Author:
Layla M. A.A. AlKatrani Layla M. A.A. AlKatrani
Abstract
The effects of Sudden and Gradual salinities stress on AST and ALT enzyme activity in
Oreochromis aureus fingerlings were investigated in two separate experiments in this study. The
fingerlings were suddenly transferred to five different set of salinities (5, 15, 25, 35, 45 psu) and
gradually each one hour to seven set of salinities (5, 10, 15, 20, 25, 30, 35) psu in two replicate
for each salinity for 72 hrs. Fish were killed after that and blood were taken from heart and putted
in test tubes for serum separation and serum kept in freeze until doing measurements of AST and
ALT enzymes. Results showed that all fishes were died in the salinity concentration 45 psu after
20 hrs of sudden transfer, while a 100% survival rate was recorded in other salinity
concentrations. The salinity 45 psu was considered to be out of the O. aureus tolerance range.
Findings showed a close correlation of AST and ALT concentrations with salinity increase in
sudden and gradual transfer experiments as a result of the stress which occurred during fish
acclimation to reach the homeostasis. The remarkable increase in serum ALT and AST of fish
groups exposed to sudden transfer compared with gradual transfer groups reflect the better ability
of these fishes to adapt in salinity changes of gradual transfer..
Publisher
King Abdulaziz University Scientific Publishing Centre
Subject
Water Science and Technology,Aquatic Science,Environmental Chemistry,Oceanography