SALINITY TOLERANCE OF THE FLOUNDER, PARALICHTHYS-OLIVACEUS LARVAE WITH GROWTH

Flounder, Paralichthys olivaceus larvae of different ages (1, 9, 18 and 27 days after hatching) were exposed for 120 h under food deprivation at various salinities (0, 4, 8, 12, 16, 20, 32, 36, 40, 44, 48 and 52). Mortalities were recordid every 24 h. Salinity levels at which 50% larvae survived over the entire test period (120 h) were 16-36 for 1-day-old larvae, 16 and 20 for 9-day-old, 8-32 for 18-day-old and 8-20 for 27-day-old larvae. The greatest overall survival was recorded at 16 for 1 and 9-day-old larvae and 12 for 18 and 27-day-old larvae. The results suggest that flounder larvae can better withstand abrupt decrease rather than increase in salinity below ambient levels, and that the salinity tolerance of the larvae varies with age and exposed time.