The influence of egg size and thermal conditions of incubation on the body length and the yolk sac volume of vendace (Coregonus albula L.) eleutheroembryos

Abstract
Eggs of C. albula were incubated at 1.5 ° and acclimated for different times to 10 °. This procedure caused a varying delay in their hatching. The percentage of normal hatch and the eleutheroembryos' body length and yolk sac dimensions (height and length) were measured, and the yolk sac volume was calculated. The number of days of hatching delay was positively correlated with the total length of embryos and inversely correlated with their yolk sac volume.Dimensions of vendace embryos emerging from eggs of different size were compared. Larger eggs produced longer embryos equipped with larger yolk sacs, and differences in the yolk sac volume were far more pronounced than differences in the body length.