瓯江光唇鱼的卵巢和卵母细胞发育研究

Study on the development of the ovary and oocyte in Acrossocheilus fasciatus from Oujiang River

摘要:

采用常规生物学调查方法和组织切片技术，对瓯江光唇鱼(Acrossocheilus fasciatus)各期卵巢和卵母细胞的组织学结构特征及繁殖期进行了系统的研究。结果表明：瓯江光唇鱼卵母细胞发育可分为5个时相，其卵巢发育可分为6个时期。Ⅰ期卵巢透明，呈细线状；Ⅱ期卵巢以第Ⅱ时相卵母细胞为主；Ⅲ期卵巢以第Ⅲ时相卵母细胞为主，只有少量第Ⅰ和Ⅱ时相卵母细胞，此期伴有液泡和卵黄颗粒的出现；Ⅳ期卵巢呈长囊状，卵巢中卵粒清晰可见，以第Ⅳ时相卵母细胞为主，此期卵黄颗粒增多，核移位；V期卵巢为成熟期的卵巢，卵细胞游离。Ⅵ期卵巢处于衰退期，此时卵巢松弛，体积缩小。瓯江光唇鱼的繁殖期为每年5-8月。进入繁殖期的5-6月的卵巢以Ⅳ期为主，7-8月的卵巢有Ⅲ或者Ⅴ期卵巢。在繁殖期内5-8月平均成熟系数分别为2.75％、8.54％、3.25％和1.44％。瓯江光唇鱼的产卵类型属于连续产卵类型，在同一繁殖期内可以反复产卵数次。

Abstract:

The histological features of the ovary and oocyte and breeding season of Acrossocheilus fasciatus of the Oujiang River were studied by biologic investigation and lightmicroscope. The results showed that the change of the oocytes of the female could be divided into five phases and the development of ovary could be devided into six stages, according to the morphological and histological features. In the ovaries at stage Ⅰ, the ovaries were transparent and linear structures. In the ovaries at stage Ⅱ,the oocytes were mostly at phase Ⅱ. In the ovaries at stage Ⅲ, the oocytes were mostly at phase Ⅲ, follicular membrane and yolk grain appeared in the cytoplast. There were few oocytes at phaseⅠand Ⅱin the ovaries at stage Ⅲ. In the ovaries at stage Ⅳ, the oocytes were mostly at phase Ⅳ. The nucleus was in excursion. The number of yolk grain increased. The ovaries were a cystoid structure. The oocytes appeared obviously by nude eyes. The ovaries at stage V were mature and the oocytes were dissociating. The ovaries at stage Ⅵ were in a recession, the ovaries were in relaxation and smaller in size. The breeding season of Acrossocheilus fasciatus of the Oujiang River was from May to August. The ovaries in reproductive season were mostly in stage Ⅳ from May to June. From July and August the ovaries were in stage Ⅲ or Ⅴ. The corresponding gonadosomatic index(GSI) of ovaries from May to August were 2.75％, 8.54％, 3.25％ and 1.44％ respectively. The results of this paper indicated that Acrossocheilus fasciatus of the Oujiang River belonged to consecutive spawning type. It can spawn many times during reproduction season.