日本对虾亲虾促熟及高效稳产育苗技术

1。亲虾挑选：要选择活力好、体表亮泽、斑纹清晰、甲壳无外伤、附肢完整、已交尾的亲虾。卵巢发育处在Ⅱ-Ⅲ期、体重100克左右为佳。偏大的亲虾虽然产卵量大，但成活率低，特别不耐长途运输。一点都看不到性腺的亲虾成熟较慢，但已发育到Ⅳ期以上的亲虾较难运输，成活率很低。     

影响亲虾暂养成活率几个因素的初步探讨

亲虾是对虾育苗生产的基础。近几年来,随着对虾苗种生产的发展,购运亲虾逐渐增多,但亲虾运距离运回入池后时常发生大批死亡、造成暂养成活率降低。对此,笔者近两年在中捷农场从事对虾育苗工作期间,结合生产进行了初步探讨。一、水温差对亲虾人池成活率的影响四月中、下旬,山东亲虾经过长途运输抵达育苗场时,帆布篓内水温与本地水温有     

提高对虾幼体成活率之浅见

提高对虾幼体成活率,除了必须具备性腺发育良好的亲虾、适口性好及营养丰富的饵料外。还要注意产卵亲虾的数量、产卵时间的控制,并加强育苗期间水质、水温及对虾育苗密度的控制及管理。     

日本对虾亲虾南方北运之技术

日本对虾(Penaens Japonicus Bate)亲虾主要来源于自然海区的海捕对虾,我国主要分布在东海和南海.北方地区进行工厂化人工培育日本对虾苗种,亲虾的长途运输极为重要,没有亲虾或亲虾质量不好,苗种生产即无从谈起.近几年,我们从广东、福建等沿海地区运输日本对虾亲虾,成活率平均达到89.8%.现总结如下. 　　……     

日本对虾亲虾催熟培育方法

日本对虾的亲虾主要来源于广东惠来以及闽南金三角沿海。经长途运输后、若处理不当，亲虾死亡率高，促熟培育艰难。现介绍笔者几年来在这方面的做法。一、缓慢升温，增强体能亲虾运抵育苗场后，暂养池的水温与运输的水温，温差不宜超过2℃。当晚不升温，加大充气量，少量投饵。翌日开始升温，幅度2～3℃／天，并投喂亲虾爱吃的饵料沙蚕。第三天升温速度可以加快，到傍晚升至25C，并投足饵料，投饵率15％～20％。二、眼柄处理经过2天育肥的亲虾，其活力增强，此时应进行眼柄切除手术。眼柄处理时要紧握、看准、迅速，尽量减少因挣扎而造成脱…     

青虾活虾长途运输新方法

青虾活虾长途运输有塑料袋充氧法、帆布篓法、活水船法。三种运输方法各有优缺点，塑料袋充氧运输，成活率高，但操作繁，成本高。如运输1000公斤活虾，至少需塑料袋1000只左右，纸箱500只以上。且塑料袋、纸箱耐久性能差，尤其是纸箱一、二次就全部报废。帆布篓运输．运虾数量少，若行程100公里以上，则成活率较低。活水船运输，时间长，路途水质变化大。以上三种运输方法，对于青虾产量不高的地区或运输亲虾、虾苗，是较为适宜的，但对于地处鄱阳湖畔、年产青虾1000吨以上，且一年四季均需要运输的余干县来说，就不那么适合。近几年来．我…     

几种药物防治人工越冬亲虾纤毛虫的试验

日照市自1984年开始进行亲虾人工越冬生产试验,由于在人为的条件下控制,水温低,时间长,亲虾的相对密度大,体质又弱。因此,在越冬期间容易发生多种病害。为此,近三年来我们对日照市20多处亲虾越冬单位出现的常见病害进行了不同种类药物试验。个别病害已有药物可治,基本上达到“药到病除的效果”。越冬亲虾成活率从1987年的62.99‰,上升到1989年的80%。     

罗氏沼虾亲虾越冬及产前培育技术

本文介绍了罗氏沼虾新虾亲在江西越冬及产前培育技术。在江西气候条件下，面积为１００ｍ＾２的越冬池，亲是越冬密度为２１～２４尾／ｍ＾２或０．３～０．５ｋｇ／ｍ＾２，越冬时水温控制在１９．０～２１．０℃之间，经４个月左右时间，越冬成活率在７０％以上。产前强化培育后亲虾抱卵率最高时可为３１．７％～３６．８％。从池塘养殖的成虾中挑选亲虾可不辨雌雄。     

墨西哥湾扇贝活体长途运输的方法研究

通过对墨西哥湾扇贝活体在16、12、8和4℃不同水温梯度薄膜袋带水充氧运输，其对应耗冰量、时间及成活率进行了比较研究。结果表明水温4℃一次充氧历时72小时，成活率为96％，恒温4℃比较适合扇贝薄膜袋带水充氧长途运输。     

日本囊对虾亲虾无水包装技术与应用

本文报道了以冷冻木屑为填充料,长途运输日本囊对虾（Marsupenaeus japonicas）亲虾的无水包装技术及其应用实验。亲虾在室温条件下经3-5h适应性暂养后,以1℃·h^-1降温速率逐步降至15℃,并维持该温度。包装前1h再把水温降至亲虾出现僵硬或侧卧为冷休克标志,大约11℃左右。包装时,在泡沫箱内铺上冷冻木屑3～5cm,再放上一层排列整齐的亲虾,如此一层木屑一层亲虾,至表层以木屑装满箱为止。一个航空运输专用箱（60×45×32cm）可装70-80尾亲虾。箱内可根据运输时间放置降温剂（干冰）1-2块。2004年-2006年,从厦门空运亲虾到河北黄骅市渤海水产资源增殖站,36批次,亲虾总数量达16584尾,运输过程死亡1436尾,存活率为91.34%。文中还就包装过程人为操作不当的影响、常见问题和各种活虾运输方法的利弊进行了分析与讨论。     

Marketing systems of freshwater prawns in three coastal districts of Bangladesh

The present study analyzes the prawn marketing chain before and after the implementation of a Danish-funded project (GNAEP) in three coastal districts of greater Noakhali, southeast region of Bangladesh. The results reveal that, before GNAEP, there was a longer prawn marketing chain with a number of intermediaries who used to share a considerable amount of market margin. However, after implementation of GNAEP, the prawn marketing chain has become shorter with a significant reduction of intermediaries which facilitates direct selling of prawns to processing plants through local Community Based Organizations (CBOs). The present prawn marketing system in the regions is in favor of prawn farmers. Farmers have greater advantages because 1) CBOs provide reasonable market price and actual weight, 2) CBOs can bargain with processing plants as the former are aware of the latest international market prices through Marketing Information System 3) number of intermediaries is lowered and 4) transport and preservation costs are reduced. The displaced intermediaries, some of whom are powerful persons in the society, have again started to influence the prawn market in different ways. This fact has opened up another discussion on how the power structure is shifting in this region and how they are affecting prawn marketing.     

SOCIOECONOMIC ASPECTS OF SMALL-SCALE FRESHWATER PRAWN MARKETING SYSTEMS IN MYMENSINGH,BANGLADESH

An investigation was carried out in Mymensingh region of Bangladesh to understand current practices of freshwater prawn (Macrobrachium rosenbergii) marketing systems. Prawn marketing is almost exclusively maintained by the private sector, where the livelihoods of a considerable number of people are associated with prawn distribution and marketing systems. The market chain from producers to consumers passes through a number of intermediaries. The prawn is a highly valued product in international markets; most of the prawns (60%) are therefore exported, particularly to the USA, Japan and Europe. The rest (40%) of the under-sized prawns are sold to local markets in Mymensingh. The price of prawn depends on quality, size and weight, and grade. In spite of marketing constraints, livelihood outcomes are positive and most of the households of traders (75%) have improved their social and economic conditions through prawn marketing activities. However, concerns arise about the long-term sustainability of prawn marketing due to poor road and transport facilities, inadequate supply of ice, lack of money and credit facilities, and poor market infrastructure. It is therefore necessary to provide institutional, organizational, and government support for a sustainable prawn market.     

The Effect of Biomass Density,Temperature, and Substrate on Transport Survival of Market-Size Freshwater Prawn,Macrobrachium rosenbergii

Abstract

After harvest, adult prawn are often transported for sales to live markets, such as ethnic Asian outlets, in major urban centers. Poor survival during transportation has hindered development and expansion of these markets. Methodologies to increase survival during transport could contribute to industry viability. Three independent trials were conducted. In the first trial, three biomass densities (25, 50 and 100 g/L) were evaluated in 100-L, open plastic containers aerated with pure oxygen and compressed air. Water quality analyses were performed prior to stocking. After 24 hours in the model transport containers, water quality analysis was conducted and all prawn were removed, determined to be alive or dead, and each group weighed and counted. There was no significant difference (P > 0.05) for prawn survival (overall mean 98%) among the three densities. Concentrations of dissolved oxygen and nitrite were not effected by hauling density (P < 0.05). Total ammonia-nitrogen and un-ionized ammonia-nitrogen concentrations increased (P < 0.05) as biomass densities increased, though values remained within what are considered tolerable ranges. In the second trial, the effect of added substrate and temperature on transport survival was evaluated with prawns stocked at the high density (100 g/L). Two water temperatures (21°C and 26°C) with and without substrate were evaluated in a 2 × 2 factorial with three replicate, 100-L model transport containers per treatment combination (12 containers total). Factorial analysis indicated no significant statistical interaction (P > 0.05) between the presence of substrate and water temperature on any measured variable. The main effects of substrate and temperature were then analyzed separately. The presence or absence of substrate had no significant impact (P > 0.05) on prawn survival. However, temperature had a highly significantly impact (P < 0.01) on survival; prawn survival at 21°C averaged 97% compared to 24% at 26°C. The third trial was a commercial verification trial in which 500 kg of live prawn were transported to New York from Kentucky. These data indicate prawn can be successfully transported at 100 g/L for 24 hours when temperatures are maintained near 21°C. Adding substrate to the transport tank appears to provide no benefit.     

Comparative Efficacy of Anesthetics for the Freshwater Prawn Macrobrachiurn rosenbergii

Abstract— The freshwater prawn Macrobrachiurn rosenbergii is a commercially important culture species in the South Central United States. Two major constraints in the commercial culture of the freshwater prawn in the U.S. are poor survival during live transportation of seed‐stock to growout ponds, and live transportation of pond harvested prawn to distant live markets due to the territorial and cannibalistic nature of prawn. The use of anesthetics could possibly improve transport survival; however, to date anesthetic agents have not been evaluated for use with prawn. Two trials were conducted with juvenile freshwater prawn to compare the efficacy of anesthetics commonly used on fish. The first trial was designed to identify the most promising candidates. In Study 1, tricaine methanesulfonate (MS‐222), 2‐phenoxyethanol, quinaldine sulfate (quinaldine), clove oil, and Aqui‐S^TM were evaluated at 25 and 100 mg/L for 1 h in three replicate 10‐L glass containers, containing five juvenile prawn each. Relative sedation level was determined every 3 min for 1 h, then recovery time and survival were measured. In Study 1, MS‐222 and 2‐phenoxyethanol were determined to be ineffective on prawn at all rates tested. Based on their performance in Study 1, quinaldine, clove oil, and AquiS^TM were evaluated at 100, 200, and 300 mg/L in Study 2. Observations were determined as in Study 1. Clove oil and Aqui‐S^TM induced anesthesia faster and at lower concentrations than quinaldine. At the highest treatment rate (300 mg/L) prawn suffered 60% mortality in the Aqui‐S^TM treatment, 13% mortality in the quinaldine treatment, and 0% mortality in the clove oil treatment and control following a 1‐h exposure to these concentrations. Based on these data, Aqui‐S^TM and clove oil applied at 100 mg/L may be suitable anesthetic treatments for prawn. Additional research is needed to determine optimal time and dose relationships to minimize stress during holding, handling, and transportation of prawn.     

Current status of the giant freshwater prawn ( Macrobrachium rosenbergii) industry in China,with special reference to live transportation

The giant freshwater prawn Macrobrachium rosenbergii was first introduced into mainland China by the Chinese Academy of Agricultural Sciences from Japan in 1976. It was cultured at the Guangdong Province Fishery Institute (now as Pearl River Fishery Institute, Chinese Academy of Fishery Sciences). Following these early efforts, giant freshwater prawn culture has gradually spread to northern and inland areas. At this time (2011), China has become the largest producer of giant freshwater prawn in the world. Due to a preference of cooking with fresh aquatic products, Chinese retail markets have developed which have special live‐holding counters. From small rural shops to urban supermarkets and specialty restaurants, live seafoods are commonly available whereby customers pick out the products they wish to purchase and consume. Giant freshwater prawns are produced in over 35 countries throughout the world. They are usually sold either fresh, on‐ice, or frozen. What makes the Chinese prawn industry unique is its focus on a live transportation and marketing model. As a result, numerous innovative live‐transport technologies have been developed which have been key to the success of this expanding domestic industry. In this article, we would like to give a general overview of the giant freshwater prawn industry, its status in China, and the special role live‐transportation has for expanding production of giant freshwater prawns.     

Current status and prospects of farming the giant river prawn Macrobrachium rosenbergii (De Man) in Bangladesh

Giant river prawn (Macrobrachium rosenbergii) farming plays an important role in the economy of Bangladesh. Presently, it is cultured in around 50 000 ha area with total annual production of 23 240 t. Traditional extensive prawn farming has been expanding over the last three decades through the introduction and adoption of improved culture systems, such as culture of prawn‐carps, prawn‐shrimp‐fish and prawn‐fish‐rice as concurrent and rotational systems. Efforts for the development of improved techniques on broodstock management, seed production and rearing and grow‐out of prawn have been made over the last decade. The outcomes are low‐cost feed for broodstock, production of post‐larvae in net cages (hapa), all‐male prawn culture, periphyton based prawn‐tilapia culture, C/N based prawn culture, organic prawn farming, prawn‐mola culture and prawn‐carp‐mola polyculture. Despite the development of culture technologies, a number of challenges for sustainable development of prawn farming need to be overcome to realize the potentials of this promising sector. Good aquaculture practises at all levels and application of measures for quality control and food safety would ensure sustainable development of prawn farming in Bangladesh.     

The potential of mixed culture of genetically improved farmed tilapia (Oreochromis niloticus) and freshwater giant prawn (Macrobrachium rosenbergii) in periphyton-based systems

The production performance of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton‐based systems were studied in farmers' ponds at Mymensingh, Bangladesh. Fifteen ponds (200–300 m² area and 1.0–1.5 m in depth) were used to compare five stocking ratios in triplicate: 100% GIFT, 75% GIFT plus 25% prawn, 50% GIFT plus 50% prawn, 25% GIFT plus 75% prawn and 100% prawn. Ponds were stocked at a total density of 20 000 GIFT and/or prawn ha^?1. Bamboo poles (mean diameter 6.2 cm and 5.5 pole m^?2) were posted in pond bottoms vertically as periphyton substrate. Periphyton biomass in terms of dry matter (DM), ash‐free DM and chlorophyll a were significantly higher in ponds stocked with prawn alone than in ponds with different combinations of GIFT and prawn. Survival of GIFT was significantly lower in ponds stocked with 100% GIFT (monoculture) whereas, that of prawn was significantly higher in its monoculture ponds indicating detrimental effects of GIFT on prawn's survival. Individual weight gains for both species were significantly higher in polyculture than in monoculture. The highest total fish and prawn yield (1623 kg GIFT and 30 kg prawn ha^?1) over 125–140 days culture period was recorded in ponds with 75% GIFT and 25% prawn followed by 100% GIFT alone (1549 kg ha^?1), 50% GIFT plus 50% prawn (1114 kg GIFT and 68 kg prawn ha^?1), 25% GIFT plus 75% prawn (574 kg GIFT and 129 kg prawn ha^?1) and 100% prawn alone (157 kg ha^?1). This combination also gave the highest economic return. Therefore, a stocking ratio of 75% GIFT plus 25% prawn at a total density of 20 000 ha^?1 appeared to be the best stocking ratio in terms of fish production as well as economics for a periphyton‐based polyculture system.     

3种淡水对虾在冻藏过程中蛋白质特性的变化

以目前市场上主要的3种养殖对虾为对象,以肌原纤维蛋白盐溶解度、Ca2+-ATPase活性与蛋白质表面的巯基含量为指标,探讨了不同温度冻藏过程(-10、-20、-30、-40℃)对虾虾肉蛋白质生物化学特性的变化,评价了不同冻藏温度对对虾品质的影响。结果表明,第一,3种蛋白质的冷冻变性指标应用于对虾时出现一定差异。Ca2+-ATPase活性比较灵敏,能较好反映-10～-40℃不同冻藏温度引起的蛋白质变性的程度。肌原纤维蛋白盐溶解度能够反映-20℃以上冻藏过程中蛋白质变性程度的差异,而-20～-40℃的差异难以区分。-10℃冻藏时,肌原纤维蛋白的盐溶解度下降明显,而-20℃冻藏时下降程度较小,-20、-30、-40℃冻藏时肌原纤维蛋白的盐溶解度没有明显区别。-10～-40℃冻藏对于巯基含量变化都不大。第二,冻藏过程中3种对虾蛋白质冷冻变性较轻度,比一般鱼类在冻藏过程中稳定,虾比大部分鱼类更耐冻。第三,冻藏温度越低Ca2+-ATPase活性下降程度越小,-10～-40℃冻藏时其差异性有比较明显区分,表明Ca2+-ATPase活性更适合于虾的质量评价。第四,-20℃冻藏对于虾类是比较经济合理的,实用冻藏温度可取-20℃...     

崂山湾中国对虾(Fenneropenaeus chinensis)增殖放流的效果评价

为了评价崂山湾中国对虾的增殖效果,2012年5月在崂山湾分两批次放流中国对虾15673万尾。2012年7–9月开展了中国对虾跟踪与回捕调查,进行了中国对虾放流苗种存活生长状况、洄游分布及回捕情况的研究,并应用“Bhattacharya”法区分了中国对虾的自然群体与放流群体。结果显示,8月中旬中国对虾放流苗种主要生活在崂山湾中部海域,第1、2批放流苗种的平均体长分别达到144.9、130.5 mm,随着水温的降低,作季节性短距离的由浅水向深水区移动,放流种群和自然种群分别占总群体的92%和8%;由于受到竞争生物及栖息地环境因素的影响,中国对虾放流群体的回捕率仅为0.58%。虽然相比其他海域中国对虾的回捕率较低,但是崂山湾中国对虾增殖放流仍然取得了一定的生态、经济和社会效益。     

罗氏沼虾引种复壮技术的研究

长期以来,国内进行罗氏沼虾人工繁殖一直以池塘饲养的成虾作亲本,由此造成该虾种质退化,养殖经济效益下降.为提高其种质和养殖经济效益,于1996年和1997年从马来西亚引进野生原种繁育虾苗,进行复壮技术的研究.研究结果表明,野生种子代和杂交种子代的体长、体重明显高出本地的驯养种.种群间具有标准差、变异系数、第二步足与体长的比值相对较小、额齿数相对较多的特点.通常野生原种体形细长、体色淡黄透明、摄食旺盛、抗病力强、性成熟个体较大.野生种子代和杂交种子代幼体活力强,摄食旺盛,变态期延长,但人工育苗的难度大.研究结果显示,采用繁育难度相对较低的雌(本地驯养种)×雄(野生种)配组方式繁育杂交苗,难度较小,效果好.