Energetics of Sablefish, Anoplopoma fimbria, under Laboratory Conditions

We measured respiration, growth, ingestion, and excretion rates for sablefish, Anoplopoma fimbria, collected off southern California at a depth of 500 m and maintained in the laboratory. We also measured the water, protein, and lipid content of white skeletal muscle in both laboratory-held and field fish. Sablefish fed a large ration (14% of wet body weight) every 7–10 d showed growth rates two to three times higher than known growth rates for field fish. On a reduced ration (4% of wet body weight) sablefish grew at rates similar to field fish, but white muscle composition varied significantly from field fish. Oxygen consumption rates under constant temperature conditions showed a decrease in the weight-specific oxygen consumption rates with increase in body weight, ranging from routine metabolic rates of 195.8 mg O 2 ∙kg −1 ∙h −1 for a 0.25-kg fish to 60.8 mg O 2 ∙kg −1 ∙h −1 for a 2.78-kg fish. Based on measurements of respiration and excretion, sablefish were estimated to have 162 d of energy stored in the body lipids and did not show signs of starvation stress with food deprivation up to 6 mo in the laboratory. Energy allocation shows very slow growth rates, low conversion efficiencies, and low metabolic rates as adjustments made to large, infrequent meals.Key words: physiological responses, benthopelagic fish, growth, metabolic rate, respiration, excretion