池塘蓄水养蛏提高产量的关键技术

池塘蓄水养殖缢蛏是一种高产、高效、优质的养殖模式,具有生长快、养殖周期短、产量高、单位成本低等优点。池塘蓄水养蛏,提高产量的关键是严格掌握并有效地控制水质、饵料、底质三要素。     

池塘蓄水养蛏大规模死亡原因及防治对策

缢蛏是我国“四大养殖贝类”之一,为重要的经济软体动物,是福建省宁德市蕉城区沿海群众池塘与滩涂贝类养殖的主要品种。蕉城区缢蛏养殖历史悠久,过去主要以滩涂养殖为主,90年代以后利用原有虾池进行池塘养殖。由于缢蛏池塘蓄水养殖周期短、投资小、收益大,生产比较稳定,且首次采用人工蓄水养蛏技术。在一定时期内,获得了良好的经济效益并掀起养蛏热潮。目前,蕉城区池塘蓄水养蛏面积达2000公顷,年产量达2．5万吨左右,成为福建省养蛏大县。但近年来,由于诸方面原因的     

提高池塘蓄水养蛏产量的三项关键技术

池塘蓄水养殖缢蛏具有生长快,养殖周期短,产量高,单位成本低等优点,是一种高产、高效、优质的养殖模式,严格掌握并有效地控制水质、饵料、底质三要素,是提高蓄水养蛏产量的关键。     

提高池塘蓄水养蛏产量的三项关键技术

池塘蓄水养殖缢蛏具有生长快,养殖周期短,产量高,单位成本低等优点,是一种高产、高效、优质的养殖模式,严格掌握并有效地控制水质、饵料、底质三要素,是提高蓄水养蛏产量的关键。     

肥水养蛏的技术要点

近年来，闽东沿海地区利用虾池采取人工施肥投料，供给缢蛏饵料生物和养料，进行蓄水精养缢蛏，群众称之为肥水养蛏。肥水养蛏较常规的蓄水养蛏具有生长快，养殖周期短，产量高，产品质量好，效益显著等优点，深受群众的喜爱，较好地得到推广；同时也为虾池综合利用，实现虾池增产增值开辟一条新途径。根据近年生产实践中的观察总结，现将肥水养蛏的主要技术措施介绍如下：一、播种前的准备工作1．场地选择：根据缢蛏的生物学特性和肥水养蛏的要求，选择的池塘要有环沟和一定面积的中央滩，环沟深1米左右，沟宽不低于2米，以便于施肥，对进…     

供饵式缢蛏养殖试验

<正>缢蛏(Sinvnovacula constricta)是我国海产经济贝类及增养殖种。20世纪90年代前以平涂粗养或滩涂蓄水养蛏为主,90年代后逐渐发展为池塘蓄水养蛏或与对虾、梭子蟹、海水鱼类、藻类等混养。养殖方式的改变提高了池塘综合养殖效益。但是传统的蓄水养蛏或混养方式需在养蛏池内直接施肥培饵或投饵,容易出现池水过肥、水质不稳定、底质老     

几种农药清除蓄水养蛏敌害试验

海水池塘蓄水养蛏由于长期蓄水,危害缢蛏生长的敌害生物多,本文作者通过对蓄水养蛏过程中出现的沙蚕等敌害的清除试验,选择出能杀死敌害而对缢蛏无影响或影响小的农药,为蓄水养蛏清除敌害提供参考依据。     

缢蛏池塘养殖大面积死亡原因分析与防治措施

缢蛏Sinonovacula constricta（Lamarek）系瓣鳃纲、异齿亚纲、帘蛤目、灯塔蛤科、缢蛏属,俗名蛏子、青子、竹蚶、海蛏,是我国“四大养殖贝类”之一,是福建省沿海群众池塘与滩涂贝类养殖的主要品种。福建省养蛏历史悠久,过去大多为滩涂养殖。上世纪90年代以后池塘蓄水养蛏在福建省逐渐兴起,由于采用这种方式养殖周期短、投资省、产量稳定、收益大,在全省得到较快的发展。目前福建省池塘蓄水养蛏面积达1万hm^2左右,     

缢蛏与三疣梭子蟹池塘轮养技术

长期以来,闽东沿海池塘主要以培育肥水的方式养殖缢蛏,但在养蛏过程中大量的施肥投料,使过剩的肥料沉积池底,底质逐渐恶化.近年来,池塘养蛏生长慢,高温期发病严重,成活率低,产量不高,效益不明显.沿海群众于2002年开始改池塘缢蛏单养为缢蛏与三疣梭子蟹轮养,效益显著,规模逐年扩大.缢蛏与三疣梭子蟹轮养即养蛏结束后,接着高温期不播种蛏苗,而进行梭子蟹养殖.现将其池塘轮养技术要点介绍如下.     

蛏池套养虾、蟹经验谈

近来，笔者在对我县缢蛏养殖业调查过程中了解，大部分养殖户为增加缢蛏养殖池塘的经济效益，在养殖方式上采取了多种套养措施，有蛏池套养南美白对虾、东方对虾，蛏池套养梭子蟹、锯缘青蟹，蛏池套养东方对虾、锯缘青蟹等。比较少见的是后一种，养殖200亩(四个蛏池)均取得较好的经济效益，亩平均产蛏252．1千克、东方对虾12．4千克、锯缘青蟹35．3千克，亩平均产值3095元，亩平均纯收入超过1500元。现将其主要经验总结如下：     

Fish assemblage associations and thresholds with existing and projected oil and gas development

Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km^?2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks.     

奶牛酮病发病机理研究进展

结合国内外目前研究状况较为详细的综述了奶牛酮病的病因与发病机理,并分析了奶牛酮病发生的生化机制。旨在对临床实践中很好的认识诊断和群体监控奶牛酮病提供较为系统的理论依据,保证奶牛群的高产和稳产,从而创造良好的经济效益。     

添加植酸酶日粮不同磷水平和钙磷比对生长肥育猪血液生化指标和骨骼性能的影响

本试验利用饲养试验方法,研究玉米-豆粕型日粮中添加植酸酶时不同磷水平和钙磷比对生长肥育猪血清指标和骨骼性能的影响。试验选用162头20kg左右的杜长大三元杂交猪进行2×3(磷水平×钙磷比)因子饲养试验,试验分2个阶段进行,前期为生长期体重在20-60kg,后期为肥育期体重为为60-100kg。结果表明:添加植酸酶日粮磷水平对血清磷含量和碱性磷酸酶的活性影响显著(P<0.05);钙磷比对血清钙和血清磷含量的影响显著(P<0.05);添加植酸酶日粮磷水平和钙磷比对生长肥育猪骨骼性能的影响不显著(P>0.05)。在添加植酸酶条件下,降低日粮磷水平不影响猪的正常生长发育。     

Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges

Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs.     

Esophagoscopy and gastroscopy in dogs and cats. Technics and indications

A report is presented of esophagoscopy and gastroscopy in cats and dogs using flexible endoscopes. Following consideration of the basic equipment, an account is given of patient preparation and anesthesia, topography, investigation technique and normal findings. Diagnostic potential, indications and risks involved are discussed.     

Gar biology and culture: status and prospects

Many lepisosteid populations in North America have declined and many are now threatened as a consequence of habitat loss and alteration and commercial and sport overfishing. Over the last two decades, morphological, histological and molecular studies allowed distinguishing between different phases of development and the nutritional condition of larvae. Ontogeny of the digestive enzymes of gar larvae indicated the possibility to feed them artificial feeds since early developmental stages. An in vitro digestibility system to test different feed ingredients has been used. Important characteristics of artificial diets were identified through different feeding experiments. Endocrinological studies showed the feasibility of altering larval development and the digestive capacity of larvae. Cloning of gar growth hormone opened new avenues to enhance growth in the gars. Plasmatic vitellogenin was isolated and purified, to develop a competitive enzyme‐linked immunosorbent assay, which allowed the straightforward separation of males from females to establish appropriate proportions for reproduction and also was used to evaluate hormonal protocols to induce gonad recrudescence and spawning. This review analyzes the biology, ecology and physiology of different gar species as a basis for their domestication, mass production of larvae for repopulation experiments and for the culture of commercial‐size gar.     

加快城乡统筹，推进我国农垦体制创新与经济发展的研究与思考

“十一五”以来,我国农垦加快体制机制改革、结构调整和经济增长方式的转变的步伐,参与市场竞争,努力提升企业和产品竞争力,经济社会事业发展较快,对国家的贡献提升,职工收入、生活质量明显提高和改善,示范引领作用不断增强。本文针对农垦体制机制创新进展滞缓,战略定位与发展方向不明,经济增长方式转变和结构调整缺乏资本、人才、技术的支撑,没有处理好改革、发展、稳定、民生的关系,投资匮乏,发展后劲不足,人才短缺和劳动力素质低下的现状,提出在未来农垦体制机制创新中要特别关注改革方向、目标设定与评估,改革要在现行法律法规的框架内运作,改革时机的选择,处理好改革发展稳定与民生的关系,调整好内部利益分配关系,自觉融入区域经济,与地方协同发展等问题。为了促进农垦的发展,建议国家加大对农垦体制机制创新、现代农业建设、国有农场土地资源的保护、社会保障体系的完善等财政和政策的支持力度。     

川渝地区鸡皮刺螨的流行与综合防治

鸡皮刺螨是鸡的一种体外寄生的节肢动物,流行十分广泛,对养殖业发展有严重影响。为了解鸡皮刺螨的发病情况,对川渝两地的126个鸡场进行流行病学调查,感染率高达71%。同时,介绍了鸡皮刺螨的生活史、危害及防治措施,是防制鸡皮刺螨不可多得的资料。     

Composition and diversity of fish and fish catches in closures and open-access fisheries of Kenya

Abstract  Catch composition, relative abundance and diversity of fish catches in open access and three old fisheries closures were compared and contrasted with previous ecological studies. There was less variation in catch community composition among the fishing grounds than the closures, suggesting that fishing has homogenised catch composition. The trap survey found that some parrotfish [ Leptoscarus vaigiensis (Quoy &Gaimard), Calotomus carolinus (Valenciennes) and Scarus ghobban Forsskål] were relatively more common and that some important predators of macro-invertebrates [ Balistapus undulatus (Mungo Park) and Cheilinus chlorourus (Bloch)] were less common in the fishing grounds than closures. Unexpectedly, and in contrast to visual census results, cumulative number of species in catch surveys was higher in open access than closures sites. This may result from fishers covering more area and habitat or a reduction in the catch of competitively subordinate and rare species by aggressive, early-caught fish that can dominate bait. Comparisons of ecological visual census surveys and fisheries-dependent methods indicated that small differences in catch composition can reflect larger ecological differences and that baiting methods can underestimate biodiversity. Ecological impacts of fishing and large-scale changes in marine ecosystems must be considerable given the many fisheries-dependent assessments report modest changes.     

中国鲟鱼的保护、管理与产业化

1　世界现存鲟鱼的种类和资源鲟鱼是一类起源早、具有重要科学研究价值和极高经济价值的稀有物种 ,多数种类个体大 ,半数种为溯河洄游产卵鱼类。按目前较为公认的分类系统 ,现存鲟鱼类有 2科 6属 2 7个种 ,隶属于硬骨鱼纲、软骨硬鳞总目、鲟形目 (Acipenseriformes) ,其中鲟属有 17个种 ,主要经济种类在其中。它们全部分布于北半球 ,现存 9个自然分布区为 :太平洋东岸、北美大湖地区、大西洋西北部、北美密西西比河流域和墨西哥湾、大西洋东北部、里海地区、西伯利亚及北冰洋流域、黑龙江和日本海、长江和珠江。鲟鱼自然种群资源稀少 ,在过…