Metamorphosis in summer flounder: Effects of acclimation to low and high salinities

Document Type


Date of Original Version



The aim of these studies was to provide larviculturists with information about the effect of low and high salinities on the survival, growth, and development of summer flounder (Paralichthys dentatus) with the goal of enhancing commercial success of land-based flounder culture. Larvae were transferred after first feeding and prior to the onset of metamorphosis and monitored for 3 to 7 weeks. In experiments 1 and 2, larvae were raised in 2-1 bowls containing seawater altered to salinities of 14, 30, or 38 ppt at starting densities of 3 premetamorphic and 6 prometamorphic larvae/l, respectively. Survival and development were not affected, nor was growth in experiment 1. Growth was affected in experiment 2, and larvae in 14 ppt had greater total lengths than larvae in 38 ppt. In experiments 3 and 4, larvae were raised in 38-1 tanks at starting densities 4 and 3 prometamorphic larvae/l, respectively, containing water with salinities of 8, 30, or 38 ppt or in salinities of 8 and 30 ppt. Again, survival was not significantly affected by salinity In experiment 3, 8 ppt resulted in better growth and more advanced development; however, no differences were found in experiment 4. Overall, 38 ppt may tend to result in adverse effects. Larval summer flounder are not adversely affected by low salinity (8 or 14 ppt) and were observed in some cases to grow and develop better in environments more closely approximating their internal environment.

Publication Title, e.g., Journal