Patterns of Reproduction of Pontocaspian Relict Paramysis lacustris within Distribution Area

Reproduction has been studied of Paramysis lacustris, pontocaspian relict, in the centre of its natural area, and in southern and northern zones of acclimatisation. Life cycles of the animals are identical in the distribution area. The effect of female size on fecundity is only slightly expressed within each generation. Significant correlations of these indices were obtained in seasonal aspect. Specific fecundity is represented by maximum values in the centre of the area and declines in the north-western direction of introduction. The relation of fecundity to egg weight reflecting correlation of K-r reproduction strategy is reduced in the regions of introduction. Reproduction effort, i.e. ratio of eggs weight to female weight, is the most stable index within the distribution area. Cumulative potential growth, including soma as well as generative products, was nearer in spite of considerable temperature difference in animal growth.