东南太平洋智利竹鱼卵巢发育的组织学观察

根据大型拖网渔船"开欣"轮2010年9-10月以及"开富"轮2011年8月在东南太平洋海域采集的441尾智利竹鱼样本,对雌鱼卵巢进行组织学切片与观察。结果表明:(1)智利竹鱼卵母细胞发育分为5个时相,其中第2时相核膜外出现透明层,第3时相胞质中形成大量卵黄颗粒和油滴,第4时相核膜开始溶解并且能观察到精孔结构,第5时相成熟卵粒与滤泡膜分离;(2)卵径分布图显示,Ⅳ期卵巢中有各种不同卵径的卵粒,并且存在两个明显的高峰;(3)卵巢内卵母细胞发育不同步,产卵类型属于分批非同步型;(4)从8月底到10月初是智利竹鱼性腺发育高峰期。

Histological observation on the ovary development of Chilean jack mackerel (Trachurus murphyi) in the southeast Pacific Ocean

A total of 441 Chilean jack mackerel(Trachurus murphyi) were collected by two large-scale trawlers named "KAIXIN" from September to October 2010 and "KAIFU" in August 2011 in the southeast Pacific Ocean.In this paper,the histology of ovary was studied.The main results are:(1) The development of oocytes of Chilean jack mackerel was composed of five phases.In the phase 2 of oocyte development,there appeared a transparent layer in the outboard of nuclear membrane.A lot of yolk granules and lipoid vesicles formed in the cytoplasm during the phase 3 of oocyte development.Some of the nuclear membranes began to dissolve when the phase 4 came and we could find micropyle near the animal polar.The mature oocytes were apart from follicle membrane in the phase 5 of oocyte development.(2) The size distribution of eggs showed there were varied oocytes in the ovary of stage Ⅳ and there were two obvious pinnacles in the figure.(3) The spawning pattern of jack mackerel is multiple spawning that we could find more than one phase of oocytes in the same ovary at the same time.(4) The gonads were developing at a high speed from late August to early October.