HISTOLOGICAL OBSERVATION ON THE OVARY DEVELOPMENT OF CULTIVATED ACROSSOCHEILUS FASCIATUS

Morphological and histological features of ovary development of Acrossocheilus fasciatus were studied using dissecting and tissue sectioning techniques. The results show that the ovary development in the first sexual cycle contained —Ⅳ continuous stages. Four to five months after hatching (MAH), the ovary was at stage Ⅰ and contained stage Ⅰ oocytes. Six to 18 MAH, the ovary was at stage Ⅱ, and contained stage Ⅱ oocytes, during which unilaminar follicle membrane formed. Nineteen to 20 MAH, the ovary was at stageⅢ, in which stage Ⅲ oocytes were contained, the number of layers in follicle membrane changed from one to two, the zona radiate formed between the plasma membrane and follicle membrane. Furthermore, the vacuole and yolk granule appeared in the cytoplasm. Twenty-one to 22 MAH, the ovary was at stage Ⅳ, stage Ⅳ oocytes were contained, the oocyte cytoplasm was full of yolk granule. Twenty-three to 24 MAH, the ovary was at stage Ⅴ, stage Ⅴ oocytes were contained, and the follicle membrane at this stage began to desquamate. Twenty-five MAH, the ovary was at stage Ⅵ, empty follicle and oocytes at stage Ⅱ and Ⅲ could be found. The spawning season of this species was from June to July, the ovary changed back to stage Ⅱ in September; in December it changed back to stage Ⅲ, and over all the winter the ovary remained at this stage. In April, the ovary continued to develop and entered into stage Ⅳ. According the morphological and histological characteristics of ovary development, A. fasciatus should be classified into the group of short-term batch-releasing patterned fish.