子母兜地曳网的设计与试验情况

子母兜地曳网是在拉网和百袋网的基础上设计而成的,其下纲比普通拉网和百袋网多一道(即子兜纲)在对比捕捞试验中,使用子母兜地曳网,鲤鱼渔获物占捕捞量的52.65％,比普通拉网提高23.74％,而且不影响其他鱼的起捕率。     

湖泊围养区底层鱼网电联合捕捞效果较好

省淡水水产研究所承担的“七五”国家攻关项目湖泊捕捞专题中的中，小型围养区捕捞技术研究，经1986、1987两年的试验，已研究出一种用SM-1型双向脉冲电赶鱼器和底纲带电的SB-1型拉网相结合的网电联台捕捞技术，在200多亩面积的围养区捕鲤鲫等底层鱼效果良好。     

湖泊围养区底层鱼网电联合捕捞效果较好

省淡水水产研究所承担的“七五”国家攻关项目湖泊捕捞专题中的中、小型围养区捕捞技术研究,经1986、1987两年的试验,已研究出一种用SM—1型双向脉冲电赶鱼器和底纲带电的SB—1型拉网相结合的网电联合     

交流电捕鱼在水库中的应用

当前在水库捕捞中通常采用“赶、拦、刺、张”联合捕渔法，虽然这对捕捞中上层鱼类收到了良好的效果，但在库貌复杂，残木、岩石多的水库，这种渔法损网量大，底层鱼捕获率低。1975年，我县19个水库捕捞。中，底层鱼仅占总产量5％，这就影响了放养底层鱼类的积极性。因此，改进现有渔具、渔法，充分发挥水库渔业生产潜力，这是摆在生产和科研部门面前的重要课题。     

底层鱼兜型拉网设计试验报告

<正> 随着养殖渔业的大力发展和人们对优质鱼需要量的迅速增加,淡水底层鱼类的捕捞已成为研究的重要课题之一。笔者在研究了鲤等鱼类的行动习性和淡水捕捞常用渔具的渔捞特点之后,设计并试验的底层鱼兜型拉网(简称底兜网或底兜拉网),获得单网鲤鱼的起捕率在50％以上,同时兼捕的中上层鱼类起捕率达90％的效果。现将设计与试验报告如下: 一、网具设计及其特点 (一) 鱼类行动习性的观察研究鱼类受到渔具惊吓要向水底方向潜游,这是一般规律。鲤鱼等底层鱼类,也要逃向坑洼处或隐蔽物下躲藏。由于底层鱼一般都具有拱泥觅食和打窝栖息的习性,加之水底不平坦,给它们躲避渔具捕捞创造了有利条     

湖泊围网养鱼的赶张结合捕捞技术初探

采用赶张结合捕捞技术,捕捞湖泊围网养殖鱼类。经2网或3网的捕捞后,青鱼、草、团头鱼鲂,鳙等鱼类的起捕率达94％,鲤、鲫等底层鱼类的为35.84～42.17％。     

大水面养殖捕捞方法介绍

<正>每个塘口面积超过100亩通常称作大水面养殖,且大部分主养花鲢、白鲢、鲤鱼、银鱼、鳗鱼、鲫鱼、黄颡鱼、鳜鱼等。大面积养殖以保持水域渔业资源为主,建立高效、健康、环保的养殖模式,其捕捞方法主要有以下几种。一、大拉网捕捞法大拉网是大水面养殖中常用的捕捞工具,由网头、翼网、上下纲绳、浮子组成。根据捕捞水域地理特点确定翼网的宽度,其宽度小的为     

梭子蟹定置三重刺网设计与试验

根据捕捞目标的生物学习性和体型特征,设计了一种捕捞三疣梭子蟹(Portunus trituberculatus)的专用定置三重刺网并进行了生产试验。所设计的刺网主尺度为50.00 m×1.08 m,上纲长50.00 m,下纲长66.00 m;内网衣规格为1 200目×18.5目,目大120 mm;外网衣规格为200目×2.5目,目大500 mm。2015年9月4—26日在莱州湾渔场进行了生产试验。结果表明,新刺网所捕获的三疣梭子蟹平均体重为175.69 g,单位捕捞努力量渔获量(CPUE)为1.61 kg/(片·次),主捕率高,其中梭子蟹产量占总渔获量的99.31%。新设计的刺网,下纲比上纲长32%,网衣底部较松弛,提高了网衣对梭子蟹的缠络性能,因而提高了捕捞效率;内网衣网目较大,利于释放幼鱼,网高较低,减小了捕获中上层鱼类的几率,因此,兼捕率较低,有利于渔业资源的保护。     

截捕“反网”鱼是提高网产的重要措施

“反网”亦称“炸箍”，是我地在成鱼捕捞驱赶鱼类途中，对鱼群因受惊向拦网外逃现象的俗称。惠亭水库渔场1982年利用“赶、拦、刺、张”渔法，第一网次捕捞成鱼18万斤，其中利用15米深的张网捕“反网”鱼11万斤，占网产的61％。第二网次捕捞成鱼10万斤，其中捕“反网”鱼5万斤，占网产的一半。实践证明：截捕反网鱼是提高网产的一条重要措施。     

带电网捕鱼水中电场的分析与设计

<正> 前言带电网捕鱼在我国淡水渔业生产中已经得到日益广泛应用。我们经过实践证明,它在提高劳动生产效率、降低捕捞成本、尤其在提高底层鱼起捕率方面,具有明显的优越性。电极是带电网中一个关键部分。其功能是将电输送到水中以形成水中电场,利用鱼对电的反应来驱赶鱼类,从而达到利于捕捞目的。由于与水中电场相关连因素比较复杂,目前国内采用的“偶极式”电极参数选择时,一般用现场多次试验,反复调整的方法,不但费时费工,而且也难免存在某些局限性。因此,寻找设计水中电场的方法,对于研制、推广带电网作业有着实际意义。我     

水库疏目拖网的设计和试验

在水库捕捞的网具中，拖网所占的比重极小，原因之一在于鲢、鳙鱼游速快，用常规拖网不能满足追捕鲢、鳙鱼的要求。作者于1982至1983年设计和试验了一种改进的四片式疏目双船拖网，其既能够追捕游速快的大个体鲢、鳙鱼，又能释放小个体的鲢、鳙鱼。经过一年来不同季节在两个大型水库中试捕，已初见成效。试验和生产表明：它具有结构简单、重量轻、成本小、操作简便、劳动强度低、生产效果好等优点。     

The effect of fish density and species combination on growth and utilization of natural food in ponds

Abstract. Interactions between bottom-feeding fish (common carp, Cyprinus carpio L., and hybrid tilapia) and a filter feeder (silver carp, Hypophthalmichthys molitrix (Valenciennes)) in polyculture were studied in fertilized ponds with no supplementary feeding. The silver carp were stocked at two densities: 1300 and 2600/ha. Growth rate and yield of each of the species were also compared with those in polyculture of bottom feeders alone, and in a monoculture of silver carp alone, at the same densities. The consumption of natural feed as melabolizable energy (ME) was calculated by the energy balance (requirement for maintenance and growth divided by the utilization efficiency).
Increasing the density of silver carp reduced proportionally their own growth rate, due to the limited amount of food. Above a density of about 1000/ha, silver carp inhibit the growth rate of common carp and tilapia. This inhibition was small at 1300 silver carp/ha, but considerable at 2600/ha. However, the presence of bottom feeders increased the growth rate of silver carp at both densities. Calculated natural food consumption showed that growth interactions between species were brought about through the availability of food. The synergistic effect of the bottom-feeding fish on the silver carp is assumed to be due to the upwelling of bottom nutrients to the upper layers of water by the burrowing of the fish in the mud. Combined yield of all species in the polyculture was highest at the density of 1300 silver carp/ha (2116 kg/ha in 156 days). At 2600 silver carp/ha the inhibition of growth rate of silver carp itself, reduced total yield as compared with the lower density.     

抑制差减杂交法克隆牙鲆变态早期差异表达的基因

单根方是吕泗渔场一种主要的定置作业渔具，其产量占江苏海洋捕捞产量一定的比重。根据监测，自4月份开始，主要经济鱼类幼鱼开始在渔获物中出现，随着时间推移，幼鱼比例逐渐增加。6月份单根方渔获样品中经济鱼类幼鱼尾数比例1990—2004年期间年平均为48．63％，重量比例为35．86％，其中小黄鱼（Larimichthys polyactis）、银鲳（Pampas argenteus）、带鱼（Trichiurus japonicus）尾数合计比例年平均为45．21％，重量合计比例年平均为33．29％。7、8月份样品中主要是小黄鱼、银鲳幼鱼，9月份鱼类幼鱼比例降至20％左右。本文着重对6月份单根方作业经济幼鱼进行了分析，建议对定置作业休渔时间进行调整，以利于保护经济鱼类幼鱼资源。     

POLYCULTURE OF THE FRESHWATER PRAWN (Macrobrachium rosenbergii) WITH TWO COMBINATIONS OF CARPS IN MANURED PONDS

A study was conducted to 1) evaluate the compatibility of prawns (Macrobrachiurn rosenbergii) with carps, especially the effect of the common carp (Cyprinus carpio); and 2) measure the ability of prawns to utilize the foods available in manured systems. Carps used were the silver (Hypophthalmichthys molitrix), bighead (Aristichthys nobilis), grass (Ctenopharyngodon idella) and common carp (Cyprinus carpio). Four ponds (0.09 to 0.17 ha) were stocked with silver, bighead and grass carps while common carp were stocked in only two ponds. Total fish densities were 8,600/ha where four carps were stocked, but only 6,200/ha when common carp were omitted. Post-larval prawns (wt 0.116 g) were stocked at densities of 17/m². Swine (approximately 60/ha of pond surface area) were housed on pond dikes so that fresh manure continuously entered each pond. Two lots of swine were fattened during the experimental period and loadings of swine manure were calculated based on hog size and feed consumption. Growth periods were 163 days for fish and 107 and 121 days for separate stockings of prawns. Gains in biomass by prawns averaged 714 kg/ha in ponds without common carp and 364 kg/ha in ponds containing common carp. Gains in biomass for both fish and prawns were 3,619 kg/ha (19.8 kg/ha/day) in ponds with common carp and 2,924 kg/ha (18.0 kg/ha/day) in those without common carp. Prawn survival was higher (X = 84.5% vs X = 72.5%), but final average weight of prawns was lower (2.64 vs 5.86 g) in the presence of common carp due to competition for food between common carp and prawns. Competition from carp is believed to have exerted less influence on prawn survival than predation on small prawns by larger, faster-growing prawns.     

Movement, social cohesion and site fidelity in adult koi carp, Cyprinus carpio

Abstract  Koi carp is an ornamental variant of the common carp, Cyprinus carpio L., that was introduced to New Zealand in the 1960s and has since become a major aquatic pest. A total of 1265 wild adult koi carp were caught by boat electric fishing, dart tagged and released at multiple sites in the lower Waikato River and associated lakes and wetlands between September 2002 and February 2005. Subsequent recaptures by boat electric fishing and recreational fishing returned 76 koi carp (6% of all tagged fish). Of these, 85% were recaptured less than 5 km from their release site; only one fish moved more than 50 km. On seven occasions, pairs or small groups of koi carp (20% of all tag returns) that had previously been tagged and released at the same locations and times were subsequently recaptured together after considerable periods of time at liberty (mean 551 days ± 419 SD). Adult koi carp in the Waikato River showed a high degree of site fidelity, exhibited prolonged social groupings and females moved downstream more often than males.     

Changes of eel exploitation in Polish lakes

The paper discusses briefly eel exploitation and traditional methods of catching eel. Attention is drawn to changes taking place in eel exploitation in Polish lakes, and to their causes. Most effective methods of eel catching are reviewed. It is pointed out that utilization of active fishing gear, mainly seine nets and electric aggregates, creates significant possibilities of increasing eel catches. Eel yields up to 40 kg/ha are not unusual with this type of gear. Furthermore, active fishing gear is more effective and can be used also in lakes in which it is difficult to apply traditional eel traps. The latter fact is of special significance in view of the increasing number of lakes stocked with eel, and improvement of eel stocking effectiveness.     

尼罗罗非鱼行为习性及其捕捞渔具的设计

尼罗罗非鱼(OreochromisniloticaL.)属热带性鱼类,为我国1978年从国外引进的优良海淡水养殖对象,具有食性杂、生长速度快、肉质鲜美、经济价值高等优点[1]。目前已在我国数个省、市开展养殖。尼罗罗非鱼性喜群游,其最适生长水温为24～32℃,水温降至14℃时,活动迟缓,停止摄食,水温降至12℃以下时便逐渐死亡[2]。因此,在我国北方地区养殖的尼罗罗非鱼,一般在严冬前开始进行捕捞。水温达到20℃以上时,雄鱼会在池边或者池底挖洞,当遇到外界刺激或拉网捕捞受惊后,便潜入洞中或软泥中。尼罗罗非鱼的这一行为习性给捕捞造成很大困难,因此各地一般…     

Intensive polyculture of common carp,Cyprinus carpio L., silver carp,Hypophthalmichthys molitrix (Val.) and black buffalo,Ictiobus niger (Raf.)

Intensive polyculture was carried out with common carp, silver carp and black buffalo fed a mixture of 60% pellets (with protein level of 25%) and 40% barley, along with mineral and organic fertilization. Two stocking patterns were tested. From pattern I, in pond 1 (total stocking density 4600 fish/ha), the yield of fish after 180 days was 3538 kg/ha, with standard weight (above 500 g), at a food conversion ratio of 2.36. From pattern II, in pond 2 (total stocking density 9200 fish/ha), the respective figures were 5022 kg/ha and 2.56.An economic comparison of several polyculture trials showed that buffalo fish (bigmouth and black) at a stocking rate of 2000 fish/ha, grown with common carp (2500 fish/ha) and silver carp (1200–1500 fish/ha), gave the best breeding and economic results (a profit of 962 levs/ha or 0.27 lev/kg). The buffalo fish have excellent organoleptic properties and are considered a delicacy favoured on the Bulgarian market.     

The effect of phosphorus supplementation to common carp diets on fish growth

The effect of supplementation of fish diets with phosphorus was studied both in tank and pond experiments. In the tank experiments phosphorus (6.5% di-calcium or mono-calcium phosphates) was added to three diets: two containing fish meal as the main protein ingredient and the third containing algal meal to replace it. Feeding common carp in tanks with these diets significantly increased fish growth rate (P < 0.05) over fish fed the same diets without phosphorus supplementation. In the pond experiments phosphorus was added to a fish meal diet in two different compounds: mono- and di-calcium phosphates (at 1% of the feed). The diets were fed to fish in a polyculture system for two consecutive culture cycles. Due to supplementation with phosphate, growth rate of tilapia (Sarotherodon aureus) increased in both culture cycles. The growth rate of common carp fed phosphorus-supplemented diets increased over the control only in the first cycle, when fish were large and the standing crop of carp exceeded 1.8 ton/ha. At lower standing crops the natural food seems to supply adequate amounts of phosphorus. Silver carp were not affected by phosphorus supplementation, probably because they consume very little supplementary feed. Total yield for the entire season (kg/ha) was significantly higher in ponds where fish were fed a phosphorus-supplemented diet. Di-calcium phosphate, which is soluble only in weak acids, seems to be more efficient than the water-soluble mono-calcium phosphate in affecting the growth of common carp even though this fish lacks a gastric acid secretion.     

关于渔具分类的研究

本文指出渔具分类的重要性，同时对现有各种主要渔具分类见解进行历史地评价，并着重就“渔法”的定义进行探讨。在此基础上按渔具的渔捞原理提出新的渔具分类系统。本文建议对渔具作类——型——种三级分类，将全部渔具分成11个类：1．投刺、抄捞渔具，2．钓渔具，3．陷阱渔具，4．集捕渔具，5．掩捕渔具，6．刺网，7．敷网，8．张网，9．围网，10．旋曳网，11．拖曳渔具。免除传统的渔具分类中为某些无所归属的渔具而设置的“其他”等称谓的这一类别。