Due to their interest as a live baitfish, production protocols for Gulf killifish, Fundulus grandis, have been evaluated and modified since the late 1970s. However, they have not been widely adopted by producers, due in part to limited understanding of commercial-scale grow-out techniques to market size (> 6 cm). Recent studies have shown that Gulf killifish can be acclimated to fresh water just seven weeks after hatching and grown out to market size in freshwater ponds. Following initial freshwater grow-out trials, it was apparent that further information was needed to guide potential inland killifish producers in making more informed decisions about stocking.
Two studies were conducted to test whether Gulf killifish cohorts can be stocked throughout the warmer months and at greater densities. In the first study, the effects of stocking time on growth rate and survival were evaluated over a 12 week period. Two juvenile cohorts, 7-9 weeks old, were stocked at 25,000 fish/ha, one month apart. While the first cohort had lower survival, both cohorts across all ponds grew rapidly, reaching market size in 22-32 days (Table 1). In the second study, density effects on growth rate and survival were evaluated over a 12 week period. Juveniles, 7-9 weeks old, were stocked at 25,000 fish/ha or 50,000 fish/ha. Survival did not differ between densities and fish at both densities grew to over 7.5 cm in length on average. While individual growth in length was lower in the higher density (Table 1), killifish at both densities reached market size in 29-31 days. To meet market demands consistently, inland producers may need to stock ponds multiple times over a growing season at a stocking density of at least 50,000 fish/ha in freshwater ponds.