合理利用增氧剂解决越冬鲤鱼大批死亡问题

我们总结了最近2～3年越冬池塘的发病情况,特别是越冬鱼池大批鲤鱼死亡、而鲢鳙却很少死亡的问题,经过几年的实践,认为越冬池适当利用增氧剂和机械增氧相结合的方法对解决越冬鲤鱼大批死亡的问题有很大的帮助。比较越冬鲤鱼大批死亡的越冬池,我们看到这些池塘多存在着换水不便、池塘水质老化等现象。     

在水库利用网箱越冬鲤鱼种试验总结

为了大力推广网箱养鲤，需要培育出大量的合格的鲤鱼种。但在我国“三北”地区，由于冬季结冰越冬池塘数量有限，如果不解决大面积大批量鲤鱼种越冬问题，那么推广网箱养鲤也会成为一句空话。1981-1983年我场曾利用网箱在水库进行了鲢、鳙鱼种越冬试验获得成功。随着网箱养鲤的发展我们于1985年进行了网箱越冬鲤鱼种的试验。在总结1985年网箱越冬鲤鱼种的经验教训，     

芝罘湾网箱越冬鲈大批死亡探因

分析了芝罘湾鲈网箱越冬大批死亡的原因，主要由鳗弧菌侵入鱼体所致。提出了预防鲈越冬死亡的措施。     

书讯

培育好鱼种，并让其顺利度过严冬，是池塘养鱼的一个重要环节。但不少渔农对鱼种越冬缺乏足够的认识，结果由于管理不善，造成大批死亡。要想使鱼种越冬成活率高，必须采取下列技术措施：     

池鱼的越冬管理

我国北方地区冬季池塘结冰期达数月之久,如果忽视管理工作,往往造成大批池鱼死亡。因此,加强越冬期的管理是保证池鱼安全越冬的关键一环。     

鲤鱼种越冬死亡原因的调查与研究

本文对越冬期池塘出现的鲤鱼种大批死亡事故进行了全面、系统地调查与现场监测，找出死鱼的主要原因并采取了相应的技术措施，使越冬成活率从０￣５０％提高到８３．３％以上。     

水库网箱与池塘越冬鲤鱼种的对比试验

在大绥河水库越冬鲤鱼种１４箱，计２１３３６ｋｇ，与池塘越冬３．０６ｈａ，鱼种２８８６１ｋｇ进行对比试验，结果网箱越冬鱼种成活率８１．０９％，鱼池鱼种成活率２７．０９％，网箱越冬费用仅为池塘越冬费用的２２％，表明前者能提高鱼种越冬成活率，降低用，增加经济效益。     

精养高产池塘冬季死鱼的原因及预防

近年来，随着淡水渔业持续、快速发展，山东省的淡水养殖业亦进入了一个新的发展阶段，集约化精养高产成为淡水重要的养殖模式。然而，精养高产池塘冬季大批死鱼情况却越来越严重，为此，我们对精养池冬季死鱼原因和预防方法进行了调查研究，以期达到提高越冬成活率，减少死亡，增加经济效益之目的。     

再谈池塘鱼类越冬死亡原因及对策

近年来池塘越冬死鱼的事时有发生,如何保证池塘鱼顺利越冬,提高越冬成活率是广人养殖户十分关心的问题,因此将越冬死亡的主要原因和对策介绍如下,以供广大养殖户参考。 一、缺氧 在一般情况下,越冬水体,严重缺氧是造成鱼类死亡的主要原因,造成缺氧的原因有以下几个方面:     

西北地区养殖甲鱼越冬死亡原因分析与预防

我国西北地区冬季气温偏低,池塘封冻与甲鱼冬眠期较长,人工养殖甲鱼在每年越冬期间均出现体质衰弱及大量死亡现象,笔者分析养殖甲鱼越冬死亡的原因,并总结预防措施如下,以供同行借鉴。 一、甲鱼越冬死亡原因分析 1.水质原因 一方面,池塘封冻时间过长,水体与空气接触     

Economic Impact of Double‐Crested Cormorant,Phalacrocorax auritus,Depredation on Channel Catfish,Ictalurus punctatus,Aquaculture in Mississippi,USA

The Yazoo River Basin of Mississippi, USA, supports the largest concentration of hectares devoted to channel catfish, Ictalurus punctatus, aquaculture production in North America. The Yazoo Basin also supports large numbers of resident, wintering and migrating fish‐eating birds, with the Double‐crested Cormorant, Phalacrocorax auritus, implicated as the most serious depredating species. We used data from aerial surveys of numbers and distribution of cormorants in the Yazoo Basin and on commercial catfish ponds during winters (November–April) 2000–2001 and 2003–2004 to refine estimates of regional economic losses due to cormorant depredation. In both periods, the greatest monthly estimates of cormorant foraging occurred from 1 January to 31 March. Losses in terms of biomass, number, and dollar value were greater for foodfish ponds than fingerling ponds. Monthly weighted estimates of catfish consumed were 1775.3 and 1346.6 m.t. over winters 2000–2001 and 2003–2004, respectively. Total estimated losses for foodfish and fingerling ponds in 2000–2001 were $11.56 and $0.48 million, respectively, and in 2003–2004 were $5.22 and $0.40 million, respectively. Maximum dollar loss occurred during March in 2000–2001 and during February in 2003–2004. In this study, the volatility in variable production costs and nominal sales price, and distribution of cormorants on pond types and regionally were key factors in resulting economic loss estimates.     

越冬期间黄颡鱼、大鳍组织器官含脂量变化的研究

通过对嘉陵江北碚江段黄颡鱼，大鳍Hu越冬期间其胃，肠，肝胰脏，肌肉含脂量变化的研究。表明：1．黄颡鱼，大鳍Hu内脏各器官（胃,肠，肝胰脏）含脂量以越立中期为最低，肌肉则相反，表现出越立饥饿期间，该鱼主要利用内脏脂肪作用为主要能量来源而不用大量肌肉脂肪；2，越冬期间，黄颡锺，大鳍Hu内脏各器官（胃，肠，肝胰脏）含脂量与含水量的变化有负相关关系存在。     

生石灰对蟹虾围塘养殖的影响

通过对越冬和非越冬锯缘青蟹、脊尾白虾、弹涂鱼耐生石灰试验,证明青蟹有很强的耐生石灰能力,脊尾白虾有较强的耐生石灰能力。蟹虾围塘养殖在围塘清淤后对越冬青蟹进行生石灰消毒,养殖过程中定期用生石灰泼洒,并与对照塘做对比试验,以及大面积推广应用,结果表明:使用生石灰能使围塘锯缘青蟹、脊尾白虾发病率显著减少,成活率显著提高,生长明显加快,蜕壳时间相对集中,饵料系数明显降低,产量和效益显著提高。生石灰对围塘蟹虾健康生长有很大作用。     

不同交配,越冬方式对河蟹育苗的影响

不同交配、越冬方式对河蟹育苗产量有着显著的影响，三年的生产实践表明：秋季室外土池交配的抱卵率、抱卵量明显高于水泥交配；秋季交配优于春季交配；室外土池自然越冬抱卵卵蟹的胚胎发育优于室外塑料大棚保温越冬的抱卵蟹。适宜的秋，春交配有利于河蟹多苗育苗，延长生长期，增加产量。     

Differential impact of recombinant human activin on LH secretion in male and female common carp during wintering and spawning period

The pituitaries of male and female common carps were subjected to the treatment with recombinant human activin A. Basal LH secretion decreased in females during wintering, but stimulated basal and sGnRH-induced LH secretion during ovulatory period. It stimulated LH secretion in males during wintering, but not during spawning, suggesting sex-specific effect of activin on LH secretion in common carp.     

东、黄渤海带鱼的洄游路线

为了研究带鱼的洄游路线,根据我国10余个主要渔业公司1971、1972、1981和1982年带鱼捕捞统计资料,先绘制带鱼鱼群移动影像图,据此进一步研究东、黄渤海近海带鱼的洄游路线图。结果显示,带鱼越冬场、产卵场和索饵场范围广阔,在空间上具有一定的重叠性。带鱼还有分批越冬、产卵和索饵洄游的特性,不同群体越冬、产卵和索饵洄游在时间上也有一定的重叠性。北方带鱼群体的越冬场主要在32°00'～36°00'N,124°00'～126°00'E黄海暖流水域。3—7月北上进入海州湾、乳山湾、海洋岛和渤海各湾产卵场;8—9月在产卵场外围宽阔水域索饵;9—11月游出渤海,绕过成山头南下,沿禁渔线外侧,沿途分别汇合海州湾、乳山湾及海洋岛的越冬鱼群,到了34°00'N后折向东南,分批于12月到达越冬场。南方带鱼群体越冬场主要位于浙江中南部禁渔线外侧,其次是济州岛西南海域。每年3—4月起,南部越冬的带鱼鱼群大致以每2个月1个纬度的速度向东北方向移动;5—7月,产卵洄游的鱼群到达舟山渔场和长江口渔场产卵;7—8月,产卵后的索饵群体北上黄海南部大沙渔场索饵;9月,索饵群体前锋到达35°00'N禁渔线外侧。10月以后,随着冷空气南下,南部群体带鱼向南越冬洄游,并且在10月回到长江口海域。其中小部分群体游向外海越冬场,大部分群体继续南下回到东海中南部近海的越冬场。台湾暖流和黄海暖流的进退和消长是影响带鱼越冬洄游路线空间和时间变化的主要环境因素。     

Complementary use of natural and artificial wetlands by waterbirds wintering in Doñana,south‐west Spain

• 1. The Doñana wetland complex (SW Spain) holds more wintering waterfowl than any other wetland in Europe.
• 2. This study focused on the use made by 12 common waterbirds (eight ducks and four waders) of the natural seasonal marshes in Doñana National Park (DNP) and the adjacent Veta la Palma (VLP) fish ponds created in the early 1990s. Data used were from aerial and terrestrial surveys collected between October and February during six consecutive winters from 1998/99 to 2003/04. Changes in distribution of each bird taxon were related to changes in the extent of flooded marshes within DNP. Up to 295 000 ducks were counted in VLP during dry periods, and up to 770 000 in DNP when it was flooded.
• 3. The timing and extent of flooding in DNP was highly variable, but there was a consistent pattern in which ducks concentrated in VLP during dry months and winters but redistributed to DNP as more of it was flooded. This refuge effect was also strong for black‐tailed godwits Limosa limosa, but much less so for other waders. Waders feed mainly on invertebrates, and invertebrate biomass in VLP was found to be higher than in DNP. Ducks feed mainly on seeds and plant material, which are more abundant in DNP when flooded.
• 4. When water levels in DNP were stable over the course of a winter, or controlled for in multivariate models, the numbers of ducks at VLP declined over time, probably due to reduced availability of plant foods. In contrast, numbers of waders at VLP were more stable, and their invertebrate prey became more abundant over time, at least in the winter 2003/4.
• 5. In this extremely important wetland complex, the value of natural and artificial wetlands for wintering waterbirds are complementary, providing suitable habitat for different species and for different conditions in a highly variable Mediterranean environment.

Copyright © 2009 John Wiley & Sons, Ltd.     

越冬池溶解氧含量的无线监测与控制系统初步设计

为确保鱼类安全越冬,避免因越冬池缺氧而大量死亡,设计了越冬池溶解氧含量无线监测和增氧机控制系统。该系统运行安全可靠,能够保证鱼类越冬生产的安全性,提高鱼类越冬成活率。     

皱纹盘鲍苗种南方越冬的试验

将在大连地区繁育的平均壳长2.2cm的皱纹盘鲍苗种运至福建省莆田市海域进行海上越冬,使用底面积为350mm×550mm、层间距150mm的7层专用养鲍笼,养殖密度25～80枚/层,饵料为盐渍海带、鲜紫菜、鲜海带苗。经5个月饲育,鲍苗平均壳长增长1.94cm,成活率达94.5%,效果明显优于北方沿海的室内越冬及海上越冬。