THE GROWTH-PATTERN AND SEXUAL-MATURATION OF ATLANTIC HALIBUT (HIPPOGLOSSUS-HIPPOGLOSSUS L.) REARED IN LARGE TANKS FOR 3 YEARS

The weight gain of 180 tagged halibut (88 females and 92 males) was st udied in a 3-year rearing experiment conducted at 7 degrees C. Two siz e-classes of young halibut (mean weight 1.8 and 3.2 kg) were stocked a t two densities (11 and 22 kg/m(2)). The fish were fed frozen capelin and herring to satiation 6 days a week. The males became sexually matu re at an average weight of 3.2 kg and the females at an average weight of 12.7 kg. There were seasonal changes in growth associated with sex ual maturation, but, in general, the mean weight of both females and m ales increased linearly with time. Thus, the absolute growth rate did not change within the size range 2-12 kg (3.2 kg/year) and 2-7 kg (1.4 kg/year) for females and males, respectively. Therefore, it may be mo re appropriate to compare the growth rates of halibut, using absolute growth rate (kg/year) rather than specific growth rate (SGR, %/day). T he shape of the growth curve of each tagged fish was studied by regres sion analysis and the deviations from linear growth were related to th e onset of sexual maturation.