安朵仙水母生活史的实验观察

Laboratory observations on the life-cycle of upside down jellyfish Cassiopeia andromeda

中文关键词: 安朵仙水母  螅状体  横裂  共生藻  浮浪幼虫  胞芽

英文关键词: Cassiopeia andromeda  Scyphistoma  Strobilation  Zooxanthellae  Planulae  Bud

中文摘要:

      安朵仙水母在固着的无性繁殖螅状体和浮游的有性繁殖水母体间交替，其生活史中绝大多数环节并不是自发进行的，而是受特定的物理、化学或生物因素的影响。静止水流和雌雄个体间的交互作用对于产卵和受精是非常重要的，受精卵在64h内可经浮浪幼虫阶段变态为4触手螅状体。螅状体能通过单碟型横裂产生水母体，但对温度和光照要求严格。出芽生殖是螅状体无性繁殖的唯一方式，出芽率与温度关系最为密切。大多数碟状体在横裂的过程中生长出口腕，并在脱离螅状体12~24 h内翻转为口腕向上、外伞向下的倒立形态。水母体可通过食物和体内的共生藻获得能量。人工条件下，螅状体可长期保存，水母体可以饲养两年以上。

英文摘要:

      The life-cycle of the scyphozoan Cassiopeia andromeda was described. The tropical jellyfish alternates between a sessile, asexually propagating polyp form and a typically pelagic, sexually reproducing medusa. Major events in the metagenesis are not autonomous, but depend on the presence of and interaction with special physical, chemical or biological factors. The still water and interaction between mature individuals are important for spawning and fertilization. Scyphistoma is produced by metamorphism from oosperm and planulae. Medusa comes into being within a permissive temperature and light by monodisk strobilation. Budding increases the number of scyphistoma when the temperature is above 20 ℃. Four arms have shaped in the course of strobilation. And the young jellyfish can stand upside down in 12~24 h. Zooxanthellae supplies much energy for scyphistoma and medusa besides feed such as Artemia. In our laboratory, scyphistoma has been kept for a long time and medusa may live for over 2 years.