施氏獭蛤(Lutraria sieboldii)性腺发育和生殖周期的研究

STUDIES ON THE SEX GONAD DEVELOPMENT AND REPRODUCTIVE CYCLE OF LUTRARIA SIEBOLDII

采用组织学方法对湛江市遂溪县草潭镇施氏獭蛤的性腺发育和繁殖规律进行了研究。结果表明,施氏獭蛤的性腺发育以1年为1个周期,可分为增殖期、生长期、成熟期、排放期和休止期。雄性生殖细胞发生经历精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子等时期,精原细胞具有A型和B型两种类型。施氏獭蛤卵子的发生可分为卵原细胞期、生长初期、生长中期、生长后期和成熟期。较晚期的卵母细胞和成熟卵子的核仁变成双质核仁。流沙港海区施氏獭蛤性腺指数峰值出现在1月,为3.47%;该贝的繁殖期为10月—次年4月,繁殖期水温为16.2—26.5℃。雌、雄性腺发育基本同步,雄性发育略快,雌雄比为2:1。

The reproductive cycle and gonadal development were studied in Lutraria sieboldii Caotan township, Suixi County, Zhanjiang City by means of histological section. The gonadal development of L. sieboldii was divided into five stages： proliferating stage; growing stage; maturing stage; spawning stage; resting stage. The spermatogenesis in L. sieboldii included five stages： spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid and spermatozoon. At the stage of spermatogonium, the spermatogonia morphologically shew different types, that was type A and type B. The oogenesis of L. sieboldii could be divided into oogonium stage, early growth stage, middle growth stage, late growth stage and mature stage. The nucleolus of late developing oocytes and ripe eggs became amphinucleous. The peak gonadal-somatic index of 3.47% was observed in January. Its breeding season was from October to next year April （16.2--26.5 ℃）. The developmental speed of male gonad was slightly greater than that of the female. The ratio of female to male was 2 ： 1.