| 摘要: |
| 针对每年春季在大型水母资源量初期调查工作中沙蜇与海蜇晚期碟状体（1～2 cm）阶段较难区分的现象，通过实验室培养观察，首次对沙蜇和海蛰晚期碟状体的形态特征进行了详细比较，总结了二者的主要差异：沙蜇的生殖腺下腔较饱满，腔内空间较大，而海蜇的腔内空间较小，每个腔内外两侧边缘弧度相近，腔与腔之间的距离较大。沙蜇的胃腔内垂直排列着两列胃丝，长胃丝分别由4个生殖腺下腔内向胃腔壁下方的中央口延伸，而海蜇的胃丝分别分布在4个生殖腺下腔内，胃腔内壁上没有或仅有少量的胃丝。当处于紧缩状态时，沙蜇的口腕呈倒圆锥形，小触指分布错综复杂，而海蜇的口腕呈圆柱形，小触指有序地收缩在口腕柱内。 |
| 关键词: 沙蜇 海蜇 晚期碟状体 形态比较 |
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| 基金项目:辽宁省自然科学基金项目(20052150)和日本学术振兴会访问学者基金项目（JSPS S 05251）共同资助 |
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| Morphological studies on advanced metephyrae of Nemopilema nomurai and Rhopilema esculentum |
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| Abstract: |
| Advanced metephyrae is one of the growth stages in the life cycles of Nemopilema nomurai and Rhopilema esculentum. In order to distinguish the advanced metephyrae (1～2cm) of N.nomurai and R.esculentum in early resources survey of giant jellyfish in every spring，The morphology of advanced metephyrae of N. nomurai and R.esculentum were studied.Their characteristics were compared and their main differentiae were summarized through laboratory cultivation and observation.The studies showed that the subgenital pits of N.nomurai are fuller and bigger than that of R.esculentum.For R.esculentum,the inside and outside radians of every subgenital pit are closer and the distance between two subgenital pits is greater.Two vertical lines of gastric cirrum are in the stomachic cavity of N.nomurai,with the longer one extending from subgenital pit to the central mouth.By comparison,the gastric cirrum of R.esculentum are distributed in four subgenital pits,and almost none of gastric cirrum is found in the stomachic cavity.When it is in the state of being contracted,the shape of central mouth of N.nomurai is crossed with smaller opening,and the cirrum are distributed anfractuously in the turbination-shaped oral canalis carpi. By comparison, the shape of central mouth of R.esculentum is eight-square,when it is in the state of being contracted, and the cirrum are distributed orderly in the column-shaped oral canalis carpi.The purpose of this study is to offer taxology evidence for investigating advanced metephyrae in natural field and forecasting of jellyfish blooming earlier, therefore to prevent jellyfish disasters. |
| Key words: Nemopilema nomurai Rhopilema esculentum Advanced metephyrae Morphological comparison |
