【作者】 何振邦；

【导师】 洪万树；

【作者基本信息】 厦门大学 ， 海洋生物学， 2008， 硕士

【摘要】 本文以中华乌塘鳢(Bostrichthys sinensis)为研究对象,在3个温度(24±0.5℃、28±0.5℃、31±0.5℃)条件下进行中华乌塘鳢受精卵培育,观察在所设定的温度条件下仔、稚鱼及幼鱼的发育状况,运用组织学方法观察了中华乌塘鳢原始生殖细胞(PGCs)的形成、迁移,性分化规律以及性比变化,探讨温度对中华乌塘鳢性分化和早期性腺发育的影响,为中华乌塘鳢的温度诱导性分化提供理论依据。实验结果显示,在28±0.5℃的培养温度下,1日龄仔鱼原始生殖细胞(PGC)位于消化道中肠靠近前肾管的腹膜上皮;5日龄仔鱼PGCs增殖且有向前肾管两侧迁移的趋势;20日龄生殖嵴及原始性腺形成;25日龄生殖嵴内产生单个PGC;50日龄卵巢腔的形成,从解剖学水平标志着卵巢开始分化;55日龄卵巢腔中初级卵母细胞的出现,从细胞学水平标志着卵巢分化的开始;95日龄精小叶的形成及输出管的出现,从组织学水平标志着精巢开始分化;120日龄初级精母细胞的出现,从细胞学水平标志着精巢分化的开始。4月龄时贮精囊出现,囊内未见精子的存在。在24±0.5℃的培养温度下,60日龄卵巢腔形成及卵原细胞出现,80日龄初级卵母细胞出现;在31±0.5℃的培养温度下,50日龄卵巢腔形成且初级卵母细胞出现。性腺分化程度与体长密切相关。对分化过程中的原始生殖细胞、卵细胞、精细胞及贮精囊的组织学特征进行观察。精巢的内部结构是小叶型,其精原细胞及精母细胞存在于精小囊中,同一个精小囊内的精细胞发育基本同步,精小叶的排列没有一定的规律。贮精囊被结缔组织隔膜分隔成许多小室腔,小室腔内有分泌物。中华乌塘鳢的卵巢腔形成方式是在性腺外侧出现组织突,组织突向上向下延伸,在侧面融合而形成卵巢腔。用较高温度(31±0.5)℃和较低温度(24±0.5)℃对受精卵及仔稚鱼连续温度处理,都能轻微提高雌性性比,但与对照组性比差异不显著。更多还原

【Abstract】 In this paper,the fertilized eggs of Chinese Black Sleeper(Bostrichthys sinensis) were incubated and larvae were cultivated at three different water temperatures (24±0.5℃、28±0.5℃、31±0.5℃).The growth of the larvae was investigated.The migration of primordial germ cells(PGCs),the gonad sex differentiation and sex ratio were investigated using histological methods.The effects of temperature on sex differentiation and growth were studied,in order to provide the scientific data for the influence of temperature on sex differentiation.The results were as follows:Under the cultivated temperature(28±0.5℃),on day 1,the PGC was at the peritoneal epithelium.On day 5,PGCs migrated towards the pronephric ducts.The genital ridge and primordial gonads were formed on day 20.On day 25,PGC was found in the genital ridge.The anatomical sign of ovarian differentiation was the formation of ovarian cavity,which appeared 50 days after hatching.The mitosis of oogonia happened on day 55.The anatomical sign of spermatic differentiation was the formation of seminiferous lobular and vas efferens,which appeared 95 days after hatching.The mitosis of spermatogonia appeared 2 months after hatching.The seminal vesicle was found 4 months after hatching.Under the lower temperature (24±0.5℃),the the formation of ovarian cavity happened on day 60.The mitosis of oogonia happened on day 80.Under the higher temperature(31±0.5℃),the formation of ovarian cavity and the mitosis of oogonia happened on day 50.The phase of early gonad sex differentiation was related to the body length.The histological characteristics of PGCs,oocyte cell,spermic cell and seminal vesicle were observed.The spermatogonium and spermatocyte were found in the seminal cysts.The structure of the testes was lobular type,but the arrangement of the seminiferous lobulus is irregular.The seminal vesicle was divided into many locule lumina by the connective tissue partition.The locule iumina were full of secretion.The tissue outgrowths on gonad elongated and then fused to form the ovarian cavity.Lower temperature and higher temperature could increase the female sex ratio slightly compared with cultivated temperature(28±0.5℃).更多还原