Studies On Ovary Development And Sexual Steroid Change Of Varicorhinus Macrolepis In Annual Cycle

Abstract: Anatomy, histology, histochemistry, and the electron microscope observation of the matural oocytes of Varicorhinus macrolepis were studied, as well as the changes of sexual steroid in annual reproductive cycle. EXP.1:Ovary histology of Varicorhinus macrolepis was studied. The results showed as follows: Oocytes were divided into 6 phases in ovary development, and Different annual period of ovary was classified based on different phase oocytes existed different proportion in ovary(the ovary was corresponding period of the phase oocyte which the 50% that should exceed the section of field of vision appearance), Ovary of Varicorhinus macrolepis was classified into 5 stages in annual reproductive cycle, which was as follows: (Ⅰ) February - April, it was Ⅳ period. (Ⅱ) April - June : it was Ⅴ period, but it would change with different temperature. (Ⅲ) June -July: entering Ⅵ period after ovlation finishing. (Ⅳ) August: it was Ⅱ period, then resumed promptly into stage Ⅲ, storing energy in order to live through the winter. (Ⅴ) September-January of next year, ovary was in Ⅲ period and spent cold weather in winter. EXP.2 : changes of Gly, DNA ,AKP and ACP in different phase oocytes were studied by histochemistry. Changes of Gly were as follows: membrane was positive to PAS in every Phase.Ⅲ and Ⅳ Phase, The material around nucleus in cytoplasm and in liquid bubble were positive to PAS,as well as granules among liquid bubbles, While other part was negative.The results of DNA showed that there were negative except membrane to Feulgen- Rossenbeek reaction in every phase oocytes. The amount of AKP changed that it was positive of the epithelium cell in each phase oocyte, while other part was negative. ACP changed that there were shallow black, black and deep black granules in oocyte cell gap, and the granules form of gathering among the oocytes in different stages ovaries. EXP 3: Changes of Sexual steroid (E2 and 17α,20β-DHP) of Varicorhinus macrolepis were studied in annual reproductive cycle. The result showed:E2 went up to peak in March before ovulating (53.6 pg/ml around),and began to drop to minimum point from April to September and maintained at low level to January then began to rise to March. 17α,20β-DHP rose to the highest point in April , and maintained at high level to the end of ovulating. Then it decreased from July to November and maintained at low level to March of next year. EXP 4: The electron microscope observation of the matural oocytes of Varicorhinus macrolepis was studied.The results showed that the size of oocyte had nothing with the individual of the fish, and was concerning with the growth way of oocyte of the fish; There were basically complete organelle structure in matural oocyte.