Influence of yolk blackish pigmentation of Siberian sturgeon on reproductive performance and larval survival

Within a cohort of farmed Siberian sturgeon (Acipenser baeri), some females produce eggs which show a blackish pigmentation of the ooplasm. An experiment was carried out to test whether this characteristic might influence the reproductive success and larval survival as compared to females having usual non-pigmental yolk. There were no differences in either the progress of germinal vesicle migration or the 50% in vitro maturation time course before hormonal injection. The latency, relative quantity of eggs, fertilization rate and embryonic survival were similar. The pigmentation of yolk significantly depressed the second part of embryogenesis. Neither the number of hatchlings, normal or abnormal, survival after weaning and the mean weight of 14 days post-hatch larvae were different. For the first time, rates of hatching for normal (70%), abnormal (11%) and non-hatched (7%) larvae, referred to the embryo survival at final stages, are reported with normal appearance eggs. © Rapid Science Ltd. 1998