EFFECTS OF PERIODIC STARVATION ON REPRODUCTIVE INVESTMENT IN 1ST-TIMESPAWNING ATLANTIC COD (GADUS-MORHUA L)

Prior to the onset of sexual maturation 1-year-old farmed Atlantic cod were either subjected to periods of short-term starvation ranging fro m 3 to 9 weeks (3 alternating periods of 3 weeks starvation separated by 1 week of feeding) in duration or were held on full rations from Ju ly to November. At spawning the fish that had been starved for 9 weeks weighed 60% of those held on full rations. The fish held on full rati ons had significantly higher fecundities than the fish that had been s tarved for 9 weeks, but these differences were related to differences in body size; relative fecundities were similar for fish in both group s. Reduced growth and liver sizes in feed-restricted groups did not re sult in lower proportions of maturing fish. Thus, the imposition of sh ort periods of starvation did not solve the problem of early maturatio n in cod culture. Throughout a combined starvation and spawning period from January until May, females lost more of initial total, somatic a nd liver weight than males. The analysis showed that, in total, female s invested more in reproduction than males.