泥鳅的池塘无公害高产养殖技术

泥鳅又名鳅鱼,鳗鱼鳅,鳛鱼等,在鱼类分类学上属鲤形目,鳅科.泥鳅具有较好的食疗作用和较高药用价值,在我国民间有"天上斑鸠,地上泥鳅"之佳誉,也素有"水中人参"之美称,深受广大消费者的青睐.汉沽区水产技术推广站,自从2000年开始进行泥鳅的池塘高产养殖实验,经过几年的摸索,养殖技术日趋成熟,养殖面积已经从最初的20亩发展到500亩,平均亩产可达3 000 kg,亩效益达到2万元,创造了良好的经济和社会效益.当前,满足国内和国际市场的需求,发展无公害泥鳅养殖,提供更多优质的泥鳅水产品,是当今泥鳅人工养殖业的发展方向,现将泥鳅无公害养殖技术介绍如下.     

有机食品--水产业发展之必然(之一)

[编辑部按]坚持人与自然和谐发展--人类永恒的话题:建立人与自然的和谐关系,促进人类文明的持续、长久的发展,现已受到世界各国政府和人民的高度重视,突出表现在:发展"有机农业"这种新的农业生产模式,在全球大多数国家取得共识,并得到迅速推广.特别是在我国,大力提倡和推广有机农业,对推动农业结构调整和产业升级,增加从业人员的收入,提高食品质量和安全水平,保护人民身体健康,以及加入WTO后应对国外农产品的冲击,规避其他国家的"绿色壁垒",都将起到积极而深远的影响.     

横峰县美蛙养殖业可持续发展的思考

1美蛙养殖现状横峰县位于江西省东北部,是个以低山和丘陵为主的农业县,养殖水面1万余亩,美蛙养殖业发展较早,已经形成了一定的产业化发展基础。横峰县美蛙养殖是1999年开始的,当时苗种都是外地购买,养殖面积6600m2,产量33 t,随着养殖技术的不断成熟和市场的需求量增大,到目前为止全县美蛙养殖面积达2万多m2,产量170 t,实现了养殖面积和产量跳跃式发展。美蛙苗种也做到了自繁自养,年产量达60万只,不仅能供应本县养蛙业的需求,而且可外售部分蛙苗,全县养蛙业实现了“一条龙”式的良性发展模式。此外,随着全县养蛙业的不断发展,在美蛙销售上做…     

鲟鱼加工产品及其开发前景

鲟鱼全身是宝,因此成为药品与营养品的重要原料.但到目前为止,在我国还没有一家集鲟鱼繁殖、养殖、加工一条龙的企业,鲟鱼产品市场潜力很大,销售看好,发展鲟鱼产业化,效益良好,前景十分广阔.基于鲟鱼的产品特点以及我国的消费市场潜力分析,展望了鲟鱼加工产业今后的发展前景.     

金鱼的反季节养殖技术

徐州地区由于气候、地理位置等因素的影响,金鱼生长周期短,养殖高品质金鱼的最大规格仅11～13 cm,为此进行了金鱼的反季节养殖技术试验,将日光温室原理和设施应用到金鱼人工繁殖上来,将繁殖时间提早3个月,年生长天数由180 d提高到280 d,延长了商品鱼的生长时间,提高了商品鱼的规格、亲本越冬的成活率和人工繁殖的受精率、孵化率和正品率,从而提升观赏鱼的品质、档次和观赏价值,获得了显著的社会和经济效益.     

红顶虎头

大菱鲆(Scophthalmas maximus)适应低水温环境,抗逆性强,肉质鲜美,而且生长速度快.自引入我国10年来,在北方沿海地区已迅速发展成为一项特色产业,产生了很好的经济效益和社会效益.但是伴随着养殖范围的扩大和养殖密度的增加,以及品种的退化,大菱鲆的病害问题日趋严重.特别是由盾纤毛虫引起的病害最为严重,盾纤毛虫传染力强,危害性强,一旦发生就会给大菱鲆养殖业造成巨大损失.目前国内报道中治疗盾纤毛虫类病害的有效方法不多,在实际生产中,胡乱用药,用禁药的现象很普遍.因此如何筛选高效、低毒、低残留的无公害药物防治此病迫在眉睫.本文就中草药对盾纤毛虫的治疗效果作了初步研究,供广大养殖户参考.     

浅水塘养鱼也能高产

随着农业产业结构的调整,水产养殖业的发展对促进农村经济发展起到了重要作用.但是受地域空间的限制,部分池塘的养殖空间窄小,而且反复利用,造成池底淤积现象也越来越严重,水体水位过浅(不足2 m),养殖空间变小,养殖环境恶化,养殖效率降低,而要全部改造成深水塘又非一朝一夕能办到.那么,如何使这些浅水池塘发挥作用,以取得较好的生产效益,笔者对周边养殖户多年调查、探索,总结出浅水塘高产的四点体会.     

鉴别亲鱼成熟度的新方法——手摸鉴别法

一般判断鱼类雌雄亲鱼性成熟情况的方法是在该鱼类的繁殖季节,将雌鱼鱼体向上,稍露水面,两侧明显看到卵巢轮廓,用手轻压腹部,柔软富有弹性;雄鱼珠星明显,并有很强的粗糙感,鱼体腹部向上,轻压腹部两侧,有乳白色的浓稠精液流出,遇水迅速散开者为好。这种方法存在的问题是:     

文人雅士说河豚

河豚,是一种肉味极为鲜美的洄游性鱼类,被誉为“百鱼之王“和“鱼中极品“.但河豚体内含有致命的剧毒,品尝河豚这道美味,是要拿宝贵的生命去冒险的,我国民间素有“搏死食河豚“的说法.明代医学家李时珍著的《本草纲目》中,就有关于河豚味美和有毒的记载:“河豚有大毒,味虽珍美,修治失法,食之杀人.“……     

模糊综合评判在地热温室养殖水产决策中的应用

根据特种水产的生活习性,食物结构以及经济效益,利用地热资源,构成养殖水体,在一定的养殖水域面积内,采用合理搭配,立体养殖方法,拟定了三个特种水产养殖方案,应用了模糊综合评判的方法决策,选出其最优方案,并在罗田三里畈地热开发公司实施,收到了良好的经济效益和社会效益.     

氟苯尼考用于水产养殖的安全性

氟苯尼考(florfenicol)，又称氟甲砜霉素，是一种新型广谱高效抗菌药物，自20世纪90年代初开始应用于水产养殖。1990年氟苯尼考首次在日本上市用于治疗黄尾蛳(Seriola lalandei)、真鲷(Pagrosomus major)、银大马哈鱼(Oncorhynchus kisutch)、日本竹笑鱼(Trachurus japonicus)、虹鳟(Oncorhynchus mykiss)、香鱼(Plecoglossus altivelis)、罗非鱼和鳗鱼等的假结核性巴氏杆菌病(pasteurellosis)和链球菌病(streptococcosis)，随后，韩国、挪威、智利、加拿大、英国等分别上市用于治疗专门疾病。中国1999年批准氟苯考尼为国家二类新兽药，在水产养殖上可用于治疗鳗鲡爱德华氏病和赤鳍病。本研究从氟苯尼考抗菌活性与药效学、药代动力学、毒理学、以及药物残留、耐药性等方面探讨其用于水产养殖病害防治的安全性，旨为该药在中国水产养殖中的科学合理应用提供理论参考。     

Scale calcification in the goldfish in vitro: histological and quantitative analysis

The external layer of a teleost fish scale is composed of type I collagen, an amorphous matrix substance and hydroxyapatite crystals. Calcification of this layer can be inhibited in the scale-regenerating process under calcium- and phosphate-deficient (CaDPD) conditions, and can be facilitated by incubation in physiological saline. The aim of this study was to evaluate this model of calcification using histological and quantitative analysis in order to promote further understanding of the mechanism of calcification in fish scales. We found that the external layer of the scales produced under CaDPD conditions contained more densely aligned collagen fibrils with a small amount of the amorphous matrix substance. The CaDPD scale contained only one-third of the amount of calcium and phosphate present in the control fish. After 4 hours of incubation, a two- to threefold increase in calcium content and a 1.5-fold increase in phosphate content were observed. Calcification proceeded in the external layer, and mineral deposits grew only in the electron-dense matrix substance. We conclude that this model would be suitable for studying the early process of fish scale calcification that occurs in the noncollagenous substance. The electron-dense substance may contain key molecules that promote calcification.     

lncRNA在水产动物中的研究进展

长链非编码RNA(long non-coding RNA, lncRNA)是一类全长超过200个核苷酸的RNA,其转录本缺少开放阅读框和保守密码子,无编码能力。lncRNA能够与RNA、DNA或蛋白质相互作用来介导靶基因的调控,可以在转录水平、转录后水平和表观遗传水平发挥作用。大量研究表明,lncRNA在生殖、胚胎发育、性别分化、免疫和代谢等方面起着关键作用。近年来,关于lncRNA在水产动物上的研究已取得一定成果,但是国内外尚缺乏对其进行全面总结的报道。鉴于此,本文主要对lncRNA的定义及分类、生物学特性、作用机制及在水产动物中的研究进展等方面进行综述,并对其在水产动物中的研究前景进行了展望,以期为以后深入开展lncRNA在水产动物上的功能研究提供参考。     

Nutrient load estimation in the waste of Nile tilapia Oreochromis niloticus (L.) reared in cages in tropical climate conditions

We sought to estimate the nutrient load in the waste released into aquatic environments based on the feeding of Nile tilapia (Oreochromis niloticus, L.) reared in cages that were installed in artificial reservoirs. For the calculation, an analysis of the chemical composition of commercial feeds intended for this species in their various stages of production was conducted (N = 130). We combined this information with a meta‐analysis of published data from commercial producers in Brazil about expected feed intake, feed conversion and other animal production indices, and body composition. With these data, it was possible to estimate the load. We estimated that 18% of the feed given to the animals is not consumed and is lost in the aquatic environment. The calculated average digestibility was 71.97% for the organic matter in the diet, 84.06% for protein and 54.40% for phosphorus. The estimated nutrient deposition efficiency, with respect to what was actually consumed by the tilapia, was 26.39% for organic matter, 43.25% for protein and 34.07% for phosphorus. The total nutrient load in the waste per tonne of biomass of produced tilapias was estimated to be 1040.63 kg of organic matter, 44.95 kg of nitrogen and 14.26 kg of phosphorus, representing 78%, 65% and 72% of the respective nutrient amounts supplied by the feed. The information obtained in this study serves as a reference for predicting the potential impact of tilapia farming in reservoirs and to establish scientific parameters for the planning of this activity.     

Parental care in response to natural variation in nest predation pressure in six sunfish (Centrarchidae: Teleostei) species

Abstract – Parental care is an important, energetically costly component of the life history of many fishes. Despite this importance, little is known about how different species of fish vary parental care in response to natural nest predator burdens. In this study, underwater videography was used to quantify parental care activity of six species of syntopic nesting male centrarchid fishes in Lake Opinicon, Ontario, in response to natural predators. This approach was used to test the hypothesis that as offspring develop from eggs to wrigglers, parental care activity should decrease or remain static for fish guarding nests with low predator burden and increase for those with high predator burden, reflecting different external risks. Principal components analysis (PCA) was used to derive common aeration and nest defence variables. Aeration and predator defence activity of the fish varied extensively among species. Parental care behaviours indicative of defence and vigilance (e.g., turning, departures, time away from nest, displays) tended to be highest for species that had the most predation attempts, although this was not entirely consistent. There was also a positive relationship between the defence PCA metric and attempted predation. Defence did not vary with stage of offspring development, although interactions between defence and developmental stage were noted for several species. A trade‐off between aeration and defence was not observed. In fact, species that provide high levels of aeration also simultaneously provide high levels of defence. Stage‐specific patterns of defence in this study were less apparent than those documented by studies using responses to staged predator intrusions making it unclear as to the extent that fish were responding to the level of the risk to offspring than to the value of the brood. Therefore, combined use of observational and experimental assessments of parental care investment may be most appropriate for refining current theoretical paradigms.     

原位杂交技术在水产动物育种与疾病诊断中的应用

原位杂交技术作为分子杂交的基本原理和免疫组织化学两者相结合的一项技术,有很高的应用价值,其中地高辛标记物凭借其系统安全、方便、省时,敏感性和质量控制优于生物素标记和放射性物质标记技术,被广大研究者认可。本文重点介绍了地高辛原位杂交的原理,概括了其在水产动物育种与疾病诊断中的应用现状。     

Epitheliocystis in fish

Epitheliocystis is a condition affecting the gills and skin of fish, which has been reported from more than 50 freshwater and marine species. It is caused by intracellular Gram-negative bacteria. Mortalities have been associated with epitheliocystis infections in cultured fish. This review provides an update of our current understanding of this condition, including characterization of the pathogen using immunohistochemical and molecular studies. In most fish species the epitheliocystis agent was negative to an antibody specific for chlamydial genus-specific lipopolysaccharide antigen. Recently, four epitheliocystis agents from four different fish species have been characterized using molecular analysis. While they all belong to the order Chlamydiales, in a lineage separate from the Chlamydiaceae, they are distinct organisms and similarity analysis showed that they had highest similarity values with other chlamydia-like bacteria isolated from various sources, including humans or pig. This confirms the high diversity and host specificity of the pathogen. Further molecular analysis should result in an increased understanding of this condition. To date the pathogen has not been cultured, making experimental studies difficult. High stocking densities, presence of nutrients, season, temperature and fish age have been identified as potential risk factors for the manifestation of this condition.     

Economic analysis of finfish mariculture operations in Spain

Abstract

This paper analyses the factors determining economic success in finfish mariculture in Spain. With this objective in mind, it models the critical economic variables of this industry; in particular, those related to sales and the learning curve. The proposed theoretical model is applied empirically to companies located in Spain, in order to quantify the effects and to determine the differences that could explain the keys to a company's success or failure.     

江苏省河蟹产业发展研究

江苏省是我国河蟹生产大省,河蟹产业对江苏国民经济发展和农民增收具有重要现实意义。本文重点分析了江苏省河蟹产业经营环境、经济效益和发展能力的概况。通过对河蟹产业现状分析,认为江苏河蟹产业发展还存在诸如缺乏组织与规划、加工水平低及市场不规范等问题,并分析其原因有多元投入与产业结构不合理、技术落后和市场障碍等,最后针对性地提出产业发展政策建议。