Giant sea perch Lates calcarifer juveniles were exposed to nominal un-ionized ammonia at 0.02 (control), 0.35, 0.62, 1.15, 1.51, 1.74, 2.04, 2.24 and 3.01 mg/l (nominal concentration) and nitrite levels of 0.04 (control), 30.56, 52.34, 101.41, 146.05 and 202.94 mg/l, in running seawater at 25-27℃, pH 7.8-8.3, 32-34 ppt salinity. Hematocrit, hemoglobin and serum glucose were measured after 24, 48, 72 and 96-h of exposure.
No significant difference in hematocrit and hemoglobin was observed in the control fish and the fish exposed to un-ionized ammonia for 24 to 96-h. Serum glucose decreased with increasing un-ionized ammonia. No significant difference in hematocrit was observed among the fish exposed to different nitrite for 24 to 96-h. Hemoglobin increased, but serum glucose decreased, with increasing ambient nitrite.
key words：Lates calcaifer, Un-ionized ammonia-N, Nitrite-N, Hematocrit, Hemoglobin, Serum glucose