共查询到20条相似文献，搜索用时 187 毫秒
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1运输器具 根据所要运输的活鱼种类和规格确定运输器具。一般常用的是三层以上的塑料袋(规格为5米×1米)数套、氧气瓶、换水用的直径15～20毫米的塑料管、手抄网、纱窗、聚乙烯绳或麻绳、药物(青霉素、链霉素、硫酸铜、氯化钠等)。运输器具在运输前应备好待用，并检查试用。2运输前的准备2.1详细了解途中路线上各点的水源、水质情况，确定换水地点，制定运输计划。了解天气情况，确定运输日期。2.2运输前应停食至少半天，运输前1小时应将所要运输的活鱼捕捞入网，进行“吊水”，以利于鱼体排清粪便，避免运输途中粪便腐败水质。在困鱼网… 相似文献
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室外无充气无控温条件下比较了换水量及循环水量对锯缘青蟹仔、幼蟹中间培育的影响。试验结果表明：换水量为10％、20％、30％的各组幼蟹存活率分别为60％、65％、79％；4期幼蟹以上变态率分别为46％、65％、79％；在实验设定的换水量范围内，增加换水量具有促进蟹苗生长和提高存活率的作用；日换水量30％基础上增加100．300％内循环和500％／d流水培育的各试验组，在提高蟹苗的存活率方面与对照组差异不显著．但同期蟹苗的平均个体大小有差异。表现为同期蟹苗的规格随循环水量增加而变大；增加换水量和流水培育对于降低氨氮、亚硝酸氮含量及微生物数量有较明显的作用，培育水内循环在这方面的效果不明显。 相似文献
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为了探讨大规格草鱼种的运输方法，用活鱼罐和大塑料袋充氧运输作对比试验，结果２种大容器运输大规格鱼种成活率均高达９９４％以上。 相似文献
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所谓的“塑料袋法”是一种极其简单易行的运输活鱼的方法。全过程只需要一个塑料袋、一个隔离用的箱子、橡皮筋以及纯氧，而这些都是很容易得到的。把盛放了活鱼的塑料袋装入箱子，就可以象正常的货物那样进行海、陆、空运输了。但是，这种简易方法经联邦德国基尔海洋生物科学院的调研，发现其运送活鱼的死亡率还是相当高。经过测定，引起死亡率高的原因有： 相似文献
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光合细菌在鲍养殖中的应用初探 总被引：3，自引：0，他引：3
本试验采用添加光合细菌、减少换水量的方法进行鲍鱼养殖。结果表明，在200L的塑料桶进行盘鲍人工育苗试验中，试验组以每天换水1／3、添加40ppm光合细菌培养液，其养殖效果与采用3倍流水换水量的对照组相当。而在九孔鲍人工育苗的大池试验中，试验池以每天换水1／3添加50ppm光合细菌培养液的养殖效果明显优于对照组，其平均壳长、平均个体重量较对照组提高5％与55％，总育成率较对照组提高20％。 相似文献
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<正>一、换水要适量Z1第一天不换水,以后每日换水一次,换总水量的20%;Z2一日换水一次,换总水量的25%,用80目网箱隔离蟹苗和外排的水;Z3一日换水一次,每次换总水量的30%,用60目网箱隔离蟹苗和外排的水;Z4一日换水两次,每次换总水量的40%,分早晚进行,用40目网箱隔离蟹苗和外排的水;Z5一日换水两次,每次换总水量的 相似文献
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用正交试验法研究了盐度、光照强度、换水量和抗菌素用量4个因素对锯缘青蟹幼体从Z1变态至Z3的成活率和变态时间的影响．并从试验组合中选出最佳条件。结果表明各因素对锯缘青蟹Z1-Z3期潘状幼体成活率影响的大小顺序为：光照强度〉盐度〉换水量〉抗菌素用量,对锯缘青蟹Z2-Z3期潘状幼体变态时间影响的大小顺序为：盐度〉光照强度〉抗菌素用量〉换水量．并得出培育锯缘青蟹前期潘状幼体的最佳条件为：盐庹为25‰;光照强度为170lx;换水量为1／3;抗菌素的用量为0．5×10^-6。在此条件下,54％的锯缘膏蟹幼体可以从五变态至Z3。 相似文献
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《Journal Of Applied Aquaculture》2013,25(2):99-110
The floating fish cage consisted of a PVC pipe flotation frame (4.6 X 9.1m), a solid plastic bag of polyester reinforced polyvinyl plastic (75m3), and an axial flow water pump (1/4 hp gearmotor with 61 cm diameter impeller). Water flow was 7 m3/minute and provided more than 10 exchanges/hour of cage water. During operational tests, the cage performed as expected, although problems occurred with waste accumulations inside the bag, bag collapse from storm waves, and intake screen clogging with macrophytes. Cage construction and installation costs were about $6,000, and electrical costs were $360/year. 相似文献
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An experiment was carried out to study the effects of anaesthetics (2-phenoxyethanol, quinaldine sulphate, metomedate and MS-222) on water parameters during simulated air transport of platyfish. Xiphophorus maculatus (Günther). The platyfish were put in sealed plastic bags, one-quarter full of water, to which a required amount of anaesthetic was added. The rest of the bag was filled with oxygen. The water in the bag was tested for pH. total ammonia and carbon dioxide at intervals of 4 and 8 h for a period of 48 h. Mortality rates within this period and the post-packaging period were also noted. It was found that 2-phertoxyethanol was most effective, followed by quinaldine sulphate, in decreasing the excretion of metabolic wastes by the fish. Metomidate had no effect in the control of waste production. MS-222 reduced ammonia excretion but not carbon dioxide. None of the anaesthetics used had any effect on the pH of the water. 相似文献
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Ontogeny matters: Climate variability and effects on fish distribution in the eastern Bering Sea 
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下载免费PDF全文 Analyses of climate effects often ignore differences in life history for individual species. We analyzed a 34‐year time series of eastern Bering Sea fish surveys to evaluate changes in distribution by length and between cold and warm shelf‐wide average water temperatures for 20 species over inhabited depth, temperature, and location. All species showed evidence of ontogenetic migration. Differences in distribution between years with warm and years with cold shelf‐wide water temperatures varied among species and within species at different lengths. For species where shelf‐wide temperature effects were detected, the mid‐sized fish were most active in changing spatial distribution. For aquatic organisms ontogenetic migration occurs because life history stages have different environmental requirements. This study illustrates the need to consider species responses to climate change over different life history stages, and that studies on ecosystem responses should take ontogenetic differences into consideration when assessing impacts. 相似文献
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秘鲁沿岸秘鲁鳀渔场及渔汛分析 总被引：1，自引：0，他引：1
秘鲁鳀(Engraulis ringens)是栖息于东南太平洋沿岸的小型中上层鱼类,了解秘鲁鳀渔场和渔汛的状况有助于渔情预报工作的开展进而实现资源的合理利用。利用2005~2014年秘鲁各港口的上岸量数据,以上岸量(landings)、总捕捞努力量(fishing effort)和单位捕捞努力量渔获量(CPUE)为指标分析秘鲁鳀渔场分布及渔汛;结合二因素方差分析(two-factor analysis of variance)探究渔场月份和纬度上的显著性差异;利用分位数的方法,找出各年的旺汛时间。研究表明,每年的4~6月和11~12月为秘鲁鳀的主汛期;主要的捕捞区域分布在7°S~13°S;渔汛的前中期,上岸量和捕捞努力量有着明显的年间差异,而CPUE在渔汛后期年间差异明显。方差分析表明,不同月份和不同纬度对捕捞努力量[ln(effort+1)]有极显著的影响(P0.01);5月为一年中最主要的捕捞阶段。旺汛期分析表明,第一渔汛阶段的旺汛一般在5月出现,而第二渔汛阶段的旺汛一般在11月出现。研究结果有助于对秘鲁沿岸秘鲁鳀渔场及渔汛的认识。 相似文献
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We present a novel low-cost analysis platform and method for monitoring the behaviour of a fish population (starry sturgeons – Acipenser stellatus) – in an experimental tank using a 3-dimensional array of ultrasound transducers. The platform provides time series of fish positions, allowing for assessment of the dynamics of geometric centre (centroid) of fish population. We demonstrate that centroid evolution represents a sensitive indicator of fish behaviour under conditions varied from normal towards non-physiological limits, e.g. pH, dissolved oxygen concentration, feeding and light.Emphasis has been given to reversible effects i.e. after normalisation of water parameters undergoing “gentle” variations, the fish behaviour returns to the normal/physiological pattern.Fish behaviour was previously assessed by several techniques (e.g. electrical impedance, video monitoring, hydro-acoustics, etc.).To our knowledge, this is the first study that uses ultrasounds to continuously monitor the three-dimensional position of fish, having also the advantage of being independent on water turbidity or light level.We stress on the capabilities of the platform and related method to assess the occurrence of abnormal fish behaviour, revealed by the change over a predefined threshold exhibited by the dynamics of the fish population exposed to stimuli, and to automatically issue a warning alert (in case of e.g. non-optimum water quality), thus making it suitable for remote, cost effective monitoring of fish behaviour supporting an optimised aquaculturing. 相似文献
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Standardized method for the Holmen pellet tester (NHP100) as a tool for evaluating the physical quality of fish feed 下载免费PDF全文
下载免费PDF全文 The fish feed production industry requires reliable methods measuring the physical quality of feed before it is being released to the customer. The Holmen pellet tester (NHP 100) could be adapted for this purpose, but the special characteristics of fish feed require particular care during testing. The aim of the study was to determine the standardized conditions for using the Holmen tester as a tool measuring the durability of fish feed. Screening tests were performed on commercial fish feed samples to assess the effects of temperature, pressure and cleaning the instrument between runs. The operating pressure was found to be the most important factor that can influence the results. The temperature of the operating air can also alter the results; increased temperatures can cause oil to melt and leak from the pellets. Cleaning the instrument between analyses can also affect the results. This study shows that when these factors are maintained at a standardized level, the Holmen pellet tester is a valuable tool for assessing the physical quality of fish feed giving additional information on the quality of feed pellets compared to other durability tests like DORIS. 相似文献
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转变增长方式是我国水产养殖持续发展的必由之路 总被引：5，自引：0，他引：5
水产养殖业是渔业中的重要产业之一,已经成为我国水产品市场供给的主要来源。在回顾我国水产养殖业取得伟大成就的同时,也认识到水产养殖业的发展面临着诸如水资源严重缺乏、耕地资源不断被压缩、水产养殖良种覆盖率水平不高、饲料原料短缺、劳动力不足、水产疫苗和药物发展滞后、质量安全和水产品品质安全等问题。认为唯有转变水产养殖的增长方式才是我国水产养殖持续发展的必由之路,如通过转变现有养殖模式,提高单位水体的产量;转变饲料投喂模式,普及高效环保饲料,开发替代鱼粉的新蛋白源;提高优良品种选育与普及水平;加强疫苗创制能力,扩大其应用范围;转变消费习惯,提升加工与流通领域发展水平等措施。水产养殖产品是我国乃至全世界经济社会可持续发展的刚性需求,政府应从战略高度认识到通过转变增长方式实现我国水产养殖业可持续发展的重要意义。 相似文献
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由蓝绿色裸甲藻(Gymnodinium,sp．)形成的蓝绿色水华是无锡渔区高产鱼池典型水质之一。本文对该藻的形态特征、生态、池塘培育和控制以及对鱼类的影响进行了研究。蓝绿裸甲藻水华具喜温、喜光、喜有机氮肥,喜红褐色水色(生物因子),且对外界环境的变化十分敏感等生态特点。蓝绿裸甲藻水华池的理化条件较差,特别是藻体繁殖过度,极易恶化水质,造成鱼类泛池。采用增施有机氮肥、合理使用增氧机、加水等综合措施可促进和控制该藻的繁殖。经鱼类消化道镜检表明,蓝绿裸甲藻能被鲢、鳙鱼及鲤、鲫、罗非鱼鱼种大量摄食,并被鱼类消化。对无锡河埒渔业一队成鱼池三年统计,蓝绿裸甲藻水华池的鲢鳙鱼净产量比无水华池高33．4～37．5％。 相似文献
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Rossa O'Briain Brian Coghlan Samuel Shephard Fiona L. Kelly 《Fisheries Management and Ecology》2019,26(6):512-526
This study investigated interactions between eco‐hydromorphological state, riparian vegetation cover, water temperature and fish community composition in lowland rivers in Ireland. Physical habitat modification of study sites corresponded with degraded eco‐hydromorphological state (degree of ecological and physical modification) and reduced thermal buffering capacity (greater temperature fluctuation and increased frequency of extreme temperature events). This impact was reflected in the fish community, with a shift from a brown trout‐dominated (Salmo trutta L.) fish assemblage to predominance of the more thermally plastic minnow, Phoxinus phoxinus (L.), and stone loach, Barbatula barbatula (L.). Eco‐hydromorphological state may be a central factor affecting the ability of temperate rivers to resist temperature change in a warming climate and to maintain suitable conditions for salmonids and other cold‐water biota. Strategies aimed at climate change proofing of temperate rivers should focus on preserving or re‐establishing the eco‐hydromorphological processes that create habitat complexity and buffer stream temperature. 相似文献