桃花水母及其生态学研究进展

桃花水母是一种濒临绝迹、古老而珍稀的腔肠动物，已有数亿年以上的生存历史，是地球上最低等级的无脊椎动物，是腔肠动物中生活于淡水中的仅有种类，是进化过程中的关键物种，具有极高的生态和人文价值，重要的学术价值和观赏价值。由于三峡水库的蓄水，桃花水母的生境将惨遭淹没，桃花水母濒临灭绝，这一珍贵物种的灭绝，不仅是世界物种多样性的损失，也是我国古代记载的“桃花鱼”这一文化资源的永久丧失。由于桃花水母较为罕见和出现时间极短，人们对其知之甚少，故本文从其生物学特性、出现时间、种类、分布以及研究现状等方面对桃花水母进行了较为系统的概述，提出了保护和研究桃花水母的科学意义并指出了今后研究的方向。

Advance in the study on the status and ecology of Craspedacusta

Craspedacusta is one kind of age-old, rare and precious coelenterates which is close to extinction. It is the lowest rank invertebrate on the globe whose life history has been over a few hundred million years. Not like the other coelenterates, it lives in freshwater. It is the key species in the evolution process, and of great value in ecology,human culture, learning and enjoyment. The habitat of Craspedacusta will be inundated with the three gorges reservoir's storing water. A crisis of extinction is facing Craspedacusta without its habitat. The extinction of this valuable species does not merely mean the loss of the diversity of species in the world but also means permanent loss of thc cultural resource of "oeach blossom fish" which was recorded in Chinese history. People know little of Craspedacusta because it is rare and the period of its appearance is brief.The biological characteristics, appearance time, species, distribution and status of studies on Craspedacusta were summarized systematically, and the meanings of conserving and studying craspedacusta were also revealed.