Summary: Formation and development of primary germinal tissue of cultured Acipenser sinensis were studied by light microscope. The primordial germ cell was firstly seen between the nephridium area and yolk sac of fish, 1.7cm T.L., on the third day after hatching. By the 11th day, the genital fold formed, which was composed of several cells. With the primordial gonad growing, the blood vessels appeared in it when fish was 2 months old, with a average T.L. of 7.1 cm. The adipose fatty tissue appeared by the age of 7 months, average T.L.59 cm. Histological sex differentiation of the gonads occurred at the age of 9 months, 0.6~1.1kg B.W., and the gonads entered stage 1, during which mitosis of the spermatogonia and oogonia occurred. With the primary spermatocytes or oocytes appearing, the testes or ovaries reached stage 2. The testes reached stage 2 when fish was 22~26 months old, 1.55~5.6kg B.W., and the ovaries reached stage 2 when fish was 30~36 months old, 3.1~8.2 kg B.W.. After the age of 3 years, the gonads, in succession, became what could be sexed by gross examination, and at age 5 years, 18~35.5kg B.W., all of the gonads could be sexed by gross examination and still remained in stage 2, with the oocyte diameter of 60~240μm. Besides, the results inferred that in the Yangtze River, all of the fingerlings arriving at the estuary had gonads with no anatomical sex differentiation and most of them no histological sex differentiation.


附件下載：Xihua Chen, Qiwei Wei, Deguo Yang, et al. Observations on formation and development of primary germinal tissue of cultured Chinese sturgeon. 5th International Symposium on Sturgeon. 2005, May 9-13.pdf