STUDY OF SOME GONADIC GROWTH INDEX OF GREAT STURGEON (HUSO HUSO) CULTURED IN BRACKISH WATER CONDITION

摘要

Recognition of Gonadic feature in sturgeons is important for caviar production, early maturity and recruitment. The aim of this investigation was to examine effect of different content of food, Somatic growth and blood parameter on Gonadic growth. Four diets with constant protein (%40) and different energy content (400,425,450,475 kg/l00g) was fed to 74 Grate sturgeons (4-5 years old) cultured in brackish water pools in Bafgh-IRAN. every three month we biometry fishes, Blood sampling was performed incaudal vein and plasma was frozen until future analyses, Glucose was measured with Authoanalyser, calcium and magnesium with spectrophotometer and sodium and potassium with film photometer, Hormone profiles measured by Radio Immunoassay. Histological preparation was stained with Hematoxylin & Eosin. In male diet had not affect on gonadic growth, but in female it had significant correlation. Somatic growth only in female had direct correlation with gonadic growth and with increase total length and weight, gonadic growth was increased. Among serum biochemical parameter, with progress of gonadic growth, in male magnesium decreased and in female sodium increased. Among hormonal profile, in male just testosterone, and in female just cortisol had significant correlation and with progress of gonadic stage were increased. Progesterone and estradiol had not significant correlation that it is because for young fish. Analyses and comparative of result show that blood profile, diet content and somatic growth hadcorrelate with gonadic growth and with use of this factors, we can decrease long time of maturation in sturgeons.