Egg Quality Traits and Predictors of Embryo and Fry Viability in Red Snapper Lutjanus campechanus
Coastal Sciences, Gulf Coast Research Laboratory
The quality of red snapper eggs is highly variable and unpredictable in aquaculture, leading to high mortality during early larval rearing. In this work, the viability of red snapper eggs was monitored from fertilization until unfed larvae expired because of exhaustion of vitelline reserves to determine egg quality traits in this species. The spawns were obtained via strip spawning wild-caught females following hormonal induction with chorionic gonadotropin. Females were induced immediately after capture (wild group, n = 17) or held captive for the entire maturation period prior to induction (captive group, n = 7). Candidate predictors of egg quality measured on the female parent at the time of induction or on the spawn at ovulation were evaluated using correlation and multiple regression analysis. The fertilization rate, the hatching rate, and the duration of survival of unfed larvae post hatch were weakly correlated to each other (-0.23 < r < −0.08), revealing occurrence of distinct and independent components of egg quality. Spawns from captive females were characterized by a longer latency interval between hormonal induction and ovulation, lower fecundity, and lower hatching rates, as compared to those from wild females. Among the wild brood fish, a positive correlation was observed between the age of the female and the hatching rate. The best model optimized during stepwise multiple regression analysis of hatching rate data only explained 34% of the variance for this trait and no model could be optimized for the prediction of fertilization rate or the duration of survival post hatch. These results highlight the need to develop alternative egg quality measures to predict the viability of fry with confidence.
(2017). Egg Quality Traits and Predictors of Embryo and Fry Viability in Red Snapper Lutjanus campechanus. Aquaculture Reports, 7, 48-56.
Available at: https://aquila.usm.edu/fac_pubs/15083