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

Flounder, Paralichthys olivaceus larvae of different ages (1, 9, 18 an d 27 days after hatching) were exposed for 120 h under food deprivatio n at various salinities (0, 4, 8, 12, 16, 20, 32, 36, 40, 44, 48 and 5 2). 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 1 6 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 decre ase rather than increase in salinity below ambient levels, and that th e salinity tolerance of the larvae varies with age and exposed time.