【作者】 刘顶海；

【导师】 张继红；

【作者基本信息】 上海海洋大学 ， 水产养殖， 2011， 硕士

【摘要】 海蜇隶属腔肠动物门、钵水母纲、根口水母目、根口水母科、海蜇属,主要以浮游动物为食。海蜇发育经历多次变态过程,生活史分为有性世代和无性世代。螅状体是其无性生活史的重要阶段,受精卵发育至浮浪幼虫孵化,浮浪幼虫经变态发育为螅状体,同时螅状体生成的足囊又可以萌发形成新的螅状体[1]。横裂生殖是大多数钵水母特有的一种无性繁殖方式,螅状体经过横裂生殖产生碟状体,碟状体经过15天左右长出棒状附着器发育为幼蛰。影响海蜇幼体生长与发育的因素包括温度[2-6]、盐度[7-10]、光照[11-12]、营养[13-15]、pH[16]、溶解氧[17-18]等。2009年10月～2010年9月,在山东好当家水产研究所,实验从冬季海蜇螅状体保苗到第二年秋季海蜇收获,对海蜇四触手螅状体两种发生方式（受精卵发育和足囊萌发）,浮游幼体形态特征及生长规律,海蜇苗种培育过程中适宜的温度、盐度和密度以及海蜇池塘养殖生长规律进行了研究,以期待为海蜇早期发育生物学研究及池塘养殖提供基础参考资料。一、海蜇四触手螅状体两种发生方式通过对海蜇胚胎发育和足囊萌发进行连续观察,发现海蜇四触手螅状体存在两种形成方式:第一种方式为受精卵（水温26±1℃）经6h发育到浮浪幼虫期,浮浪幼虫25h后经过杯状体阶段,变态发育成四触手螅状体,进入附着生活阶段;第二种方式为足囊在适宜条件下萌发,首先形成杯状体,继而发育成四触手螅状体,且接近螅状体母体的足囊萌发率较高。本文观察发现的四触手螅状体形成的两种方式中,均出现杯状体的新阶段,进一步完善了海蜇的生活史过程。二、海蜇浮游幼体不同阶段的特征本章通过实验观察描述了海蜇从碟状体发育至幼蛰的形态变化,首次观察到了消化腔残留通道口的愈合过程,并重新对海蜇浮游幼体各个阶段进行了划分和定义。初生碟状体器官尚未发育成熟,浮游及捕食能力较弱,在静水中绝大多数沉于水底,主要借助水流波动推动其浮游、摄食,消化能力也较弱,从中央口到顶部是一个畅通的开放管道,消化腔残留通道口尚未封闭,在顶部中央留有一圆形洞口。当顶部形成一层薄膜,消化腔通道口封闭,初步形成伞形构造,就称为稚蜇,其浮游能力增强,在水中能自由游动,摄食量增大,消化能力提高。当伞缘逐渐下包由草帽状变为半球状,口腕愈合,口腕外端长出棒状附着器,只是性腺尚未形成,其形态特征与成体水母基本一致,此时称之为幼蛰。三、海蜇浮游幼体摄食与生长规律本章实验依据苗种培育与生产实际采样,在水温20±1℃,盐度28～29,pH7.8～8.2条件下,初生碟状体（2～3mm）经过20天的培养,棒状附着器形成,发育成为幼蜇（15～20mm）。测定分析了人工培养的初生碟状体到幼蜇的摄食量和生长规律,2～20mm的海蜇幼体伞径日生长率呈指数增长,方程为y=2.7488e0.1018x,体重与伞径的关系式为y=6×10-5-0.5x^3.5475,摄食量与伞径呈指数增长,方程为y=43.537x^1.775。四、海蜇苗种培育中适宜温度、盐度和密度的研究2010年5月5号～6月6号,根据生产车间育苗并同步取样,研究了不同温度、盐度和培育密度对海蜇幼体（碟状体、稚蜇、幼蛰）伞径平均日生长率的影响,同时与车间育苗池中幼体的生长进行对比。结果表明:（1）海蜇幼体的日生长率随温度变化而变化,温度低于24℃时,生长率随温度的升高而增大;温度高于24℃时,生长率随温度升高而减小,24℃时海蜇幼体生长最佳,日生长率为8.41%。（2）盐度低于20时,海蜇幼体生长率随盐度升高而增大;盐度高于20时,生长率随盐度升高而减小,盐度为20时日生长率最大,为9.01%。（3）在温度20±1℃、盐度28条件下,海蜇幼体生长率随养殖密度的增大,生长率递减。本实验认为海蜇幼体培育的适宜温度为21～24℃,盐度为16～20,密度为4000～8000个?L。五、海蜇池塘养殖生长规律2010年6月上旬～8月上旬,对山东荣成靖海湾海蜇池塘养殖的生长规律进行研究。结果表明,海蜇幼体放入池塘后生长迅速,从6月1号放苗到8月1号收获海蜇,伞径从2cm左右生长至30～40cm,甚至可以长至50cm。不同大小海蜇的体重与伞径呈指数增长,方程为y=0.176x^2.8914（R²=0.9907）。海蜇养殖后期,出现了饵料不足、夜光虫大量繁殖、海月水母暴发等问题,均对池塘养殖中海蜇生长造成影响。更多还原

【Abstract】 Rhopilema esculenta belong to Coelentera, scyphozoa, rhizostomeae and rhizostomatidae, and mainly feed on zooplankton. They go through several metamorphosis during its life span, which consist of an alternation between a sexual stage and an asexual stage. Scyphistoma are the important phase in the asexual life, fertilized eggs produce Planulae larvae and then develop scyphistoma, which also reproduce asexually by podocyst budding. Strobilation is a special asexual reproduction among the most scyphozoa animals, the new released ephyra could grow to juvenile jellyfish with clubbed subsidiary organ after 15 day’s culture. The factors which influence ephyra include temperature, salinity, light, nutrition, PH, DO and so on. From cultivating scyphistoma in winter in October 2009 to harvesting Rhopilema esculenta in autumn in September 2010, the two mechanisms of four tentacles scyphistoma, morphological characteristics of Rhopilema esculenta from ephyra to juvenile jellyfish, the effects of temperature, salinity and density on the average daily growth rate of juvenile jellyfish, and the growth characteristics of Rhopilema esculenta breeding in the pond were studied. Also the problems appeared in the process of breeding were discussed in Jinghai bay, Rong cheng, Shandong province.The results were as follows:1 Observation on Two Generation Modes of Four Tentacles Scyphistoma of JellyfishBy continuous observation of embryonic development and podocyst propagation?of? jellyfish,? Rhopilema esculenta,? two generation modes of scyphistoma were discovered. First, fertilized egg turned to scyphostima. This process needed about 6 h from fertilized egg to planulae, and then nearly 25 h from planulae, scyphostoma to stationary scyphistoma with four tentacles at the temperature of 26±1℃; Second, podocyst generated to scyphostima. The ratio of generation was higher with podocyst closed to scyphistoma. In this stage, podocyst first turned into scyphostoma, and then became scyphistoma with four tentacles. In this study, a new structure called scyphostoma was both found in the two scyphistoma generation modes. This discover improved the life cycle of jellyfish.2 Observation on morphological characteristic of Rhopilema esculentaThe morphological characteristics of Rhopilema esculenta from ephyra to juvenile jellyfish were depicted, and the healing process of residual access mouth of gastrovascular cavity was observed for the first time, by which the development phases of jellyfish were redefined. When residual access mouth of gastrovascular cavity was not closed, there is a circular hole in the top, the phase was defined ephyra; when the residual access mouth of gastrovascular cavity was closed, a straticulate membrane was formed, the phase was defined jellyfish larva; when the umbrella edge became hemispheric, the oral healed, and the edge of the oral grew clubbed subsidiary organ, the phase was defined young jellyfish.3 Study on feeding and growth characteristics （diameter and weight）At the temperature of 20±1℃, salinity 28～29 and PH 7.8～8.2, ephyra（2³mm）could grow to juvenile jellyfish （15²0mm） with clubbed subsidiary organ after 20 day’s culture. The food consumption and growth characteristics （diameter and weight） from newly liberated ephyra to juvenile jellyfish were analysed. It was found that the daily growth equation of juvenile jellyfish’s diameter（2～20mm）is y=2.7488e0.1018x, the relationship between weight and diameter, food consumption and diameter of juvenile jellyfish were y=6×10-5-0.5x^3.5475, y= 43.537x^1.775 respectively.4 Study on optimal temperature、salinity and density in larva breeding of Rhopilema esculentaFrom June5th to July 6th, 2010, the effects of temperature, salinity and density on the average daily growth rate of juvenile jellyfish were studied, and compared with the juveniles cultured in pond. The results showed: （1） the average daily growth rate of juvenile jellyfish varied with water temperature, it increased with the rise of temperature when temperature was below 24℃, and decreased with the rise of temperature when temperature was above 24℃. The optimal temperature for juvenile jellyfish was 24℃, and the average daily growth rate came to 8.41%. （2） The average daily growth rate increased when salinity was below 20, and decreased when salinity was above 20; the average daily growth rate came to maximum when salinity was 20, it came to 9.01%. （3） The average daily growth rate decreased with the rise of density when the temperature was 16～18℃, salinity was 28 .The study showed the optimal environment for juvenile jellyfish was temperature 21～24℃, salinity 16～20, density 4000～8000individuals ?L.5 Study on the growth characteristics of Rhopilema esculenta breeding in the pondFrom early June to August, 2010, the growth characteristics of Rhopilema esculenta breeding in the pond were studied in Rong cheng, Shandong province, and the problems appeared in the process of breeding were discussed. The experiment showed that the juveniles grew fast from June 1st to August 1st and its diameter could grow from 2cm to 30⁴0cm, even up to 50cm. The weight （wet weight） of different Rhopilema esculenta increased exponentially with the diameter, the equation was y=0.176x2.8914（R2=0.9907）.Some problems such as shortage of baits, large propagation of Noctiluca scintillans and the breakout of Aurelia aurita emerged in the later period of breeding, which influenced the growth of Rhopilema esculenta.更多还原