Seasonal Changes in Energy Content and Proximate Composition Associated with Somatic Growth and Reproduction in a Representative Age-Class of Female English Sole

The magnitude of seasonal fluctuations in energy content and proximate composition of ovarian and somatic tissues was estimated for female English sole Parophrys vetulus of a standard size, A 386.7-mm, 6-year-old fish gained 73 g dry weight during the spring and summer but subsequently lost 61 g dry weight or 36% of its peak mass from October to March. Thirty-three percent of the lost somatic mass could be accounted for by an increase in ovary mass. However, analysis of gross chemical composition revealed a disproportionate transfer of materials; 55% of lost body protein, 47% of ash, and 5% of lipids were accounted for by an increase in these constituents in ovarian tissue during sexual maturation.