محمود نفیسی بهابادی

The aim of this study was to investigate hematological factors of Asian Sea bass kidney (Lates calcarifer) in response to water salinity. For this purpose, juvenile fish with an average weight of 34.36±0.41 g were evaluated for 30 days. After 14 days of adaptation, the experiment carried out with 4 treatments and 3 replicates including 15, 35 and 50 gram per liter and fresh water. 15 fish were randomly distributed in each of the 12 fiberglass 300-liter cylindrical tanks. Fish were fed with feed pellets two times daily. Water salinity was reduced up to 3 ppt daily. At the end of experiment, blood samples were taken from caudal fish for evaluating hematological parameters and liver enzymes and kidney tissue samples was collected. The present results showed that different levels of salinity had no effect on hematological factors including hemoglobin, hematocrit and white and red blood cells count (P> 0/05). At the end of experiment, some blood liver enzymes including alkaline phosphatase (ALP) and aspartate aminotransferase (GOT) did not influence different salinity levels (P> 0/05). However, a significant difference in alanine aminotransferase (GPT) value observed between 15 and 50 ppt treatments (P< 0/05). The pathological studies on kidney tissue in all treatment (except 50 ppt) showed some changes including hypertrophy and urina tract epithelial tubule, reducing the lumen and the concentration Melanomacrophage, leukocyte infiltration and necrotic cells. Overall, at the present study sea bass fish showed a good compatibility in response to different salinity levels after 30 days. The obtained results indicated that this species could tolerate salinity changes up to brackish water and high salinity water.