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建鲤的几种疾病及防治钱续(甘肃省榆中县渔业工作站730100)在两年的建鲤引种试验中,观察到建鲤气泡病、小三毛金藻中毒病、烂鳍病、椭圆碘泡虫病及车轮虫病和舌杯虫病。现将观察和治疗情况分迷于后,以供参考。一、气泡病从池边观察,病鱼体色较黑,头朝下,尾朝... 相似文献
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对虾匹里虫超微结构观察 总被引:1,自引:0,他引:1
匹里虫(Pleisotopbora sp)属原生动物门,微孢亚门,微孢子目,单丝亚目,微粒子科。寄生在对虾上的微孢子虫,已报道的有4种,奈氏微粒子虫(Ameson nelsoni)、对虾匹里虫(Pleisotophora penaei)、桃红对虾八孢虫(Agmasoma duorara)、对虾八孢虫(Agmasoma penaei)。微孢子虫病已在我国山东、广东和广西发现,在广东和广西是一种较为常见和危害较大的病, 相似文献
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3.寄生虫性疾病
(1)小瓜虫病(Ichthyophthiriasis)
病原:小瓜虫病是由多子小瓜虫引起的,是斑点叉尾鮰一种危害较大的原虫性寄生虫病。由于病鱼体表粘液增多,游动异常,常见鱼体与固体物摩擦,继而在体表、鳍条和鳃上出现大量小白点,故小瓜虫病又称白点病(White spot disease)。 相似文献
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广东省水生动物疫病预防控制中心 《海洋与渔业》2010,(9):50-50
8月病害发生情况
根据我省各测报点本月水产养殖病害监测数据分析,8月份监测到的主要病害有鱼类出血病、烂鳃病、赤皮病、肠炎病、细菌性败血症、罗非鱼链球菌病、车轮虫病、指环虫病、锚头鳋病、海水鱼刺激隐核虫病和本尼登虫、鳖红底板病和白底板病、对虾白斑病、红体病、桃拉病和固着类纤毛虫病等。 相似文献
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关键种对生态系统结构和功能发挥了重要作用,其变化可以引起群落结构振荡和演替,导致生态系统功能紊乱乃至崩溃,因此,了解生态关键种的长期变化有助于解析整个生态系统演替过程。本研究基于莱州湾1959年、1982年、1993年、2003年和2015年春季(5月)底拖网渔业资源调查数据,构建了莱州湾春季鱼类群落食物网拓扑结构,分析了其关键种的长期变化。1959~2015年莱州湾鱼类食物网包含物种21~46个,摄食关系范围70~296个,食物网拓扑结构密度范围为0.155~0.300,种间关联度0.140~0.182,符合自然条件下群落种间摄食关系。1959~2015年莱州湾鱼类群落关键种如下:1959年为六丝矛尾虾虎鱼(Amblychaeturichthys hexanema)、花鲈(Lateolabrax japonicus)、蓝点马鲛(Scomberomorus niphonius)和黄(Lophius litulon),1982年为鳀(Engraulis japonicus)、黄和小黄鱼(Larimichthys polyactis),1993年为带鱼(Trichiurus lepturus)、鳀和蓝点马鲛,2003年为细纹狮子鱼(Liparis tanakae)、鳀和黄,2015年为细纹狮子鱼、大泷六线鱼(Hexagrammos otakii)和六丝矛尾虾虎鱼;关键种由经济价值较高的花鲈、小黄鱼和蓝点马鲛等演变为细纹狮子鱼、鳀和六丝矛尾虾虎鱼等经济价值较低的种类;同时,关键种的栖息环境也由中上层与底层生境(蓝点马鲛、花鲈、鳀等)演变为底层单一生境(细纹狮子鱼、大泷六线鱼和六丝矛尾虾虎鱼);关键种的这种更替导致食物网拓扑结构向简单化发展,在某种程度上也增加了鱼类群落结构脆弱性。 相似文献
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M. W. APRAHAMIAN P. HICKLEY B. A. SHIELDS G. W. MAWLE 《Fisheries Management and Ecology》2010,17(2):93-105
Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ~1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge. 相似文献
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C.D. de Silva 《Aquaculture International》1997,5(4):339-349
An electrophoretic analysis of six populations of Oreochromis mossambicus (Peters) and four populations of O. niloticus (L.) from several rivers and a fish hatchery in Sri Lanka was conducted to determine the degree of mixing within and between stocks. Genetic characterization of the O. mossambicus stocks showed that some degree of mixing with O. niloticus occurred in all but two of the populations examined, while in the case of the O. niloticus, all the populations had some degree of mixing of O. mossambicus alleles. Genetic identity calculated using Nei's coefficient gave values ranging from 0.9484 to 0.9895 for O. niloticus populations and 1.0 to 0.9940 for O. mossambicus populations, while interspecies comparisons ranged from 0.7531 to 0.9002. The implications of these results for fisheries management and aquaculture are discussed. 相似文献
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为研究斑海豹生长规律,达到科学饲养的目的,对大连圣亚旅游控股股份有限公司豢养斑海豹进行体检,获取动物性别、年龄、体质量和体长等信息;通过SPSS 13.0软件对动物的生长曲线、体长-体质量关系和雌雄间生长差异进行分析。试验共获得30头豢养斑海豹的体检数据,雌性11头,雄性19头。统计分析发现:logistic、Gompertz和von Bertalanffy三种模型回归的斑海豹最大体长、体质量依次为167、170、171 cm和153、175、191 kg ;体质量-体长关系为(r2=0.908);研究还发现体长-年龄、体质量-体长间的相关关系模型能够较准确的反映斑海豹的生长规律,而体质量年龄模型准确度较差。控制年龄的协方差分析未发现雌雄斑海豹生长规律间的差异(体长:P >0.05;体质量:P >0.05)。 相似文献
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César Salazar Marcela Jaime Yanina Figueroa Rodrigo Fuentes 《Aquaculture Economics & Management (Blackwell Science)》2018,22(2):151-167
In light of the current depletion of extractive marine resources and the sustainability issues that have arisen in the aquaculture industry, the small-scale aquaculture sector has emerged as a viable and sustainable alternative for generating income. To integrate the small-scale aquaculture sector into the food value chain, understanding the decision-making process to innovate becomes essential. This paper explores the factors underlying both innovation choices and intensity among small-scale aquaculture producers by utilizing exclusive census data from the small-scale aquaculture sector in Chile. The results indicate that education, secure property rights, internet access, participation in organizations, commercialization methods, government instruments, understanding of credit, and social learning promote innovation decisions. We also find that largest producers innovate in more areas, suggesting a role of size for both technological and non-technological innovations. 相似文献
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Declines in chinook salmon catches in the Strait of Georgia in relation to shifts in the marine environment 总被引:1,自引:0,他引:1
RICHARD J. BEAMISH BRIAN E. RIDDELL CHRYS-ELLEN M. NEVILLE BARBARA L. THOMSON ZIYANG ZHANG 《Fisheries Oceanography》1995,4(3):243-256
Chinook, Oncurhynchus tshawytscha, catches in the Strait of Georgia increased in the 1970s and reached maximum levels from 1976 to 1978. Catches then declined until they stabilized through regulation at levels approximately one-quarter of the 1976 to 1978 levels. The timing of the decline in catch was synchronous with an increase in the mean temperature of the Strait of Georgia, a decline in annual Fraser River flows, and an abrupt decrease in the marine survival of hatchery-reared chinook released into the Strait of Georgia. Surprisingly, the number of young chinook salmon (smolts) more than doubled over the period of declining catches compared with the number produced during the period of high catches. The increase in smolt abundance was a consequence of the production from hatcheries that was approximately equal to wild production. We conclude that there was a change in the carrying capacity for chinook salmon in the Strait of Georgia in the late 1970s that contributed to the declines in abundance and that rebuilding stocks to the high abundance of the late 1970s is unlikely until the carrying capacity for chinook salmon changes either naturally or through manipulation. Although we did not separate density-dependent and density-independent effects on marine survival, the current total number of chinook smolts produced appears larger than required for the current marine carrying capacity. 相似文献
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20 0 1年我们与河北水利厅合作 ,特聘请上海水产大学的专家对我们这里的三座水库进行资源调查 ,专家们认为小海子水库是天然的养蟹基地。这是一个浅碟型平原型水库 ,库底平坦 ,水草丰茂 ,枯水季节生长的水草可达水面 70 %左右 ,底部腐植淤泥层厚 15cm左右 ,水色呈绿褐色 ,透明度在5 0~ 80cm ,日照时间长 ,日照数波动在 12 2 7~2 74 8h ,年平均气温为 13 5℃ ,日平均气温变动在 - 4 7~ 2 8 2℃之间 ,库区最高气温 39 8℃ ,最低 - 13 8℃ ,月平均水温变化为 2 4~ 2 2 9℃之间 ,月平均最高水温在 7月和 8月 ,最低在 12月和 1月。由于水… 相似文献