Seasonal Variation in Weight-Specific Growth Rates, Feeding Rates, and Growth Efficiencies in Microgadus tomcod

Abstract

Among Microgadus tomcod from Cumberland Basin, Bay of Fundy, exponents of the weight–length relationship (liver, gonads removed) ranged from 2.74 in April, after spawning, to 3.47 in September, after summer feeding. This implies that growth rate per unit of weight is seasonally higher in larger fish, although this diminishes on an annual basis after 2 yr in these short-lived (< 4 yr) fish. In feeding experiments larger fish after spawning increased feeding (weight-specific ration declined with weight in September, not in April-May) and grew faster, using proportionately more food for growth (growth efficiency not correlated with weight in September, positively so in April–May).