportion to the increase in body weight gain. Linear bone growth was enhanced with treatment, but the rate of increase did not keep pace with the rate of weight increase of the rest of the body. This accounted for a lowered percentage bone weight gain ...

Patchiness Formation and Development of Schooling Behavior in Pacific Threadfin Polydactylus sexfilis Reared with Different Dietary Highly Unsaturated Fatty Acid Contents

Abstract Eight semipurified diets containing various combinations (totaling 2.0 mg/kg diet) of the androgens 17α-methyltestosterone (MT) and 5α-dihydrotestosterone (DHT) and the estrogen estradiol-17β (ES) were fed to four replicate groups of rainbow trout (Salmo gairdneri) fingerlings (initial weight = 0.7 g) for 10 weeks to determine relative growth-promoting effectiveness. Fish fed MT alone or in combination with DHT gained 27.3% more body weight than controls (P 0.20) on body weight. Feed conversion (weight of feed fed/fish weight gained) and average weight gain were recorded over bimonthly periods to examine the effects of treatments on these characteristics. Methyltestosterone enhanced growth (P < 0.05) without changing feed utilization. Decreases (P < 0....

Effect of 17α‐Methyltestosterone Treatment and Withdrawal on Growth and Dietary Protein Utilization of Juvenile Rainbow Trout Fed Practical Diets Varying in Protein Level1,2

Abstract Economic evaluations of commercial milkfish (Chanos chanos) growout systems were made based on current Hawaiian fishpond, pond and tank culture techniques in Hawaii. Based on the observed practices of milkfish culture as a secondary or tertiary crop, capital costs and several operating costs were pro‐rated to accurately depict current farm practices. For a target harvest weight of 0.80 lb, the study estimates the total production cost for milkfish production at

Evaluation of Soybean Meal‐Red Blood Cell Coextruded Feed Ingredient in Diets Fed to Rainbow Trout Oncorhynchus mykiss

3.31/lb for the pond system,

Changes in Dietary Protein to Metabolizable Energy Needs of 17α-Methyltestosterone Treated Juvenile Rainbow Trout1,2

3.81/lb for the tank system and