Comparative study between juvenile and adults of yellowfin seabream Acanthopagrus latus in plasma biochemical indicators induced by different salinities

الملخص EN

Laboratorial experiments were carried out on juvenile and adults of A.

latus to estimate and compare the effect of direct transfer from the control salinity of 1.5 psu to the different salinities of 1.5, 7.5, 15, 30 and 45 psu during the periods of 6, 24, 48 and 96hrs for short term effect experiments.

Some physiological parameters (PCV, Osmotic pressure, muscles water content, total protein, glucose, sodium Na+, potassium K+ and chloride Cl-) were tested in plasma of the two age stages.

Results for all parameters showed a clear ability of adults to Osmoregulate and adapt a wide range of salinities ranged from 1.5 psu to 45 psu and explain why juvenile die at the salinity 45 psu after 48 hrs of transport by showing the insufficiency of juvenile to Osmoregulate and the high exhaustion of body activities in this salinity.

The results indicated that the salinity increase caused an increase in plasma PCV, osmotic pressure, (sodium, potassium and chloride ions), total protein and glucose.

Also, a decrease in water content of muscles of juvenile and adults.

The time of 96 hrs was not enough for juvenile to reach the stable condition at high salinities, while adults showed more constancy at the end time of experiment in all salinities.