报刊要闻

<正> 中子辐照技术中子辐照是利用中子的生物效应刺激对虾卵子,促进卵子的孵化、对虾的发育和生长。试验分两部分进行,一是中子辐照对虾卵子,二是中于辐射仔虾。该技术应用于对虾大水体育苗和大面积养成,孵化率高、变态快、抗病力强、仔虾成活率高,     

“低剂量刺激鱼虾生长技术交流会”在山东昌邑召开

1991年9月9日至10日,中国水产学会、中国核学会、中国原子能农学会和山东水产学会在山东省昌邑县共同主持召开了首次“全国低剂量刺激鱼虾生长技术交流会”。近年来,中国农业科学院原子能利用研究所、沈阳农业大学、辽宁省水产研究所、烟台师范学院等单位,先后开展了中子辐照刺激对虾生长的研究和开发利用,他们采用一种新的密封管式14MeV中子辐照装置,用低剂量(1×10~5—1×10~6中子/cm~2)辐照产前亲虾、亲虾卵及虾苗,对其生长发     

对虾人工育苗应用中子辐照技术试验在荣成获得成功

山荣成市海珍品育苗场和烟台师范学院合作进行的科研项目“中子辐照技术在对虾育苗和养成中的应用研究”,于日前在荣成市海珍品育苗场,经有关专家进行了育苗应用的第二次验收。验收结果表明,经中子辐照处理苗池的虾苗,密度大、质量好,成活率比对照池高1.35—2.99     

中子辐照刺激鲢,鳙,草鱼苗增产技术应用初报

中子辐照刺激鲢、鳙、草鱼苗增产技术应用初报戴云福（山东省烟台市栖霞县水利局２６５３００）山东省烟台市科委１９９３年下达给我们的《中子辐照刺激四大家鱼增产技术研究》试验课题，主要是利用低剂量中子辐照刺激鳙、鲢、草鱼、青鱼的鱼卵，对提高四大家鱼的孵化率、...     

中子照射刺激幼蟹生长

80年代，国内外科技人员除利用低剂量电离辐射处理农业作物和蔬菜种子以及鱼、家禽外，还利用低剂量中子照射鱼、对虾卵和扇贝，提高其孵化率和成活率，从此，中子辐射刺激生长技术在水产中得到了应用。但过去的研究中注重鲢、鳙、鲤、草、鲶鱼常规养殖水产品的应用研究，对特种水产养殖方面低剂量辐射刺激生长的研究较少，主要是对虾和青虾。根据江苏省农业科学院原子能研究所罗克勇等人分别对鲢、鲤、鲶、鳗等淡水鱼和对虾、青虾利用低剂量中子辐射刺激生长技术研究的结果表明，在不改变原来养殖条件的情况下，鱼卵孵化率可提高 13. 1％…     

60Co辐照对对虾白斑综合征病毒(WSSV)的灭活效果

以超低温保存的感染了白斑综合征病毒(WSSV)的中国对虾制备的病毒粗提液为毒种，注射感染凡纳对虾并收集濒死虾，DNA斑点杂交检测每尾凡纳对虾WSSV感染状况。取DNA斑点杂交呈强阳性的30尾对虾，平均分为3组，病毒粗提液也平均分成3组，3组材料分别通过^60Co辐照，辐照时间分别为12、24和36h，辐照剂量为0．8KGy／h。辐照后的材料经PCR检测证实^60Co辐照不能完全破坏WSSV的DNA组成。以辐照后的感染白斑综合征病毒的对虾个体和白斑综合征病毒粗提液为感染毒种，人工感染健康凡纳对虾，验证^60Co辐照对病毒感染力的破坏作用，证实^60Co辐照可显著降低WSSV病毒粗提液的感染力，^60Co辐照可适当降低WSSV感染对虾的感染力。     

各地报刊文摘

由江苏省农科院原子能所,中国农科院蚕业所和江苏省淡水水产所共同承担的中子辐照刺激生长仪的研制项目,日前通过省级鉴定。该仪器具有重量轻,结构紧凑,设计合理,交直流两用,机内装有4AH充电电池组,适应在各种生产现场使用。该装置的研制     

论对虾资源增殖的开发研究及增殖试验

<正> 我国在对虾资源增殖的开发研究方面,已经完成了若干技术手段的研究,主要成果是对虾人工繁殖育苗技术、亲虾越冬培育技术,幼虾标志放流技术。利用这些技术成果,已经开发出巨大规模的养虾产业、苗种培育产业,成功地将对虾移植到了东海区,初步形成一支自然种群。还在黄海区的若干水域,用放流幼虾的办法建立了局部海域的对虾增殖事业,取得显著的经济和社会效益。但是用之     

中子辐照刺激生长仪研制成功

由江苏省农科院原子能所,中国农科院蚕业所和江苏省淡水水产所共同承担的中子辐照刺激生长仪的研制项目,日前通过省级鉴定。该仪器具有重量轻,结构紧凑,设计合理,交直流两用,机内装有4 AH 充电电池组,适应在各种生产现场使用。该装置的研制成功为水产、蚕桑等养殖业的发展提供了     

中国对虾血细胞吞噬活动中超氧阴离子（O↓（2）↑（-））的产生

用Zymosan A对中国对虾（Penaeus chinensis）血细胞进行体外刺激,用NBT还原法测定血细胞吞噬活动中产生O2^-的过程。结果表明,中国对虾血细胞在经刺激诱导的吞噬活动中有明显的呼吸爆发和O2^-的产生;不同浓度的Zymosan A对血细胞产生O2^-的影响不同。Zymosan A在0.25-1.0mg/ml对随质量浓度的增加,产生O2^-的量也增加,但当Zymosan A质量浓度继续增加到1.5和2.0mg/mL时,产生O2^-的量反而下降。用同一浓度的Zymosan A对不同密度血细胞进行刺激产生O2^-的强度也不同,随着密度的增加,血细胞产生O2^-的量增加。SOD、NEM和碘代乙酰胺（Iodoacetamide）对血细胞吞噬过程中O2^-的产生有抑制作用;Hg^2 、Cr^3 、Pb^2 、Cu^2 和Zn^2 5种重金属离子也能抑制血细胞产生O2^-;不同个体的中国对虾血细胞产生O2^-的能力不同。NBT还原法测定中国对虾血细胞吞噬时产生的O2^-可以作为检测对虾免疫状态的指标。     

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.     

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.     

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.     

低盐海水培育中国对虾幼虾对高盐度海水适应力试验报告

<正> 中国对虾虽为广盐性甲壳动物,但其对不同盐度的适应通常是通过渐变过程来实现的。高盐度培育的幼虾,移入低盐度海水养殖,要行淡化过渡,这是低盐度养殖中国对虾成功所在。反之,低盐度海水培育出的幼虾,能否直接进入高盐度海水养殖未见报告,笔者配合长江口渔场中国对虾增殖研究课题进行了试验,现报告如下:     

Using the Sustainable Livelihoods Framework to Identify Constraints and Opportunities to the Development of Freshwater Prawn Farming in Southwest Bangladesh

A conceptual framework, drawn from an approach to poverty reduction known as the sustainable livelihoods approach (SLA), is applied to understanding the role of freshwater prawn, Macrobrachium rosenbergii, farming in gher (modified rice fields with high, broad peripheral dikes) systems in southwest Bangladesh. Gher farming potentially allows incorporation of a wide variety of crops together with prawn, fish, dike crops, and rice culture. The analysis shows how, in a gher farming context, sustainable livelihoods are achieved through access to a range of livelihood assets, which are combined in the pursuit of prawn farming strategies. The study used the SLA framework as a diagnostic tool to identify ways of strengthening the livelihoods of the prawn farmers.     

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.     

Resistance to vibriosis,production performance and tolerance to stress of the selected giant freshwater prawn (Macrobrachium rosenbergii)

The purpose of this study was to evaluate the resistance to vibriosis, growth, survival and tolerance to stress of the selected prawn, second generation, compared to a non‐selected control. The first generation of selected giant freshwater prawn, which has 10.4% higher of resistance, was used to attain disease resistant freshwater prawn (Macrobrachium rosenbergii) generation through challenge test‐based selection. Resistance test was conducted by infecting the prawn (mean body weight of 10.29 ± 1.40 g) with pathogenic Vibrio harveyi (5 × 10⁵ cfu prawn^?1). The growth and survival of the prawn were evaluated by rearing the two populations of prawn in both nursery and grow‐out phases. Stress tolerance test was done by evaluating the viability of postlarvae exposed to environmental stressors, i.e. temperature, salinity, NH₃ and formaldehide. Post‐challenge survival of the selected prawn (55.0 ± 5.0%) was about 46% higher than that of the control (37.5 ± 7.5%). The survival of the selected prawn in nursery culture (77.16 ± 0.841%) was significantly higher (p < .05) than that of the control (51.31 ± 2.938%), while the survival in grow‐out culture was similar (p > .05). The growth of selected prawn (4.99 ± 0.03% day^?1) was significantly higher than that of the control (4.81 ± 0.05% day^?1). There was no difference between treatments on the tolerance level against the tested environmental stressor. Overall data suggested that the selected prawn showed better performance in growth and resistance against vibriosis.     

基于理解的对虾疾病的诊断与防治的系统设计

深入开展计算机在水产养殖方面的应用，是目前进行水产养殖自动化的主要内容之一，本文介绍了对虾疾病的诊断与防治的系统设计过程，它是经过多年的生产经验编制出来，既简单又实用，用户只需进行简单的数据输入便可对对虾进行诊治。     

Morphological characterization of larval stages and first juvenile of the freshwater prawn Cryphiops caementarius (Molina, 1782) (Decapoda: Palaemonidae) under laboratory conditions

Research has been in progress for several years on various aspects of the biology and ecology of the freshwater prawn Cryphiops caementarius, an inhabitant of rivers in northern Chile. The commercial value of this prawn fomented the accomplishment of studies on its reproduction and development with the aim of producing juveniles under controlled conditions, to be followed by growout to commercial size in managed culture systems. The present study describes larval culture of this species from eggs of gravid females obtained in the field, from the first developmental stage (Zoea I) through the first juvenile stage. The larvae were cultured at 25 °C in UV sterilized water at variable salinities based on the requirements of the developmental stages. Larvae were fed with Nannochloris, Isochrysis and Artemia nauplii as required. This report describes in detail the 18 larval stages of this prawn, as well as its first juvenile form.     

Current status & prospects of farming the giant river prawn (Macrobrachium rosenbergii de Man 1879) in Thailand

Thailand was second only to P.R.China in annual production of giant river prawn. This article briefly describes the seed production of giant river prawn technology in Thailand and notes that broodstock management has paid scant attention to genetic issues. There are, however, ongoing selective breeding programmes on giant river prawn aimed to improve growth and disease resistance. In the conventional culture technology, postlarvae are stocked at a high density and prawns are harvested partially. The cropping period is long and the practice has led to disease outbreaks and deteriorated pond bottoms that result in frequent detection of antibiotic residue. The improved culture technology involves manual sexing of the prawns at 3 months and restocking only the male prawns into new ponds at low density. The technique gives higher yield and reduces incidence of disease and thus the need for prophylactics. The constraints to giant river prawn culture business in Thailand include low yield and a limited export market. The article describes three ways to expand and sustain the business of giant river prawn farming in the country: development of more genetically improved strains; culture of all‐male stock, and new culture techniques.