Compensatory growth in Alaska yellowfin sole, Pleuronectes asper, following food deprivation

Abstract

During the early spring four groups of sub‐adult Pleuronectes asper were fasted for either 0, 2, 4 or 6 weeks at the beginning of a 12‐week experiment, then fed to satiation to examine their ability to compensate with faster growth after food deprivation. All fish increased their stored energy reserves markedly and at the end of the experiment all four groups had similar body energy content (J g−1), length gains and dry weight to wet weight ratios. The groups of yellowfin sole fed continuously or fasted for 2 weeks gained the most weight, 25 and 24% respectively. Fishes fasted either 4 or 6 weeks exhibited significantly lower weight gains of 16 and 15% respectively over the 12‐week experiment. Because of this disparity in weight gain the total body energy content of the continuously fed fish and those fasted for only 2 weeks increased by approximately 60 vs 46% or 35% for sole fasted for 4 or 6 weeks.The experiment showed P. asper had a limited capacity for compensatory growth. When food was scarce yellowfin sole allocated energy preferentially to growth in length instead of weight. These findings may account for some of the interannual differences in mean length and weight at age for yellowfin sole from the Bering Sea where variations in extent and duration of ice cover and the boreal bottom water delimit the growing season.