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黄海北部海洋岛渔场，自1985到1987年，累计放流3厘米长的虾苗16亿尾。三年来秋汛累计回捕放流对虾4000多吨，产值1亿多元，回捕率占10％，为出口创汇发展外向型经济作出了贡献。 相似文献
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东吾洋中国对虾的移植放流 总被引：5，自引：0，他引：5
1986～1990年在东吾洋水域放流中国对虾(Penaeus orientalis)种苗70919万尾,其中96.2%是末经中间培育,体长为8～15mm 的仔虾。共回捕对虾917t,年平均回捕率5.02%,优化了东吾洋对虾种类结构和数量组成。东吾洋中国对虾移植性放流增殖取得了显著的经济、社会和生态效益。还探讨了东吾洋中国对虾的放流时间、海区和增殖前景。 相似文献
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黄海北部中国对虾放流增殖渔业目前存在的主要问题佟万金李培军（丹东市渔业指挥部１１８０００）（辽宁省海洋水产研究所大连１１６０２３）黄海北部中国对虾放流增殖从１９８５年至１９９２年共放流平均体长３ｃｍ以上对虾种苗９７亿尾，回捕增殖虾１７９００多吨（包括... 相似文献
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海洋岛渔场对虾增殖放流现状及对策 总被引：3，自引：0，他引：3
海洋岛渔场是黄海北部的重要渔场。自70年代末期，该渔场资源严重衰退，大部分经济鱼类已濒临绝迹，尤其是对虾已不能形成渔讯，年捕捞量由最高年份5000吨，下降到最低年份40吨左右。为尽快恢复对虾资源，我省自1985年开始在海洋岛渔场进行大规模对虾增殖放流，15年来投入资金近1亿元，累计投放对虾苗149亿尾，回捕对虾2．4万吨，创社会总效益10亿元，投入产出比为1：10，取得了明显的经济效益、社会效益和生态效益，对恢复对虾资源，确保沿岸渔民收入稳定，调整产业结构，促进我省增殖渔业发展起到了重要作用。回顾15年的对虾增殖放流工作… 相似文献
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分３个阶段总结黄海北部中国对虾放苗增殖效果，第一阶段（１９８５～１９８８年）放流效果好，回捕率高，平均投苗量７．６亿尾，平均捕捞产量２２００吨，平均回捕率约１１．６％，第二阶段（１９８９～１９９２年）放流数量多，但回捕率低，平均投苗量１６．７０亿尾，平均回捕率约６．７％，第三阶段（１９９３～１９９５年）平均投苗量７．１８亿尾，平均回捕率约２．３３％，回捕效果极差，下降原因：一是客观原因造成，如污染 相似文献
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一、国内外对虾放流增殖简况 据有关资料报道，日本濑户内海在70年代初期，对虾产量仅为466吨，尔后通过每年向海湾投放虾苗1-1.5亿尾，到1975年使对虾产量上升到1230吨．我国渤海湾在80年代进行中国对虾人工增殖，把体长3厘米的虾苗放流入海，经70天左右可以生长到16厘米，回捕率达10%以上，据推算每放流工万尾虾苗，可增产对虾35公斤， 相似文献
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为探究中国明对虾(Fenneropenaeus chinensis)增殖放流对水域内鱼类的影响及其表现形式,采用原位实验生态学方法,在对虾放流河道构建围隔,设置3种虾苗放流量(模拟莱州湾近岸放流5亿尾、7.5亿尾和10亿尾)和无放流处理,经过一个对虾生长季后,比较不同处理围隔中鱼类组成和生态位特征差异。结果显示,4种处理围隔中,回捕对虾数量随放流量增加而增加,但其生物量、平均个体大小和回捕率未随放流量增加而增加;回捕率在放流围隔间差异显著,以5亿尾模拟围隔的值最高;鱼的种类组成相似,可归于杂食性、浮游动物食性和鱼/虾食性。总鱼类和鱼/虾食性的鱼类产出量在围隔间差异不显著,杂食性鱼的产出量以放流围隔较高,浮游动物食性鱼的产出量随对虾放流量增加而减少。鱼种间高生态位重叠(>0.75)配对数随对虾生物量增多而减少。相似性分析显示,放流最多的和无放流围隔的鱼类生态位相异程度最高。综上认为,在实验水体中,放流对虾并不降低鱼类总量产出,但可能会影响不同食性鱼类的相对组成和生态位重叠度,且影响效应随放流量增加更为明显。 相似文献
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浙江省海洋牧场研究的现状 总被引：1，自引：0，他引：1
从八十年代开始以来,浙江省十分重视海洋牧场的研究工作,在象山港、三门湾海域进行人工放流中国对虾,近10年,共放流了3cm规格的中间培育虾苗11亿尾。象山港和三门湾每年各放流虾苗1亿尾,根据回捕率测算,回捕率为8—10％。 相似文献
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“太湖1号”杂交青虾规模化繁育技术研究 总被引：2，自引：0，他引：2
利用53hm2标准化鱼池,采用雌雄亲虾同池的放养模式与集中投放抱卵虾孵化培育模式2种模式进行“太湖1号”杂交青虾的规模化繁殖试验。结果显示,本期共繁殖生产虾苗33533．86万尾,31878．33kg。雌雄亲虾同池培育的产苗量比集中投放抱卵青虾培育的产苗量要低36．49～69．26kg／hm2,或132．85万。143．607万尾／hm2,苗种规格大小差异大。雌雄亲虾同池培育的捕苗时间从7月18日到8月25日,共计38d,集中投放抱卵亲虾培育池的苗规格较一致,捕苗时间为期25d,捕捞时间缩短了13d。这表明,集中投放抱卵虾孵化培育模式可作为青虾规模化繁殖生产的优选方式。 相似文献
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鱼塭即北方所谓“港”,是一种人工围海筑成的咸水和海水水塘,面积大小不一,广东沿海及河口地带,利用这种水体进行角、虾养殖极普遍。鱼塭养殖方法在我国已有300多年历史,到解放以后有了很大的发展。这种养殖所用的鱼、虾种苗,是依靠在适当时间开放闸门,利用涨潮时塭内外水位差,将塭外海水灌入塭内时引进去的。 相似文献
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The effects of two selected probiotics ( Pseudomonas synxantha and Pseudomonas aeruginosa ) on the specific growth rate (SGR), survival and immune parameters of juvenile western king prawns ( Penaeus latisulcatus ) were examined for 84 days. Pseudomonas synxantha and P. aeruginosa were either applied into the rearing medium or supplemented in the formulated feed at a concentration of 105 colony forming unit (CFU) mL−1 for each probiotic. The results showed that applications of the probiotics resulted in no significant difference ( P >0.05) in the SGR and survival of the prawns, but significantly decreased the food conversion ratios ( P <0.05) compared with the control where no probiotics were applied. The supplement of the probiotics with the formulated feed enhanced the probiotic numbers in the intestines of the prawns and low bacteria numbers in the haemolymph. The prawns were significantly ( P <0.05) healthier, as indicated by the immune response obtained when both probiotics were given in combination compared with when individual probiotics were used. When applied singly, P. aeruginosa resulted in a higher health status of the prawns compared with P. synxantha . Overall, equal combinations (105 CFU mL−1 ) and volumes of P. synxantha and P. aeruginosa used as a supplement in the formulated feed resulted in an improvement in the health of the juvenile western king prawns. 相似文献
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Abstract— Juvenile Penaeus monodon prawns were bathed in seawater-formaldehyde concentrations of 312, 625, and 1,250 ppm for up to 6 h. The tests were conducted at concentrations in excess of those previously published, in order to examine maximum tolerance levels to formaldehyde. Physiological stress was monitored by measurement of blood glucose levels. Under controlled laboratory conditions, 12 h food deprived juvenile prawns exposed to formaldehyde concentrations of 312 ppm did not exhibit signs of stress. However, bathing in formaldehyde concentrations of 625 and 1,250 ppm, caused significant increases ( P < 0.05) in blood glucose levels after 2 and 4 h, respectively. There were no mortalities in any treatment group. In contrast, juvenile prawns from grow-out ponds bathed in 625 ppm of formaldehyde immediately after 2.5 h of transport did not exhibit significant increases in blood glucose. This may be due to their nutritional status and these results are discussed. No significant change in blood glucose levels was observed in bilaterally eyestalk ablated prawns after exposure to 1,250 ppm formaldehyde. The increase of blood glucose due to formaldehyde treatment is presumably mediated by a stress response, which includes crustacean hyperglycemic hormone (CHH), and not a result of non-specific cell lysis and death. 相似文献
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Effect of Bacillus subtilis on Aeromonas hydrophila infection resistance in juvenile freshwater prawn, Macrobrachium rosenbergii (de Man) 总被引：1，自引：1，他引：0
This experiment was carried out to investigate the potential probiotics properties of Bacillus subtilis in protecting of juvenile freshwater prawn, Macrobrachium rosenbergii against Aeromonas hydrophila infection. A B. subtilis bacterium isolated from gut of juvenile prawns was added to the prawns feed at 108 cells g?1 feed. There were significant differences (P < 0.05) between B. subtilis-treated and control groups in growth and survival enhancement of juvenile prawns after 60 days of feeding trial. Sixty days after B. subtilis feeding trial, the prawns were challenged by bath exposure to A. hydrophila (107 cells mL?1) for 28 days. Four weeks after challenge, there was significant difference in the survival of prawns between B. subtilis-treated groups (88.33 %) and control groups (20.81 %; P < 0.05). In addition, the control groups had an unhealthy external appearance, while the treated groups, appeared healthy and normal. From this, it was concluded that the selected B. subtilis may be a promising probiotics for protection of prawns from A. hydrophila infection. 相似文献
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Production Characteristics of All‐male and Mixed‐sex Giant River Prawns,Macrobrachium rosenbergii,Grown in Earthen Ponds in Kentucky and Mississippi USA 
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下载免费PDF全文 James H. Tidwell Louis R. D'Abramo Shawn D. Coyle Leigh A. Bright Charlie Shultz Zachary Kupchinsky Pamela Schwartz Craig Upstrom 《Journal of the World Aquaculture Society》2015,46(2):139-148
Production and population characteristics of monosex male (all‐male) giant river prawns, Macrobrachium rosenbergii, were compared with a normal (mixed‐sex) population in separate studies in Mississippi and Kentucky (USA) under low and high density stocking conditions, respectively. In Study 1 (Mississippi), juvenile prawns were stocked into eight 0.05–0.06 ha ponds at 24,700/ha. The mean stocking weight of all‐male was 0.34 g and mixed‐sex was 0.39 g. Prawns were fed 23% crude protein “range cubes” and harvested after 120 d for the all‐male prawns and 112 d for mixed‐sex prawns. In Study 2 (Kentucky), juvenile prawns from each group were stocked into six 0.04 ha ponds at 60,000 juveniles per hectare. The mean stocking weight for all‐male was 0.38 g and for mixed‐sex juveniles was 0.34 g. Prawns were fed a commercial sinking pellet (33% protein) once daily at a standardized rate and harvested after 105 d. In both locations survival of mixed‐sex prawns and all‐male prawns was not significantly different and the final average weight of all‐male prawns was significantly greater than the average weight of mixed‐sex prawns. For the study in Kentucky, total production was not significantly different between treatments, whereas in Mississippi total production in the all‐male ponds was significantly higher than in the mixed‐sex ponds. For both studies, the production size index of all‐male prawns was significantly greater than that of mixed‐sex prawns. In terms of population structure, in all‐male ponds there was a significant increase in orange claw (OC) males compared with the mixed‐sex ponds both as a percent of sex and a percent of total population. The increase in OC numbers in all‐male populations may be due to a lack of females to stimulate the transition of males to the final, sexually mature, blue claw stage. As target weights increase from 20, 30, and 40 g, the all‐male populations were increasingly superior in terms of production (kg/ha) of those target sizes. The economic benefit of all‐male over mixed‐sex populations will be principally based on an examination of tradeoffs that primarily consider the cost difference of juveniles relative to the price differences for different final harvest weights. 相似文献
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Ilan Karplus Elvira Samsonov Gideon Hulata Ana Milstein 《Aquaculture (Amsterdam, Netherlands)》1989,80(3-4):325-335
The effect of claw ablation on the growth and survival of juvenile Macrobrachium rosenbergii was tested; two sets of controls were used consisting of a group of intact prawns, and an additional group whose first pair of walking legs had been ablated so as to serve as controls for injury and regeneration. Survival among claw-ablated prawns was twice as high as that for the two control groups. Intact prawns weighed more than those with ablated appendages. During the experiment the coefficient of variation of mean weight decreased in the claw-ablated group. It increased in the intact prawns and was relatively stable in the group with ablated first pair of walking legs. The biomass of the claw-ablated group doubled within the test period while that of the controls was stable because the gain in mean weight and the mortalities counterbalanced each other. 相似文献
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A stocking density experiment was conducted in 18 experimental enclosures within a single 0.11 ha pond. As stocking density increased in the range 6.1–21.2 prawns/m2, school prawn growth declined while survival rate was unaffected and total harvest (final biomass) increased. A simple economic analysis indicated that the optimum stocking density for juvenile school prawns was 19.1 prawns/m2. In a similar experiment the effects of feeding school prawns with a pelleted diet at a range of supplementary feed rates (0–12.5% of prawn biomass/day) were investigated. The optimum feed rate in terms of growth was approximately 5% of biomass/day. However the optimum feed rate, in terms of the economic return index used, varied depending on the estimated cost of the diet. 相似文献
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Rapid salinity changes affect the survival and physiology of a penaeid prawn: Implications of flood events on recruitment to the fishery 下载免费PDF全文
下载免费PDF全文 K. J. Tyler A. Becker N. A. Moltschaniwskyj M. D. Taylor 《Fisheries Management and Ecology》2017,24(6):478-487
Estuaries act as nurseries for many penaeid prawns, but these habitats are highly susceptible to salinity decline through flooding. The rate of salinity decline and duration of exposure to non‐optimal salinity may affect survival and subsequent recruitment of prawns to the fishery. This study aimed to determine the effect of salinity fluctuations observed in local estuaries during flood events using a novel dilution approach. Mortality of juvenile Melicertus plebejus (Hess) was assessed after 24 hr exposure to 24 rates of salinity decline ranging from 0.01% to 20% per hr. After the salinity decline, prawns were held at the final salinities for five days before again assessing mortality as well as aerobic metabolic rate and prawn water content. Salinity decline from 36 to ~0.8 led to 50% mortality, but continued exposure to low salinity for five days increased mortality at this salinity to 99% and shifted the 50% mortality point to salinity ~5. Aerobic metabolic rate and water content data suggested the cause of mortality due to exposure to salinities < 5 was osmoregulatory failure. Rapid salinity declines over 24 hr and sustained low salinity due to flooding could compromise the survival of juvenile prawns, potentially reducing recruitment to the fishery. 相似文献