Effects of delayed fertilization on embryo viability in walleye Sander vitreus (Mitchill): the role of maternal effects

Abstract

The effects of delayed fertilization on embryonic viability in walleye Sander vitreus were examined using laboratory fertilization and incubation trials. Both fertilization success (survival to 10 h post-fertilization) and embryonic survival (from 10 to 168 h post-fertilization) generally declined with increasing ova storage time but trends varied significantly among females. Embryonic survival of individual egg batches was positively related to fertilization success. The slope of the relationship between fertilization success and ova storage time was negatively related to maternal fork length indicating that ova quality declined more rapidly with storage time for larger females than for smaller females. In contrast, the slope of the early embryonic survival v. ova storage time relationship was not significantly related to maternal size.

Fish Oocyte Ageing and its Effect on Egg Quality

“…Oocyte ageing is accompanied by a significant increase in the ovarian fluid protein concentration (Lahnsteiner, 2000;Lahnsteiner et al, 2001;Aegerter and Jalabert, 2004;Rime et al, 2004), which can also lead to increased turbidity (Wojtczak et al, 2004;Johnston et al, 2008).…”

Quantifying quality attributes of walleye eggs prior to fertilization—Impact of time of ovulation and gametes storage

“…It was also observed in this study that freshly ovulated eggs of poor quality were not suitable for long storage. For instance, in one sample with the lowest survival rate after 8 h (17%), no viable embryos were observed after 42 h. Similarly, Johnston et al (2008) demonstrated that fertilization success in walleye eggs declined with increasing ova storage time with considerable variations among females. Fertilization success for some females was consistently over 85% through 24 h storage time, but declined with storage time (b 30%) for the eggs of other females.…”

Comparison of Walleye Egg Survival Following Fertilization at Differing Egg Depths

“…Perhaps the late spawning season caused eggs to become overripe, especially as the season progressed as it was noted in 2018 that several females had already spawned some eggs before the remaining were manually stripped. Walleye eggs are considered to take an intermediate amount of time to overripen with successful fertilization and development of eggs that were stored for 24 hours post ovulation (Johnston et al, 2008). Although slight changes in storage temperature (Rinchard et al, 2005) and individual female variation in rates of egg deterioration post ovulation can reduce fertilization success in walleye (Johnston et al, 2008).…”