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以日本白令海引进的咖啡金黄水母为亲本,通过人工繁殖的方法获得受精卵.在实验室培育条件下,对浮浪幼虫、螅状体、碟状体和水母幼体等多次变态发育过程进行了系统观察,描述了各发育阶段形态变化,首次报告了咖啡金黄水母的生活史.咖啡金黄水母为体外受精,卵为沉性,受精后6h内发育为浮浪幼虫,浮浪幼虫有明显的趋光性,在54 h内变态附着为4触手螅状体.螅状体能通过多种方式进行无性繁殖,于20℃横裂生殖,每个螅状体每次横裂产生8～21个碟状体,碟状体的数量和质量与横裂前螅状体的状态有关.合适的水流和充足的食物保证了碟状体在60 d内变态为伞径10cm的育成体.人工条件下,螅状体可长期保存,水母体能饲养8～10个月. 相似文献
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《水产科学》2019,(6)
近年来灾害性海月水母种群数量在东亚海域内大幅度增加,对渔业资源及海洋生态系统造成严重灾害。横裂生殖可以使海月水母螅状体释放小水母(碟状幼体),而这一过程会扩增成体水母的种群数量。为探明温度对海月水母横裂生殖的影响,将源自日本濑户内海的海月水母螅状体由25℃分别转移至9、12、14、16、18℃5个较低的温度下,并在饥饿和黑暗状态下监测90 d。试验结果显示,横裂开始时间(或预横裂时间)、横裂率和横裂持续时间均受温度影响,平均预横裂时间在12、14℃下最短,横裂率在9、12℃下最高(约65%),横裂持续时间在较高的温度下比较短。每只螅状体所释放的平均碟状幼体数量在各温度下差异显著,14℃时最高。通过本试验验证,海月水母最适的横裂生殖温度为12～14℃,在此温度范围内海月水母横裂生殖开始的最快,并且发生横裂生殖的螅状体比例更大。据研究结果推断,暖冬可能会导致日本濑户内海下一年度海月水母的种群数量大幅度增加。 相似文献
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为研究海蜇(Rhopilema esculenta Kishinouye)同一螅状体后代的生物学特征,将由海蜇单个螅状体通过无性繁殖所产生的同母本水母体分组进行室内水泥池人工培育,观察同母本及不同母本水母体的性别分化及生长速度、体色变化、健康状况等。通过3个多月的室内养殖,6个试验组中,有4组水母体生长良好,秋季达到了性成熟。在显微镜下观察其性腺以辨别雌雄,对同母本的水母体进行了性别分析。结果表明:在人工养殖条件下,海蜇单个螅状体产生的一组后代,其个体间的生长状况存在明显差异,但体色基本相同,性别完全一致,即同母本水母体之间没有出现性别分化；而不同螅状体产生的水母体之间则存在性别差异。 相似文献
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无性繁殖是水母螅状体有效补充种群数量及扩展栖息地的重要方式,为正确掌握海月水母的无性繁殖方式进而深入了解其生活史,在显微镜下常年观察并详细描述了海月水母螅状体进行匍匐茎生殖、芽体生殖、足囊生殖、繁殖体生殖、纵向分裂生殖和破裂生殖等复杂无性繁殖方式的过程,发现繁殖体生殖可产生浮游态繁殖体芽,在水中漂浮并生长发育成螅状体,新发现一种破裂生殖方式,仅发生在螅状体极度饱食的状态下。对6种无性繁殖方式的行为特征和功能作用进行了对比分析,认为匍匐茎生殖和破裂生殖有利于螅状体种群快速增加个体数量,芽体生殖和纵向分裂生殖有利于子代幼体生长,足囊生殖有利于种群抵御不良的环境条件,繁殖体生殖有利于种群随水流进行长距离迁移,以扩展或转移栖息地。研究表明,不同的繁殖方式是海月水母应对不同环境条件的适应性繁殖对策。 相似文献
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不同环境对海蜇螅状幼体足囊繁殖和横裂生殖影响的研究 总被引：1，自引：0，他引：1
研究了不同温度，光照条件对海蜇螅状体生长及足囊繁殖和横裂生殖的影响。结果表明，适宜的营养和环境条件有利于海蜇螅状体足囊繁殖，2组实验中螅状幼体出现横裂的个数均随实验天数的增加有增长趋势。2组实验最后的横裂率分别达到83.33％和87．50％；形成4-6个碟状体的螅状幼体在Ⅰ、Ⅱ组中所占比例均在50％左右；Ⅰ组横裂过程经历时间集中在4—6天，Ⅱ组横裂过程经历时间多为2～4天。横裂释放完毕之后在最后一个裂节下方的亲本螅状体再生的触手数目可基本确定为8个，由8触手到16触手的转变过程中长势显著。 相似文献
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白色霞水母各发育阶段的形态 总被引：8，自引：0，他引：8
对白色霞水母从受精卵到成体水母各发育期的形态进行了描述。受精卵发育成带纤毛的浮
浪幼虫，浮浪幼虫在定置前形成一种凸面的圆形浮浪幼体囊, 经脱囊狭窄柄部拉长进而变成一个细长颈瓶形状，萌发出4个触手成为早期螅状体；螅状体可产生足囊和通过产生匍匐茎形成囊胞进而发育成新的螅状体；横裂为典型的单碟型横裂；新释放的碟状幼体绝大多数为8个缘叶，8个感觉棍和8对钝圆的缘瓣，但畸形个体最多12个，最少6个缘叶，同时对海蜇与白色霞水母的碟状幼体形态进行了比较。成体水母伞径200～300 mm，大型个体超过500 mm。外伞表面光滑,近中央的伞顶上有许多密集的刺胞丛隆起, 8个缘叶，8个感觉棍,口腕非常发达，口腕上有大量刺细胞团。可根据感觉胃囊和触手囊是否连接、缘瓣水管的排列类型、外伞顶中央是否有刺细胞丛以及个体伞径和颜色对白色霞水母、发形霞水母、棕色霞水母和紫色霞水母进行鉴别。 相似文献
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Bernt Aarset 《Aquaculture Economics & Management (Blackwell Science)》2013,17(2):177-191
Abstract During the past 20 years, Norwegian salmon fanning has grown to achieve export sales of 7 billion Norwegian kroner (NOK). In the same period, Arctic char has been promoted as a lucrative farmed species. Paradoxically, despite the well‐documented advantages of Arctic char farming, this commercial activity has not prospered. Here I study the interaction between research and development and fish farming, and how this interaction affects industrial development within salmon farming and Arctic char farming, respectively. Effective communication between these systems presumes organization by some superior structure that controls the flow of industrial information to the research system, and prepares research results for industrial utility. The focus here is on: the perceptions of industrial actors of tasks for the research community; how researchers interpret and respond to these tasks; how the results are imparted to the fish‐farmers; and how the research results function in practice. I contend that adequate conditions for interaction between research and industrial activity exists for salmon farming, but not for Arctic char farming. 相似文献
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Hervey Rodríguez‐González Alfredo Hernández‐Llamas Manuel García‐Ulloa Humberto Villarreal 《Aquaculture Research》2013,45(1):80-86
The effect of two crude dietary protein (26% and 32% P) and two lipid levels (4.7% and 12% L) on gonadal development of female redclaw crayfish Cherax quadricarinatus was determined. The gonadosomatic index (GSI), hepatosomatic index (HSI), biochemical composition of gonad and hepatopancreas, oocyte diameter and frequency of the developmental stage of oocytes were analysed. The GSI was significantly less using 26% P to 4.7% L. A significant interaction between P and L content was found for GSI. A significantly higher HSI value was obtained when L was 12%. P content in the hepatopancreas was significantly higher using 32% P and 4.7% L. The maximum L content in the hepatopancreas was obtained from the 32% P and 12% L diet. A significant interaction between P and L content was found for L content in the hepatopancreas. A higher frequency of post‐vitellogenic oocytes was obtained with diets containing 32% P. There was an interaction between dietary P and L level causing lipid accumulation in the hepatopancreas and changes in GSI. For an optimum 32% P, excess dietary lipid is bioaccumulated in the hepatopancreas, indicating that there is excess available energy. When the P and L levels are restricted, there is a limited gonad development, thus affecting overall reproduction in female C. quadricarinatus. 相似文献
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Groups of rainbow trout (Salmo gairdneri) fingerlings from five different families and five inbred groups were fed for 153 days on each of four diets similar in energy content, but differing in their percentage of protein. The protein contents were 24, 33, 42 and 51%, respectively. Significant differences between fish families were found for growth, condition factor, chemical composition of the carcass, and digestibility of protein. At the end of the experiment, interaction between diet fed and family was found close to significance for weight and relative growth rate, and significant for length and condition factor. This interaction indicates that prospects for selectively breeding strains of rainbow trout specifically better able to utilize protein are promising.Fish growth rate increased with increasing dietary protein content. The corresponding condition factor, content of dry matter and energy in the carcass decreased. The high protein diets gave more protein in the carcass and a more discoloured liver than the low protein diets. Apparent protein digestibility increased with increasing protein level. 相似文献
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Harun Gülüsoy 《Fisheries Research》2008,90(1-3):70-77
The present study examines the operational interaction between critically endangered monk seals Monachus monachus and artisanal fisheries in the Foça Pilot Monk Seal Conservation Area, Turkey between 1994 and 2002. One to four permanent researchers collected the data on this interaction during the seal sighting data inquiries. Interviews with the fishermen provided 142 direct interactions with monk seals around the fishing gear. Among these encounters damage to fishing gear, including gill nets (53%), trammel nets (37%), longlines (9%) and a lure (1%) was recorded 90 times. However, no difference was found in damage between gill and trammel nets. Although, the damage inflicted by seals per occasion was found to be substantial (maximum 462.5 USD per occasion), the overall annual economic impact on the artisanal fishery was found to be modest. Limitation in soaking time of nets; long-line use instead of nets in MPAs where monk seals survive; and low interest credits to be given to those fishermen who suffer monk seal damage, are proposed as appropriate management practices. 相似文献
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铬对中国对虾仔虾的急性致毒效应及其与铜锌锰相互关系的研究 总被引：1，自引：0，他引：1
在室温适宜、食物充分和氧气充足的条件下,采用目前国内外通用的鱼类毒性试验方法,进行重铬酸钾(K_2Cr_2O_7)对中国对虾仔虾的急性致毒实验以及铬与铜锌锰之间关系的研究。测定了铬(Cr)对中国对虾仔虾的半致死浓度(LC_(50)),并确定了铬与铜、锌、锰之间的拮抗关系。从而,为补充我国“渔业水质标准”和评价水质提供了科学依据。 相似文献
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虾池中日本刺沙蚕的次级生产力研究 总被引：22，自引：4，他引：22
１９９１－１９９２年的５－８月，在辽宁省庄河市总面积４０．１３公顷的六座虾池用Ａｌｌｅｎ和Ｇｒａｙ法估算了日本刺沙蚕总生产量。Ｇｒａｙ法表明，六座虾池沙蚕总生产量平均为４７４．２９（２４０．０１－７９１．０７）ｇ／ｍ＾２；Ｐ／Ｂ系数平均是６．４４（５．４４－７．４４）。在虾池中，沙蚕与对虾间的生产效率平均约为１３（１２－１４．５）。回归分析表明，影响虾池沙蚕生产量的主要因素是沙蚕生物量与水温的交互 相似文献
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介绍了福建省自然保护区发展现状、电子地图与GIS的关系;采用SuperMap和VB相结合的集成二次开发方式成功实现了福建省自然保护区多媒体电子地图集系统.该系统具有丰富的内容、较强的地图显示功能以及独特的交互界面.最后提出了改进图集的要求. 相似文献
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Kaija Saarni Jari Setälä Asmo Honkanen Jarno Virtanen 《Aquaculture Economics & Management (Blackwell Science)》2013,17(5-6):335-343
Abstract In this case study, we describe the evolution of Finnish salmon trout aquaculture; how salmon trout farming grew as a vital industry, how Finland became the world's leading producer of salmon trout, and how the opening of markets to international competition led to a decline of the industry. The focus is on the continuous interaction between the changing market situation and production decisions. The study reveals the impact of national environmental policy on the competitiveness of the industry. At the moment, the industry is undergoing major structural changes; production has moved to neighbouring countries, and the value chain is concentrated. In future, closer interaction and co‐operation between the actors along the entire fish value chain will be the key factors for success. 相似文献