Effect of post-ovulatory oocyte ageing on egg developmental success Developmental success was estimated using the percentage of alevins reaching yolk-sac resorption without exhibiting any obvious morphological abnormality (LNER, Living and Normal Embryo Rate). Bars represent the means ± standard deviations. On each graph, bars sharing the same letter are not significantly different at p < 0.05. Experiment 1 was performed using 17 females (A) and experiment 2 using 22 females (B). Post-ovulatory ageing times are indicated for both experiments.