| Scyphistoma and ephyra of jellyfish, Rhopilema esculenta, were studied in this thesis. This thesis focuses on the effect of different environmental factors on early development stage of Rhopilema esculenta. The influence of nutrition, temperature, salinity, light, DO, poisonous metal, pH and ammonia on scyphistoma and ephyra were reviewed. A series of indoor experiments were conducted to investigate 1. effects of different conditions on podocyst generation and strobilation of scyphistoma; 2. effects of temperature on strobilation of scyphistoma; 3. effects of temperature on early development of ephyra; 4. effects of different food abundance on early development of ephyra; 5. feeding and locomotion behaviors of scyphistoma and ephyra. The primary results of these studies are listed below.1. The influence of different temperature(23℃, 16-18℃) and light level(dark and nature light level,14L:10D) on podocyst generation and strobilation of the Rhopilema esculenta scyphistoma was conducted. The result showed that appropriate nutrition and circumstance are advantageous to podocyst generation, and the number of scyphistoma which came out to strobilation increases as the experiment went on. Strobilation rate reacheed 83.33% and 87.50%; The rate of scyphistoma that forms 4-6 ephyras in group I and II both were around 50%; scyphistoma in group I that finish one strobilation need 4-6 days, and 2-4 days as to group II. The number of tentacle reborned under the last segmentation of matrix scyphistoma after strobilation was basically confirmed to 8. The scyphistoma developed evidently during the course from 8 tentacles to 16 tentacles.2. A 30-day experiment was conducted to investigate the effects of different temperature(23℃,20℃,17℃,14℃) on strobilation of scyphistoma. The results...
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