【作者】 马得友；

【导师】 尤锋；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋生物学， 2010， 硕士

【摘要】 本文利用组织学方法研究了室内培育条件下青岛文昌鱼的性腺周年发育规律,与同期野生文昌鱼的性腺发育相对比,初步研究了室内青岛文昌鱼群体性别比例的周年变化,并和野生群体相比较。同时,还以本实验室诱导1个牙鲆异质群体、1个异质家系和1个同质群体的生长情况进行了周年跟踪观察,并在解剖学和组织学水平上分析了异质雌核发育牙鲆性腺的发育情况。健康的、性腺发育良好的文昌鱼采自于青岛沙子口海区,在室内进行周年培育。每月采集样品,经测量、固定以及组织切片观察,研究了其周年卵巢和精巢的发育规律。结果表明,室内培育的文昌鱼成体一周年内全长没有明显变化,仅体重在繁殖期即其性腺发育至V期时有明显增大(P<0.05),精卵排空后则恢复原来体重。文昌鱼一年内在夏季6-7月繁殖一次,能自行排放卵和精子,排空后个体的卵巢或精巢处于排放后期,然后经历I、II、III、IV和V期的发育过程,进行下一轮的性腺发育。文昌鱼精巢在IV期前先于卵巢发育,两者在IV期前发育都不同步,精巢处于IV期时间较长,一般从3月持续到5月,而卵巢处于IV期一般是在4月至5月。同时,与11月、1月、3月和6月采集的同期野生文昌鱼的性腺进行了比较,发现室内培育的文昌鱼与同期野生文昌鱼的发育情况基本一致。进一步经解剖镜和组织切片观察统计,周年室内培育的文昌鱼中有64尾雌性个体,58尾雄性个体,雌:雄为1:0.91。但对2008年11月、2009年6月和2010年3月采集的野生文昌鱼统计结果显示,雌性个体为21尾,雄性个体有15尾,雌:雄为1:0.71,上述结果特别是后者与报道的其他文昌鱼种群有一定差异,有关青岛文昌鱼性比组成还需积累更多的数据予以进一步分析。通过对2007~2008年诱导的异质、同质雌核发育牙鲆群体和家系生长发育的跟踪观察比较,发现在孵化后35-52天之间,异质和同质雌核发育牙鲆仔鱼出现死亡高峰;在17月龄时,同质雌核发育牙鲆群体个体间的全长和体重差异显著在同样培育条件下,在27月龄(510日龄)时同质雌核发育群体内,个体之间的生长也有明显的差异(P<0.05)。同时,解剖观察了23尾二龄异质雌核发育牙鲆,发现卵巢与普通雌牙鲆没有差异的有9尾,正常比例为39.13%。其余14尾则显示出卵巢发育异常现象,可以分为两种类型,一是性腺两侧发育不对称型(分为只有一侧有性腺和一侧发育迟缓两种情况),占39.13%;二是性腺两侧发育迟缓型,占21.74%。进一步对其进行了组织学和芳香化酶免疫定位研究,发现雌核发育牙鲆除了个别发育极其迟缓,大多数个体的卵巢与普通牙鲆的卵巢在细胞水平上没有明显差异,雌核发育牙鲆是否能正常产卵,还有待进一步的观察。更多还原

【Abstract】 Annual gonad development of the laboratory-reared amphioxus(Branchiost- oma japonius) was observed using histological method, and compared with the gonad development of wild amphioxus in the corresponding period of time. Then their sex ratios were preliminary investigated in both laboratory-reared and wild stocks. In the meanwile, the growth conditions of induced olive flounder(Paralic- hthys olivaceus)gynogenentic stocks including a meiogynogentic stock, a meiogy- nogentic family and a mitogynogenetic stock were tracked. The gonad developm- ent of the meio gynogenetic individuals of 2 year old was also anatomically and histologically studied.Healthy amphioxus with developed gonads were selected from Shazikou natural sea area of Qingdao in June 2008, and cultivated in our laboratory at the Institute of Oceanology, Chinese Academy of Sciences for more than one year. The samples were collected and measured, and then fixed monthly. Histological structure of amphioxus gonads was observed under light microscope. The results showed that, from Sep. 2008 to Aug. 2009, there were nearly no changes in total length of amphioxus under indoor condition. And their body weight were also no changes during this period except the reproduction period. There were significant increases of amphioxus body weight in the V phase of ovaries or testis(P<0.05), and their body weight would dropped to the former weight after reproduction. Amphioxus could breed only one time each year and the breeding period is from June to July in summer. The laboratory-reared amphioxus could release eggs and sperm spontaneously. Then their ovaries and testes were in the emission later stage, and went through I, II, III, IV and V phases in the next round of gonadal development. It was also found that ovary development did not accord with testis development until the IV phase, and testis usually developed earlier than ovary. In addition, amphioxus testis stayed in the IV phase for a longer time (from March to May) compared with ovary (from April to May). In order to compare with the gonadal development condition of wild amphioxus, samples at the corresponding time period from Shazikou were caught, fixed and analyzed in November, January, March, and June The results showed the gonad development of laboratory amphioxus was basiclly consistent with that of the wild ones. According to the statistical analysis, the annually laboratory-reared amphioxus had 64 females and 58 males, and ratio of female and male was 1:0.91. But the analysis results from the wild amphioxus collected and fixed in November 2008, June 2009 and March 2010 showed that there were 21 females and 15males, and ratio of female and male was 1:0.71. The above sex ratios, expecially the latter, were very different from the results of reported other amphioxus population structures. Then, the sex ratio in Qingdao amphioxus is needed to observe more data for the further study.According to tracking observation of induced meiogynogenetic and mitog- ynogenetic olive flounder, there was peak mortality between 35-52 days after hatching; there were also significant differences in both total length and body weights among individuals of mitogynogenetic stock in17 months age(P<0.05). Furthermore, the ovaries of 23 2-year old meiogynogenetic flounders were anatomically observed. The results showed that there were 9 individuals (9/23, 39.13%) with normal ovaries, and the remaining 14 individuals have abnormal ovaries. The malformation phenomena of ovary could be divided into two types. Both sides of ovary are asymmetric, with only one side or one side of the growth retardation(9/23, 39.13%), and the other type is that both sides of ovary were in growth retardation compared with control flounder ovary(5/23, 21.74%). By the histological observation and aromatase immunohistochemical location, the ovaries of 2-year old meiogynogenetic individuals were not significantly different from those of control female except the slower development. Whether induced gynogentic flounders could spawn or not is still required for further observation.更多还原