Salinity tolerance of the Seminole killifish, Fundulus seminolis, a candidate species for marine baitfish aquaculture

Aquaculture of marine baitfish species is still in its relative infancy and the increasing value of coastal property is forcing marine aquaculture inland. Fundulus seminolis, a freshwater killifish species endemic to Florida, has shown economic potential for use as a marine baitfish, with a small number of commercial operations currently in production. The objectives of this study were to determine both acute and gradual salinity tolerances as well as an upper lethal salinity tolerance for the species. Two separate acute acclimation experiments, natural seawater and sodium chloride, were carried out to determine if survival was influenced by the salinity source. F. seminolis were able to tolerate acute transfer to 0, 8, and 16 g/L using both salinity sources but only those in natural seawater were able to survive in 24 g/L. No survival was observed regardless of salinity source after acute transfer to 32 g/L. A gradual acclimation using natural seawater was also investigated to examine survival at various acclimation rates. A survival rate of 100% was achieved regardless of acclimation rate when salinity was changed from 0 to 32 g/L in 24, 48, 72, and 96 h treatment groups. An upper lethal salinity determination yielded an LC-50 of 60 g/L with a maximum salinity tolerance of 78 g/L. Results of these experiments provide information pertinent to the successful culture of this rarely studied species. Additionally, experimental outcomes will help to shape the marketing and distribution strategies for F. seminolis as a marine baitfish.