Feeding behaviour of cod (Gadus morhua) in relation to spawning

The food consumption and egg production of 26 adult (13 female and 13 male) Atlantic cod (Gadus morhua) were monitored during prespawning, spawning an d postspawning periods. Females spawned from late January to mid-April. Fee ding activity occurred from December to early January and ceased for female s, on average, 36 days (15-54 days) before the onset of spawning. The durat ion of spawning by females was, on average, 42 days (10-61 days) and feedin g was suppressed by both sexes during the first three-quarters of each fema les spawning period. Mature females went, on average, 70 days or 19% of the year without eating. An abrupt increase in feeding activity, particularly by females, occurred during the last quarter of spawning or shortly after t he release of the last egg batch (on average, feeding started again after 9 1% of a female's eggs had been released or 82% of egg batches). Females con sumed greater quantities of food than males during both winter and postspaw ning feeding periods. During spawning, females lost, on average, 29% Of the ir body weight and males 14%. Fecundity ranged from 0.75 to 3.97 million eg gs per female. The volume of eggs produced by four individual females (rang e = 1285-5995 mi in four to 11 batches) ranged from 99 to 195% (mean 150%) of a female's postspawning body volume. Six immature cod fed throughout the experimental period and gained, on average. 8% of initial body weight. Lab oratory results were supported by stomach fullness index values of Georges Bank cod exhibiting different maturity states.