THE ENERGY CONTENT AND CHEMICAL-COMPOSITION OF EGGS, MUSCLE AND LIVER IN WINTER SPAWNING VENDACE (COREGONUS-ALBULA L) BEFORE SPAWNING

Gross energy and crude fat contents of the eggs of one winter spawning vendace population were lower than those of two other populations studied. There was, however, no difference in the protein content of eggs between these populations. In a population, where the values of measured parameters of eggs were low, the fat contents of muscle and liver of female fish were, in turn, higher than in a comparative population. There was no difference in Ca or Mg contents of eggs between the two populations studied. The amount of energy of individual eggs changed noticeably (from 66 to 116.5J/egg) between the three vendace populations studied. The reason for the differences was the size difference of eggs between the populations. The gonadosomatic-index was nearly the same for all populations, but the relative fecundity changed greatly between populations.