The changes of serum biochemical components during carp pituitary extract and HCG induced maturation of the female Japanese eel (Anguilla japonica)

Abstract

Based on the gonadosomatic indexes (GSI) of different developmental ovary stages of the fe-male Japanese eel during carp pituitary extract and HCG induced maturation, the paper measured and analyzed six biochemical components of the serum, namely total protein (TP), triglycerides (TG), total cholesterol (TC), blood glucose (Glu), calcium (Ca) and phosphorus(P) by medical inspection methods. The results showed that the gonad of treatment group got matured gradually during 84 days with GSI in-creasing significantly to 46.32%±1.75% at the 12th injection; while GSI of the control group stayed at 2.45% ± 0.30%. There was no difference between the TP level of treatment group and control group (P 0.05) which remained relatively stable. However, the blood lipid displayed significant difference (P 0.05) until 56th day: TG and TC of the treatment group maintained a high level, averaged at (12.67 ± 2.83) mmol/L and (15.54 ± 3.01) mmol/L respectively; while control group kept a low level, averaged at (6.33 ± 4.14) mmol/L and (8.53 ± 3.30) mmol/L respectively. The Glu level of both groups carried on rising from a low level at the beginning. Correlation analysis indicated that there was significant negative correlations between TG and GSI in treatment group (r =?0.732, n=6, P 0.01). Significant correlations were found between Ca and GSI (r =0.961, n=6, P 0.01), P and GSI (r =0.775, n=6, P 0.01)in treatment group: as the growth rates of GSI, and the level of Ca and P increased dramatically from 28th day, while the control group stayed at a low level. It turned out that there is a close relationship between ovary development and lipid metabolism, and some inorganic ions (Ca, P) have played an important role in this process. Accord-ing to the nutrition requirement and metabolic rule of the female Japanese eel, it’s a new potential way to judge ovary developmental stages by measuring and analyzing the level of blood lipid or serum Ca and P.