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不同水系青虾交配苗种繁育及成虾养殖试验 总被引:4,自引:0,他引:4
利用太湖和长江两种不同水系的青虾进行交配,可有效改良青虾种质,增大青虾养成规格。试验分别收购天然青虾幼虾和性成熟天然青虾作亲本,进行2种方式青虾交配的苗种繁育,幼亲虾养成后交配共生产虾苗668万尾,子一代幼虾规格不整齐;性成熟亲本交配共生产虾苗295万尾,抱卵虾受精卵发育基本同步,子一代幼虾规格整齐。成虾对照养殖结果显示, 交配虾上市成虾平均体长为6.4 cm,高出天然抱卵虾子代成虾体长5.7 cm的9%,高出养殖虾仔代成虾体长4.7 cm的36%。 相似文献
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氨氮对脊尾白虾幼虾和成虾的毒性试验 总被引:4,自引:0,他引:4
在水温24℃、盐度31、pH8.1条件下,研究了氨氮对脊尾白虾幼虾和成虾的毒性。试验结果表明,氨氮对脊尾白虾幼虾24、48、72、96h的半致死质量浓度分别为155.81、116.71、92.55、80.40mg/L,氨氮对脊尾白虾成虾24、48、72、96h的半致死质量浓度分别为178.80、156.37、140.28、120.86mg/L。脊尾白虾幼虾总氨氮和非离子氨的安全质量浓度为8.04、0.26mg/L,成虾总氨氮和非离子氨的安全质量浓度为12.09、0.50mg/L。 相似文献
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中国对虾杆状病毒垂直传播途径的研究对切断病毒的传播途径,培育健康的对虾种质资源,具有重要的理论和实践意义。本文利用电镜技术,对中国对虾亲虾的卵巢,卵细胞和无节幼体,溲状幼体,糠虾,仔虾,幼成虾进行病毒检测,结果发现卵巢和卵细胞中有似病毒粒子,无节幼体,糠虾,仔虾,幼成虾有杆状病毒感染,并初步探讨了中国对虾杆状病毒垂直传播的可能性。 相似文献
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生产上一般根据市场需求把青虾规格分为三种:即4.5厘米以上的成虾(40O~440只/公斤)、3~45厘米的中虾(10OO只/公斤左右)和3厘米以下的幼虾(300O只/公斤左右)。这三种虾的市场价格相差悬殊,成虾价为80~90元/公斤,而幼虾价为20一3O元/公斤。因此,在注意提高青虾池塘单产的同时,商品率高低直接关系到青虾养殖的成败和经济效益。我市自1991年首次进行青虾池塘养殖以来,通过调整放苗时间和数量、控制秋景、放置虾笼等技术措施,不断提高青虾产量和商品率.取得了良好的经济效益。到1996年底,青虾养殖面积发展到535亩,其… 相似文献
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澳洲淡水龙虾人工繁殖及高产养殖研究课题是北京市科委1994年下达由北京市水产科学研究所承担的“八五”重点科研项目。该课题对从澳大利亚引进的红螫螫虾、牙别螫虾进行了生物学方面的研究、温室人工繁殖试验及幼虾开日饲料研究,初步摸索从苗种养殖、成虾养殖、虾病防治、生态环境控制、幼虾成虾饲料配方等方面综合养殖配套技术,并对牙别螫虾进行室外自然越冬试验。试验期间,繁育虾苗5万余尾,两亩池塘养殖试验,澳洲淡水龙虾亩产达250公斤以上,成虾平均规格45.6克/只,最大个体达140克。经过三年(1994—1996年)的试验,基本上完成… 相似文献
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1投放幼虾
9-10月每667m^2投放刚离开母体的幼虾3万-5万尾。投放幼虾前对池塘要进行消毒、清整、除野、移植水草,并培肥水质。 相似文献
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Concurrent rice‐shrimp‐crab farming systems in the Mekong Delta: Are conditions (sub) optimal for crop production and survival? 下载免费PDF全文
Catherine Leigh Le Huu Hiep Ben Stewart‐Koster Duong Minh Vien Jason Condon Nguyen Van Sang Jesmond Sammut Michele Astrid Burford 《Aquaculture Research》2017,48(10):5251-5262
The Mekong Delta is the most important rice‐ and shrimp‐producing region for food and economic security in Vietnam. Rice‐shrimp farming is practised where salinity fluctuates substantially between wet and dry seasons. Research points to several potential risk factors for rotational systems, but how these link directly to both rice and shrimp production remains poorly quantified for systems that stock and harvest animals year‐round. We examined water and soil quality of 18 rice‐shrimp‐crab ponds, in which shrimp and crab are grown in both wet and dry seasons, in the Cà Mau Province of Vietnam. Multiple lines of evidence indicated that environmental conditions experienced by both rice and shrimp were suboptimal and contributed to low yields and survival. Year‐round cropping of shrimp and crab was associated with sustained suboptimal salinity, intensified by drought, for the wet‐season cultivation of rice. Although rice seedlings were sown in all 18 ponds, only three had a harvestable crop. Low shrimp production and survival was associated with sustained suboptimal water temperatures (too high), salinity (too high in the dry season and too low in the wet season) and dissolved oxygen concentrations (too low). Food availability and quality may also have affected shrimp production. Improving productivity of rice‐shrimp‐crab ponds in the study region may require (1) separation of rice and shrimp crops and improving efficiency of soil washing practices such that salinity conditions are more suitable for each when grown, and (2) management intervention to increase oxygenation of water, and the availability and quality of food for shrimp. 相似文献
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There is considerable interest in the culture of whiteleg shrimp (Litopenaeus vannamei) in inland low‐salinity water in Alabama and other states in the Sunbelt region of the US. However, the growing season is truncated as compared with tropical or subtropical areas where this species is typically cultured, and temperature is thought to be a major factor influencing shrimp production in the US. This study, conducted at Greene Prairie Aquafarm located in west‐central Alabama, considered water temperature patterns on a shrimp farm in different ponds and different years; and sought possible effects of bottom water temperature in ponds on variation in shrimp survival, growth and production. Water temperature at 1.2 m depth in 22 ponds and air temperature were monitored at 1‐hr intervals during the 2012, 2013, 2014 and 2015 growing seasons. Records of stocking rates, survival rates and production were provided by the farm owner. Correlation analysis and linear mixed model analysis of variance were used. Results showed that hourly water temperatures differed among ponds. The range of water temperature in each pond explained 41% of the variance in average final weight of shrimp harvested from each pond. In conclusion, the results suggest that variation in water temperature patterns has considerable influence on shrimp growth and survival in ponds. 相似文献
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对东海区拖虾作业休渔期的商榷 总被引:8,自引:4,他引:4
根据对历年来东海虾类资源调查和社会调查资料分析 ,提出实施拖虾作业休渔措施的必要性。分析认为 :虾类资源是多种类组成的捕捞对象 ,不同种类生态属性不同、分布海域不同、繁殖期和幼虾出现高峰期不同、渔场和渔期不同等 ,指出拖虾作业休渔期不宜搞一刀切 ,应实行分区管理。北部 (31°0 0′N以北 )以广温广盐种类为主 ,宜实行伏季休渔 ;而南部 (31°0 0′N以南 )以高温高盐种类为主 ,宜在 4~ 5月份休渔。为有利于管理 ,可把拖虾休渔管理权下放给各省 ,由各省根据本省的实际情况确定具体的休渔时间。 相似文献
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利用渤海湾对虾卵子、幼体和幼虾调查资料,引用相对成活倍数的概念,并选择与对虾早期生命有因果关系的水文气象因子,通过相关分析方法分析讨论了水文气象因子变化对对虾早期生命的影响。结果表明,6 ̄7月盐差、5月中旬产卵场现场水温和黄河径流对对虾早期生命影响较明显。 相似文献
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The present authors investigated the impact of farming intensity and the prevailing season on water quality in intensive tropical shrimp farms. The weekly water quality samples from the inlets and production ponds of two commercial shrimp farms operating partial water exchange schedules and representing low and high farming intensities in Thailand (with Penaeus monodon Fabricius production rates of 4 and 9 t ha–1 cycle–1, respectively) were analysed over two consecutive production cycles, covering the wet (monsoon) and dry seasons. Significant differences in inlet water quality between farms occurred only in salinity, temperature and suspended solids. The present authors assessed impacts of farming intensity and season on production pond water quality parameters using: (1) an analysis of variance ( anova ) of measurements in replicate ponds during the final month of the production cycle; and (2) a trend analysis which classified trends in parameters over the cycle as externally or internally determined. The prevailing season was found to have a strong impact on salinity, temperature, pH, nitrate, dissolved reactive phosphorus, total phosphorus and dissolved oxygen in the final month of the cycle. The trends in these parameters were largely externally determined or absent. Nitrite and chlorophyll a were affected by production intensity in interaction with season and showed mainly internally determined trends. This indicates that nitrogen transformation processes responded to input levels as well as seasonal influences. Ammonia was highly variable and no significant intensity or season effects were detected, but trends were internally determined only at high intensity and more pronounced in the dry rather than the wet season. The results indicate strong seasonal effects on water quality in tropical shrimp ponds, direct in some parameters and indirect in others, including those linked to nitrogen transformations. The mechanisms of seasonal variation and the implications of these changes for water quality management call for further investigation. 相似文献
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脊尾白虾杆状病毒病研究 总被引:1,自引:0,他引:1
脊尾白虾是一种野生的经济虾类,广温,广盐,杂食性,分布面极广,繁殖季节长。我们已在其病虾的肌肉,中肠等组织中发现C亚群杆状病毒,其形态结构及宿主的细胞病理学特征均与引起中国对虾,长毛对虾,日本对虾等养殖对虾病毒性流行病的C亚群杆状病毒类同。由此认为,脊尾白虾是我国养殖对虾病毒性流行病病原的常年媒介体。 相似文献
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Nallely Estrada‐Perez Javier M. J. Ruiz‐Velazco Francisco J. Magallon‐Barajas Angel I. Campa‐Cordova Alfredo Hernndez‐Llamas 《Aquaculture Research》2020,51(1):242-254
The production of Litopenaeus vannamei was analysed when affected by the acute hepatopancreatic necrosis disease using a dynamic stock model and primary data of seven production cycles from a shrimp farm in Mexico from 2013 to 2016. Significant results (p < .05) of the correlation analysis indicated that during those years mortalities by the disease were more severe when water salinity was high and productivity was low. Significant results from ANOVA showed that throughout the period, disease severity and salinity diminished while pond productivity initially declined but subsequently improved. Significant results from regression analyses conducted for each production cycle also indicated the importance of salinity and productivity on disease severity and showed that early mortality by the disease occurred in ponds with warmer water. Within the observed range of water quality parameters, increases of 1 cm in water transparency and 1 g/L in salinity resulted in increments within 0.17%–0.25% and 1.7%–3.1% in shrimp mortality by the disease. When increases of 1°C in water temperature were recorded, outbreaks occurred 0.2–1.57 weeks earlier. In conclusion, the disease strongly determines the dynamics of shrimp production, and the role of salinity, productivity and temperature is worthy of further delving. 相似文献
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刀额新对虾工厂化育苗技术 总被引:3,自引:1,他引:2
培育刀额新对虾无节幼体时以单细胞藻类作开口饵料,有利于提高成活率;糠虾期、仔虾期在低盐度(S18.66)中生长速度快于在高盐度中,且在逐级递降的淡化过程中,仔虾的成活率较高,这期间投喂轮虫,适合于糠虾、仔虾捕食,轮虫蚕食水中的有机碎屑,有利于水质的改善。 相似文献
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温度、盐度交互作用对凡纳滨对虾耗氧和氨氮、磷排泄的影响 总被引:5,自引:0,他引:5
以凡纳滨对虾(Litopenaeus vannamei)成虾为研究对象,设计了4个盐度梯度和4个温度梯度,采用正交试验,研究了温度、盐度及其交互作用对凡纳滨对虾耗氧率和氨氮、磷排泄率的影响.凡纳滨对虾在温度和盐度交互作用下耗氧率为0.266~0.582 mg/(g·h),平均为0.419 mg/(g·h);磷排泄率为0.935~2.279 μg/(g·h),平均为1.532 μg/(g·h);氨氮排泄率为1.222~2.656 μg/(g·h),平均为1.854 μg/(g·h).统计分析显示,温度和盐度对耗氧率和氨氮、磷排泄率都有极为显著的影响(P<0.01),且两者之间交互作用极其显著(P<0.01). 相似文献