Survival rates were determined 24 h after striped bass Morone saxatilis from 9 to 78 d old (i.e., days posthatch) were abruptly transferred to water with low or high concentrations of Ca2+ and Na+. These ions are often added to water containing striped bass to increase survival after harvest. Treatment waters contained these ions at the following levels: (1) low Cat, (4 mg/L) and low Na+ (9 mg/L); (2) high Ca2+ (100 mg/ L) and low Na+; (3) low Ca2+ and high Na+ (1,780 mg/ L); or (4) high Ca2+ and high Na+. Survival was consistently high for fish of all ages in the high Cat+–high Na+ treatment. However, survival in all other treatments varied depending on fish age. Yolk-sac larvae (9 d posthatch) had high survival in water with high Na+ and had low survival in water with low Na+; survival of yolk-sac larvae was not related to Ca2+ concentration. Survival of the youngest postlarvae tested (16 d posthatch) was remarkably different from that of yolk-sac larvae; the high concentration of Ca2+ reduced mortality and the low Ca2+–high Na+ combination was acutely lethal. In both treatments with low Ca2+, there was an increase in survival with age of fish older than 16 d. Fish that were 78 d old had 100% survival in all treatments for 24 h, and after 72 h, survival was 97% or higher in all treatments.
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Grizzle et al. (1994) studied this question.