The haemoglobin polymorphism in Atlantic cod (Gadus morhua L.); genotypic differences in somatic growth and in maturing age in natural populations. In: The propagation of cod Gadus morhua L.: an international symposium, Arendal, 14 - 17 June 1983

摘要

The two common alleles at the polymorphic haemoglobinlocus HbI (Sick, 1961) in the Atlantic cod (Gadus morhuaL.) code for proteins whose functional properties aredifferentially influenced by environmental temperatures(Karpov and Novikov, 1980). In the present study HbIgenotypic mean lengths in a total of 275 immature specimens(0.5 - 1.5 year of age) from 8 samples taken in theTrondheimsfjord and Oslofjord during 1977-1981 were investigatedby rank correlation analysis. In males theoverall genotypic mean length rank was HbI^2-2 >HbI^1-2>HbI^1-1, while i n females HbI^l-2 >HbI^2-2 >HbI^1-1; bothranks were highly significant.The age at first spawning (A_m) was determined by otolith reading in a sample of 118 male cod caught duringspawning in the Trondheimsfjord in 1983. In this samplethe individual A_m ranged from 4-7 years with a significantly lower mean for the HbI^2-2 genotype. The A_m ofheterozygotes was intermediate but not significantlylower than for the HbI^1-1 genotype. Some populationgenetic and aquacultural implications of these resultsare briefly discussed.