Physiological and Genetic Aspects of Growth in the Mussel Mytilus edulis. I. Oxygen Consumption, Growth, and Weight Loss

Abstract

Small (S; shell length, 4 mm) and large (L; shell length, 10 mm) Mytilus edulis spat were grown singly in plastic racks in a tidal salt marsh for 72 days, then starved in the laboratory for 2 mo. Dry weight gain in the racks, dry weight loss during starvation, and net dry weight gain were estimated for individuals of both groups; rate of oxygen consumption ($\dot{V}O_{2}$) was measured during the period of starvation. Heterozygosity at five polymorphic enzyme loci was measured for a subset of the sample. L individuals were significantly more heterozygous and had significantly lower weight-standardized $\dot{V}O_{2}$ ($\dot{V}O_{2_{s}}$.) than S individuals. There was a negative relationship between $\dot{V}O_{2_{s}}$ and dry weight gain in the racks for all individuals. During starvation in both groups, a positive relationship existed between $\dot{V}O_{2_{s}}$ and dry weight loss; the slopes of the S group were significantly greater than those of the L group. Lower $\dot{V}O_{2_{s}}$ is associated more w...