COMPARATIVE STUDY BETWEEN JUVENILE AND ADULTS OF YELLOWFIN SEABREAM Acanthopagrus latus IN PLASMA BIOCHEMICAL INDICATORS INDUCED BY DIFFERENT SALINITIES

Abstract

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.

Direct transfer to different salinities and its effect on energy and metabolic enzymes in juveniles and adults of yellowfin sea bream Acanthopagrus arabicus

“…This may also explain why the larvae and juveniles migrate to the river after adult spawning in the sea because they do not have this enzyme in an adequate level. This study confirms the results obtained in our previous study about measuring some physiological factors [osmotic pressure, PCV (Pacced Cell Voume), water content of muscles, glucose, total protein, chloride (Cl − ), sodium (Na + ) and potassium (K + )] in plasma of juveniles and adults of A. arabicus , which indicated the strong capability of adults to osmoregulate and acclimate an extensive range of salinities from 1.5 to 45 psu, and the high fatigue of body activities in juveniles in the salt concentration of 45 psu (Alkatrani, 2017). Many studies agree with the results of the CK activity in the present study.…”