【作者】 于秀娟；

【导师】 黄长江；

【作者基本信息】 暨南大学 ， 环境科学， 2004， 硕士

【摘要】 海产腹足类性畸变现象的解剖学和组织学研究 有机锡化合物，尤其是三丁基锡(tributyltin，TBT)是一种非常有效的海洋杀生剂，但对非靶目标生物也具严重的毒害作用。其中，TBT能导致雌雄异体的腹足类雌性个体产生阴茎和输精管等雄性生殖器官，即所谓的性畸变现象(imposex)。 本文选取腹足纲(Gastropoda)前鳃亚纲(Prosobranchia)新腹足目(Neogastropoda)的骨螺科(Muricidae)、蛾螺科(Buccinidae)、芋螺科(Conidae)和中腹足目(Mesogastropoda)的宝贝科(Cypreaidae)共10个在我国东南沿海广泛分布的性畸变种，对其正常雌雄个体和性畸变个体生殖系统的形态解剖学和组织学结构进行了较为详细和系统的研究。同时，研究了有机锡污染生物指示种疣荔枝螺(Thais clavilgera)的生殖周期及其卵囊的发育过程。 结果表明，雌雄生殖系统和性畸变个体的雄性生殖器官的发育既存在着种间相似，也存在着差异。大多数性畸变个体的阴茎和输精管在形态学和组织学结构上与正常雄性的相似，但少数却有别于雄性的。性畸变个体与正常雄性个体在雄性生殖器官的发育和结构上虽有许多相似之处，但只能说明性畸变个体具有表现出雄性器官功能的潜能，却不能成为具有雄性生殖功能的个体。共有3科4种性畸变个体存在因卵囊腺破裂而导致雌性不育的现象，另有2科2种存在卵囊腺未破裂但雌性个体发生不育的现象，还发现2种性畸变个体的卵巢发育受到抑制。 疣荔枝螺雌雄性腺生殖周期的解剖学与组织学研究结果具有较好的一致性，可依据形态发育对性腺成熟度进行有效的简单判断。汕头北山湾疣荔枝螺虽然性畸变率达到100％，但种群性比并没有受到影响。由于疣荔枝螺雄性阴茎的长度随形态上的性腺成熟度的增加而增长，在选用RPSI和RPLI作为有机锡污染生物监测指标时要考虑到其阴茎长度的这种周期变化。 虽然性畸变现象引起的雌性不育可能对种群的生存造成严重威胁，但目前并无证据表明本研究的10个性畸变种已有区域性灭绝的现象。由疣荔枝螺、东风螺、棘螺三种性畸变种可构成一个比较完善的中国东南沿海有机锡污染的生物监测体系。有机锡等内分泌扰乱物质可以通过食物链传递危害人类健康，希望本文研究结果能推动中国政府更加广泛地开展对内分泌扰乱物质生态效应的调查与研究。更多还原

【Abstract】 Anatomical and histological studies on imposex of marine gastropodsOrganotin compounds, especially tributyltin (TBT), are widely used as biocidal additives in antifouling paints because of their effectiveness. However, they also cause severe damages to non-target organisms while they kill fouling organisms. For example, TBT has been reported to induce imposex in gonochoristic gastropods, that is, imposition of male sexual organs such as penis and vas deferens on female sexual organs.The present thesis evaluated 10 species of marine gastropods of families Muricidae, Buccinidae, Conidae and Cypreaidae that are widely distributed along the Southeast Coast Waters of China, and found that all of them are imposex species. The specific objectives are to describe anatomical and histological structure of male, female and imposex genital system, and to investigate annual reproduction cycle and developmental process of egg capsules in Thais clavigera, which is considered as an ideal species for biomonitoring organotin contamination along Southeast China Sea.Interspecific similarities and differences were found in the development of the genital systems of males and females and the male sex organs of imposexes. In general, morphological and histological structures of penis and vas deferens of imposexes were similar to those of normal males, but differences were also observed in a few imposexed females. Despite their similarities in the development and structure between the imposexed female and normal male, the imposex individuals may have the potential to perform the function of male sex organs, but could not function as males. In the present study, sterile imposexed females caused by the rupture of capsule gland were found in 4 species of 3 families, and sterile imposexed females without the rupture of capsule gland were found in 2 species of 2 families. In addition, the development of ovary in 2 species was restrained due to imposex.Anatomical observations were found in good agreement with histological studies on the periodic development of reproductive gonad, suggesting anatomical observation would be an effective, sufficient and simpler tool to evaluate the gonad maturity of T. clavigera. Although percentage of imposex as high as 100% in T. clavigera was found in Beishan Bay of Shantou, its sex ratio remained as normal. Because the length of penis of male T.clavigera varied with its gonad maturity, the variation of penis length along with the gonad cycle should be taken into account when the RPSI and RPLI are used as bio-indicators for organotin contamination.The reproductive failure in imposexed females may pose severe threat on the population succession of marine gastropods, however, there is no evidence existed indicating that territorial population extinction have occurred for the 10 species investigated in the present study. Instead of using T. clavigera alone, a combination of imposexed T. clavigera, Babylonia sp. and Chicoreus sp. was suggested to form a complete bio-monitoring system for organotin pollution along the Southeastern China Sea. Endocrine disrupting chemicals (EDCs) such as organotin compounds may threaten human health through the amplification of food chains, the present paper intends to provoke our government to support and fund more extensive investigations and research on the ecological effects of EDCs.更多还原