人工养殖条件下香螺生殖系统组织学观察及生殖细胞特征

Histological observation of reproductive system and reproductive cell characteristics of limpet(Neptunea cumingii)under artificial culture conditions

为探明香螺(Neptunea cumingii)雌、雄生殖系统发育规律及特征,以中国山东省烟台市四十里湾海域人工养殖的香螺(体质量为58.09 g±10.70 g)为研究对象,利用组织切片技术对其性腺发育及生殖细胞发生进行连续观察,并研究了水温对性腺发育的影响。结果表明:香螺为雌、雄异体,本次采样性别比为2.45∶1,偏离期望值;雄性生殖系统由交接口、交接器、贮精囊、输精管和精巢5部分组成,精子在精巢的精小叶内形成,雌性生殖系统由产卵器、囊腺体、受精囊、输卵管和卵巢5部分组成,卵细胞在卵巢滤泡中发生;雌、雄性腺发育均分为增殖期、生长期、成熟与排放期和退化期4个阶段;精子发生经过精原细胞、初级精母细胞、次级精母细胞、精细胞和精子5个阶段,卵子发生经过卵原细胞、小生长期卵母细胞、大生长期卵母细胞和成熟卵子4个阶段;在同一个体中,香螺雄性不同生殖细胞具有分批成熟、排放的特点,但雌性生殖细胞成熟、排放较为同步。研究表明,香螺雌、雄性腺均在水温较低的时期进入快速发育阶段,雄性较雌性早成熟1~4个月,在人工养殖条件下同性个体间性腺发育阶段较为接近,产卵期集中在5—6月份,具备人工规模化苗种繁育的条件。

To explore developmental characteristics of the female and male reproductive systems of limpet(Neptune cumingii),the gonadal and germ cell development was continuously observed in limpet with body weight of(58.09 g±10.70 g)cultured in Sishili gulf,Yantai,by histological technique,and the relationship between gonadal development and environmental conditions was analyzed in combination with the local water temperature.The results showed that the limpet was gonochorism,with ratio of female and male of 2.45∶1 in the samples,which deviated from the expected value.The male reproductive system was mainly composed of mating port,petasma,vas deferens,seminal receptacle and testis.The seminiferous lobulis were the tissues for spermatogenesis in the testis.The female reproductive system was primarily composed of the ovipositor,glandular vesicles as the tissue for oogenesis seminal vesicles,fallopian tubes,and ovaries.The development of both testis and ovary was divided into four stages:multiplication,growth,maturity and releasing,and degradation.The spermatogenesis was divided into 5 stages:spermatogonium,primary spermatocyte,secondary spermatocyte,spermatid and mature sperms.The oogenesis was divided into 4 stages:oogonium,small growing oocyte,large growing oocyte and mature oocyte.In the same individual,the maturation and releasing of different male reproductive cells were in batches,while the maturation and emission of different female reproductive cells were synchronous.It was found that both female and male gonads developed rapidly in the period of lower water temperature,and male matured 1 to 4 months earlier than females did.The development stages of gonads among different individuals are relatively close under the artificial culture conditions,and the spawning period was concentrated from May to June,which provides conditions for large scale artificial breeding of N.cumingii.