太湖翘嘴红鲌的生物学及其增殖问题的探讨

本文从研究翘嘴红鲐的生长、各个时期的食性和繁殖生物学出发，对于翘嘴红鲐在太湖渔业资源中的地位及作用作了比较深入的探讨。作者认为，过去把翘嘴红鲐简单地当作有害于太湖鱼类资源的凶猛鱼类而不加节制地加以捕杀，是造成目前太湖鱼类组成小型化和渔获物经济价值下降的原因之一。因此提出了保护和增殖翘嘴红鲐的主张，并且具体地提出了有关翘嘴红鲐的起捕规格、禁渔期和禁渔区、限制有害渔具、实行人工放流和保护水域环境等一系列建议。     

人工养殖翘嘴红技术

正翘嘴红鲌分类上隶属鲤科、鲌亚科、红鲌属。翘嘴红鲌俗称白条、太湖白鱼,是远近闻名的"太湖三白"之一,翘嘴红鲌个体大、生长快、肉质洁白、肉味细嫩鲜美为鱼中珍品,市场价格较高,是热门的养殖品种之一。目前湖泊和水库的翘嘴红鲌资源日益减少,不能满足市场需要。因此,开展翘嘴红鲌池塘养殖技术试验研究,对于渔业产业结构调整、新品种开发利用、保护鱼类资源都十分有益。1生物学特性翘嘴红鲌属中、上层大型淡水经济鱼类,行动迅猛,善于跳跃,容易受惊,拉网操作时,可"飞"越1m多     

太湖鲌鱼数量变化规律及生态效应分析

通过2003~2005年的食性分析和渔获物组成调查,研究了太湖翘嘴红鲌、蒙古红鲌数量变化的规律及在鱼类群落演替过程的作用。食性分析表明:太湖翘嘴红鲌、蒙古红鲌主要摄食鲚鱼,其次是小型鱼类和虾。其中鲚鱼在翘嘴红鲌、蒙古红鲌消化道的出现率分别为95.24%、59.26%;在翘嘴红鲌食物中的重量组成比例为59.2%±11.4%。渔获量统计表明:1952~1958年鲌鱼平均年产量为406.4±102.5 t、占渔获总量的6.28%±0.85%;1987年达到历史最高产量1 090.8 t、占渔获总量7.65%;1993年后鲌鱼资源在快速减少,由1993年的922.3 t、占6.55%下降到近年的100~160 t、仅占渔获总量的0.4%~0.8%。2004年调查表明,在74 667kg渔获物中,翘嘴红鲌、蒙古红鲌仅占0.0038%。分析历年渔获量变化趋势发现,随着鲌鱼数量的不断减少,鲚鱼和小型其它鱼类均呈相反的快速增加趋势,而银鱼则有大体一致的持续下降趋势。简单相关和偏相关分析发现,鲌鱼-鲚鱼、鲌鱼-小型鱼类渔获量的负相关关系达到显著水平;鲌鱼-银鱼渔获量的正相关关系达到显著水平。研究认为:太湖翘嘴红鲌、蒙古红鲌对鲚鱼和小型鱼类有很强的抑制作用,对银鱼可能有间接促进作用;人为过度捕捞使翘嘴红鲌、蒙古红鲌数量不断减少,从而导致鱼类群落向鲚鱼为绝对优势种、小型鱼类不断增加的方向变化。鲚鱼和小型鱼类主要摄食浮游动物,其快速增加抑制了浮游动物、有利于浮游植物生长,这是太湖蓝藻频繁暴发的生物学因素之一。     

翘嘴红鲌池塘精养技术

翘嘴红鲌俗称白条、太湖白鱼、翘鲐子．属肉食性鱼类．其主要活动于水体的中上层．是长江水系主要优质经济鱼类之一。为了探索翘嘴红鲌池塘精养效果．我们进行了相关试验。现将情况总结如下。     

翘嘴红鲌的生物学特性及养殖技术

翘嘴红鲌 (Ｅｒｙｔｈｒｏｃｕｌｔｅｒｉｌｉｓｈａｅｆｏｒｍｉｓ)在分类上隶属于鲤科、鲌亚科、红鲌属 ,是长江流域的优质经济鱼类之一。与蒙古红鲌相比 ,前者无论是个体大小 ,还是生长速度均超过后者。翘嘴红鲌俗称白条、和顺、太湖白鱼 ,是远近闻名的“太湖三白”之一。该鱼个体大 ,生长快 ,肉质洁白细嫩 ,味道鲜美 ,为鱼中上品 ,鲜食或腌食都十分可口 ,目前在江浙沪市场价格比较高。然而 ,近年来湖泊、水库翘嘴红鲌的天然资源日益减少 ,不能满足市场需要。因此 ,翘嘴红鲌人工养殖的前景看好 ,对翘嘴红鲌开展人工繁殖及池塘养殖技术的…     

翘嘴红鮊及其养殖技术

翘嘴红鲌(Erythroculter ilishaeformis)俗称白条、太湖白鱼、翘鲌子,分类上隶属鲤科、鲌亚科、红鲌属,是长江流域优质经济鱼类之一。由于长期的过度捕捞,其天然资源越来越少,而市场需求量日趋增长。为有效保护和合理开发这一珍贵资源,湖南沅江市近几年进行了翘嘴红鲌的池塘主养、套养和网箱养殖,取得较好的生产效果,同时也积累了一定的技术经验,现总结介绍如下,供养殖户参考。     

翘嘴红鲌及其养殖技术

翘嘴红鲌(Erythroculter ilishaeformis)俗称白条、太湖白鱼、翘鲌子,分类上隶属鲤科、鲌亚科、红鲌属,是长江流域优质经济鱼类之一.由于长期的过度捕捞,其天然资源越来越少,而市场需求量日趋增长.为有效保护和合理开发这一珍贵资源,湖南沅江市近几年进行了翘嘴红鲌的池塘主养、套养和网箱养殖,取得较好的生产效果,同时也积累了一定的技术经验,现总结介绍如下,供养殖户参考.     

翘嘴红鲌优质高效养殖技术讲座(一) 翘嘴红鲌生物学特性和人工繁殖技术

翘嘴红鲌(Erythroculter ilishaeformis),俗名大白鱼、翘嘴巴、翘壳、白丝、兴凯大白鱼、翘鲌子、鲌刺鱼、翘白、白鱼、噘嘴子浮鲢等,广东地区俗称长江和顺,长江中游俗称翘白、白鱼,长江下游俗称太湖白鱼。隶属鲤科、鲌亚科、鲌属,是鲌属鱼类中个体最大、生长速度最快的种类。翘嘴红鲌为江河优质经济鱼类之一,其肉质洁白、细腻、肉味鲜美。     

翘嘴红鲌人工繁殖和养殖技术

翘嘴红鲌分类上隶属鲤科、鲌亚科、红鲌属。翘嘴红鲌俗称白条、和顺、太湖白鱼,是远近闻名的"太湖三白"之一,其个体大、生长快、肉质洁白、肉味细嫩又鲜美,为鱼中上品。目前湖泊和水库的翘嘴红鲌资源日益减少,不能满足市场需要。因此,开展翘嘴红鲌人工繁殖、池塘养殖技术、网箱养殖技术等的研     

80:20池塘养殖翘嘴红鲌商品鱼技术

翘嘴红鲌,俗称白条、太湖白鱼,属鲤科、鲌亚科、红鲌属,其个体较大,生长速度快,是长江流域的优质经济鱼类.该鱼肉嫩刺少,味道鲜美,是深受广大消费者喜爱的鱼中上品.由于自然资源的锐减,其在市场上供不应求,随着翘嘴红鱼自人工繁育苗种技术的成熟,人工养殖翘嘴红鲌具有广阔的前景.     

长荡湖水生植被动态及其渔业效应的研究

本文根据1983年—1984年调查研究结果分析整理而成。文中论述了长荡湖现有水生植被的种类组成,群落结构,生态分布,沉水植物的生物量及其利用。经过分析比较,发现近30年来,长荡湖水生植被经历了旺盛—衰竭—恢复—旺盛的演替过程,揭示了引起植被变化的各种因素。随着水生植被的动态变化,长荡湖的鱼类种群结构,渔获对象及捕捞工具都相应发生了变化。植被的盛衰同浮游植物和浮游动物、底栖生物的消长丰歉有着密切的关系.本文最后指出了长荡湖水植被的演替趋势和潜在危机,强调了合理利用和定向改造水生植被的重要性,并对今后如何发展我国湖泊渔业提出了建议。     

Does habitat occupancy by lake trout and lake whitefish in large lakes match published thermal habitat envelopes?

Habitat occupancy patterns of lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis) in two large Canadian Shield lakes were modelled based on detections of fish from repeated depth‐stratified surveys over several summers. Lake trout and lake whitefish consistently occupied sites outside traditional thermal envelopes and were not detected at some sites within these ranges. This included the metalimnion and shallow epilimnion for lake trout and lake whitefish in Lake Opeongo. Physical habitat covariates were not important in defining lake trout habitat in both lakes. Physical habitat as represented by the hardness/softness gradient based on acoustic substrate surveys was important for lake whitefish in Lake Opeongo but not in Smoke Lake. In addition, thermal envelopes for lake whitefish differed between the lakes possibly because of differences in substrate slope. The wash zone of lakes, where the thermocline contacts the substrate, appears to be a physical habitat feature for lake whitefish in some lakes. Lake whitefish also exhibited diurnal activity behaviour that was reflected through greater detection rates in the morning versus the afternoon. By accounting for imperfect detection, true estimated overall occupancy of lake trout and lake whitefish increased 0.15–0.30 over naïve occupancy. Thermal habitat envelopes for lake trout and lake whitefish are wider than previously thought. Lake trout occupied a consistent thermal habitat envelope while lake whitefish varied between lakes likely because of lake specific differences in basin morphology and wash zone.     

The large‐scale stocking of young anadromous whitefish (Coregonus lavaretus) and corresponding catches of returning spawners in the River Tornionjoki,northern Baltic Sea

Stocking and fishing effort are two important potentially conflicting factors in fish stock management that require appropriate assessment to ensure a sustainable fishery. In the River Tornionjoki, which discharges into the northern Baltic Sea, a summer‐ascending whitefish, Coregonus lavaretus L., stock has long been a target by traditional dipnet fishing. Enhancement stocking of young whitefish started in the River Tornionjoki in the 1970s after a collapse in catches, with millions of age‐0 whitefish stocked annually in the river, but after about three decades, the stocking rates were considerably reduced. As a result, dipnet catches of whitefish in the Kukkolankoski Rapids rose simultaneously, peaking in the 1980s and 1990s, and then subsequently decreased. There was a significant positive correlation between stocking intensity and catch, both in weight and in numbers, revealing a strong relationship between whitefish releases and dipnet catch. Changes in gillnet fishing effort in the sea affected dipnet catches in weight as well as in mean size of captured whitefish. When the combined effect of stocking and gillnet effort was evaluated, only stocking significantly affected dipnet catches.     

Seasonal and long‐term changes in fishing depth of Lake Constance whitefish

Abstract The ecosystem of Lake Constance in central Europe has undergone profound modifications over the last six decades. Seasonal and inter‐annual changes in the vertical distribution patterns of whitefish were examined and related to changes in biotic and abiotic gradients. Between 1958 and 2007, the average fishing depth in late summer and autumn was related to two factors influencing food supply of whitefish – lake productivity and standing stock biomass. In years with low food supply, whitefish were harvested from greater depths, where temperatures were up to 4 °C lower. The whitefish’s distribution towards colder water might be a bioenergetic optimisation behaviour whereby fish reduce metabolic losses at lower temperatures, or it may result from a reassessment of habitat preference under conditions of limited food supply, according to the ideal free distribution theory.     

The introduced species fishery of Lake Naivasha,Kenya: ecological impact vs socio‐economic benefits

Lake Naivasha is a shallow, freshwater lake in the eastern Rift Valley of Kenya. Its fish community now comprises only introduced species. Oreochromis spirulus niger was stocked in 1925 as a forage fish for the largemouth bass, Micropterus salmoides, introduced in 1929 for sport fishing. Further introductions of tilapiines followed for commercial exploitation. A gillnet fishery opened in 1959, and the annual species catch composition to 2000 was dominated by Oreochromis leucostictus. Following their accidental introduction, carp Cyprinus carpio appeared in catches in 2002; by 2010, it comprised >99% of landings by weight. Carp now provides a sustainable fishery in a lake heavily impacted by anthropogenic stressors, including water abstraction and nutrient enrichment. Oreochromis niloticus was reintroduced in 2011 to reinvigorate tilapia stocks following the collapse of its stocks in the 1990s and early 2000s, and the African catfish Clarias gariepinus is now captured in small but increasing numbers. The current status of the fishery, especially the predominance of carp, presents major management challenges; these are addressed by stakeholder engagement and co‐management. The introductions have artificially created a commercial fishery that provides substantial societal benefits in a semi‐arid region of a developing country with high poverty levels.     

Combining fishery prohibition with stocking of landlocked salmon, Salmo salar L.: an effort to gain bigger yield and individual size

After stocking landlocked salmon, Salmo salar L., in Lake Änättijärvi, all fishing was prohibited for 18 months to provide time for the fish to establish and reach a larger size prior to capture. The potential benefit of the fishery prohibition was severely diminished by emigration of the stocked fish down the watercourse to other lakes. Only 19% of the recaptures of Carlin-tagged individuals came from Lake Änättijärvi. Also, the CPUE of test fishing in Lake Änättijärvi indicated a steep decline in the density of stocked fish during the fishery prohibition period. The mean weight of landlocked salmon in the combined recaptures from Lake Änättijärvi and other lakes downstream was 660 g. When fishing was not prohibited, the corresponding mean weight at recapture was 442 g. It is recommended that landlocked salmon stocking should be carried out in lakes with relatively low fishing pressure.     

以滆湖为例湖泊种植饲料水草的养鱼效果研究

本研究以典型的浅水草型湖泊滆湖为对象,通过对几种水草营养成份的分析,草食性鱼类对这几种水草摄食程度的比较,发现草鱼、团头鲂最喜食的水草为苦草、轮叶黑藻和菹草。为促进这些饲料水草的繁茂,在湖区进行了这三种水草不同方法的种植及合理利用技术的试验。根据所得结果,提出了苦草刈割间隔期以23天为宜;通过割草养鱼试验,提出了蓄草养鱼的配套技术措施,并对滆湖网围养鱼的发展提出建议。     

长江下游浅水湖泊石臼湖鱼类资源现状及变化趋势

根据2012-2013年对石臼湖水质和鱼类资源开展的2次调查数据,研究石臼湖水质、鱼类资源现状及演变趋势。采用水质单因子评价方法、营养状态质量指数,结合经济合作与发展OECO富营养湖泊判断标准,研究石臼湖、姑溪河、塘沟河、清水河的水质和富营养化状况;通过商业捕捞的渔获物调查,收集石臼湖和姑溪河鱼类资源数据,分析河网区鱼类种类组成、渔获物结构等渔业资源现状。结果表明,石臼湖及毗邻水域存在一定程度的水污染,且湖区受水量变化影响低于河流区,总体水质状况符合地表水环境质量Ⅲ~Ⅳ类,为富营养状态。石臼湖分布鱼类110种,2012-2013年共调查到54种;其中,石臼湖38种,固城湖33种,姑溪河51种。石臼湖、固城湖和姑溪河主要经济鱼类(数量和重量均超过1%的种类)分别有13、11和9种。石臼湖鱼类主要以鲤[Cyprinus(Cyprinus)carpio]、鲫(Carassius auratus)、鲇(Silurus asotus)等适应静、缓流生境的鱼类为主,并以歺又鱼(Hemiculter leucisculus)、鲫、棒花鱼(Abbotina rivularis)等小型鱼类或小规格个体鱼类(1 000 g)为主;湖区天然渔业资源呈衰退趋势,由于和长江下游干流相通,姑溪河鱼类种类数高于湖区,但其生物量远低于湖区;渔业资源的分布状况与水质状况无明显相关性,与河湖的连通性有关;受枯水期水量偏少、上游和周边来水污染以及高密度水产养殖的影响,石臼湖水质出现氮、磷和有机污染物超标等问题。宜采取源头控污、限制养殖、渔民转产以及人工增殖等措施,保护石臼湖水质,恢复天然渔业资源。     

兴凯湖鱼类群落结构变化与渔业资源利用

2012年5月-10月,对兴凯湖鱼类及渔业资源利用状况进行了调查,2012年渔产量约为295t,工作渔船209条,期间共统计渔获物1081kg,生物学测定803尾,经鉴定共有鱼类50种。近年来,兴凯湖生态环境的改变导致鱼类种群结构变化,渔获物个体趋向低龄化、小型化,产量持续下降。本研究整理了历史数据并将其与本次调查结果进行对比,分析渔获物组成特征以及渔产量动态变化特点,找出鱼类群落结构的变化趋势,提出了未来兴凯湖渔业资源可持续利用的建议。     

Management and restoration of fish communities in Lake Taihu, China

The economic development of the cities around Lake Taihu, China, has caused both environmental changes and ecological succession. The biodiversity of Lake Taihu has declined since 1970. Migratory fish, including anadromous, catadromous and semi-migratory fish, are either extinct or on the verge of extinction in Lake Taihu. Only lake dwellers persist. Several measures have been taken, such as restocking, closed seasons, sanctuaries for enhancement and even introductions to restore some original fish communities. Although these measures have achieved a certain degree of success, increased fishing activities or over-fishing have offset the benefits obtained. Moreover, cultural eutrophication of the lake and the pollution of the waterways connected with the lake are getting worse. This jeopardizes the remaining economically valuable species in the lake. Measures are required not only to control eutrophication and pollution, and to reduce the intensity of fishing, but also to address the wider biodiversity issues.