麻痹性贝毒对海洋贝类的影响及加速贝毒净化的研究进展

麻痹性贝毒 (ＰａｒａｌｙｔｉｃＳｈｅｌｌｆｉｓｈＰｏｉｓｏｎ ,ＰＳＰ)是目前世界上分布最广 ,发生频率最高的一种贝毒。它是由ＳＴＸ及其衍生物组成的一类赤潮生物毒素 ,主要来源于能形成赤潮的有毒甲藻。这些甲藻大多隶属于三个属 (Ａｌｅｘａｎｄｒｉｕｍ ,Ｐｙｒｏ ｄｉｎｉｕｍ ,Ｇｙｍｎｏｄｉｕｍ) [1] 。ＰＳＰ毒素目前已知有二十多种 ,其基本结构是四氢嘌呤环 ,根据Ｒ4基团的不同可以分为四类。其中氨甲酰类毒素的毒性最强。那些基本的中毒症状很可能是由它们所引起的。Ｎ -磺氨甲酰类毒素经常存在于肇事的甲藻或贝类中。但由…     

我国海产贝类体中的麻痹性毒素及其来源

在目前已知的海洋藻类毒素中麻痹性毒素（Ｐａｒａｌｙｔｉｃ　Ｓｈｅｌｌｆｉｓｈ Ｐｏｉｓｏｎ,ＰＳＰ）是毒害事件发上频率最高、对人类影响最为严重的一类毒素。文献记载最早发生该类中毒事件的地区,主要是在欧洲和北美的一些海域［１、２］。据不完全统计,在我国因食用染毒贝类引起的中毒事件有几十起,主要发生在东海和南海海域。因此,贝类麻痹性毒素的含量状况和上市贝类的质量是消费者极为关注的问题,同时也是有关海域渔业可持续发展的保证条件之一。为维护和发展贝类养殖业,保证海产品的质量和促进海产品的出口贸易等,深入…     

我国麻痹性贝毒的研究现状

贝类毒素是海洋藻类产生的天然产物,能引发赤潮的海洋藻类有260多种,其中有70多种能产生毒素。由于许多有毒的藻类,被鱼、虾、贝类等海洋生物摄食,其毒素在这些生物体内蓄积,这类毒素称为贝毒,人们食用染毒的贝类可发生中毒,根据中毒症状可分为5类:①麻痹性贝毒(Par-alytic She     

贝毒素的研究现状及产生源探究

海洋中有毒藻类的爆发性增殖或通过在鱼、虾、贝类等海洋生物体内的蓄积会产生一些有毒的活性高分子化合物即海洋生物毒素(marine toxins)，其中，目前危害较大的是贝毒素。贝毒危害具有突发性和广泛性，由于其毒性大、反应快、无适宜解毒剂，给防治带来了许多困难，因此，开展贝毒研究对确保水产品及人类生命财产安全具有重要意义。     

不同温度对微小亚历山大藻生长和藻毒力的影响

<正>水体中的藻类是麻痹性贝毒的主要来源,现已知海洋中有13种单细胞的甲藻类可产生麻痹性贝毒。目前在我国海区已经发现的产毒甲藻主要有3种:塔玛亚历山大藻(Akexandrium tamarense)、微小亚历山大藻(Alezandrium minudum)、链状亚历山大藻(Alexandrium acatenella)。微小亚历山大藻在我国台湾沿海较常见。因此,有必要针对我国沿海的微小     

轮虫强化培养的研究进展

轮虫是海水鱼虾类苗种生产中的重要开口饵料。目前使用的轮虫主要有Ｂｒａｃｈｉｏｎｕｓｐｌｉｃａｔｉｌｉｓ(Ｌ型 )和Ｂ .ｒｏｔｕｎｄｃｆｏｒｍｉｓ (Ｓ型 )两种。由于海产小球藻等单细胞藻类的繁殖速度小于轮虫的摄食量 ,在大规模轮虫培养中单胞藻不能满足需要 ,制约了轮虫的生产。用酵母和含高度不饱和脂肪酸 (ＨＵＦＡ)的人工饵料是替代单胞藻最常用的办法〔1、2〕,但其必需脂肪酸 (ＥＦＡ)缺乏或不足 ,用作轮虫的饵料前需进行ＥＦＡ的强化〔3〕。目前 ,轮虫培养在ＥＦＡ强化、替代饵料、高密度培养、冷冻藻保存利用和休眠卵利用等…     

江苏沿海贝类育苗中单胞藻培养的实用技术

正单胞藻,即单细胞藻类,又称微藻,俗称藻类水,是贝类生长发育过程中主要的饵料,为贝类幼体和稚贝提供了生长所必需的丰富营养。常用作贝类饵料的有金藻门(Chrysophyta)的湛江等鞭金藻(Isochrysis zhanjiangensis)、3011(Isocrydid galbana)、3012(Pavlova riridis galbana)、绿色巴夫藻(Pavlova viridis),绿藻门(Chlorophyta)的扁藻(Platymonas sp.)、     

中国沿海贝类腹泻性贝毒的特征分析

<正>腹泻性贝毒是由有毒赤潮藻类鳍藻属(Dinophysis)和原甲藻属(Prorocentrum)中部分藻种所产生的热稳定的脂溶性多环醚类生物活性物质,主要成分为软海绵酸及其衍生物[1]。该毒素可在贝类等滤食性动物体内富集,通过食物链传递至人类,引起腹泻性中毒,危害食用者健康。腹泻性贝毒在全球沿岸海域均有分布,是世界范围内最具威胁的赤潮藻毒素之一。     

黄渤海贝毒机理及产毒藻类的研究现状

贝类毒素即赤潮藻毒素,贝类通过滤食有毒微藻、细菌等,经过生物累积和放大转化为有机毒素,即贝毒[1]。海洋贝毒主要分为麻痹性贝毒、腹泻性贝毒、神经性贝毒、记忆缺失性贝毒、西加鱼毒素[2-5],此外还有部分溶血毒素。其中麻痹性贝毒是目前分布最广,对人类影响最为严重的一种贝类毒素[6-9]。     

毒贝和贝毒

现存的软体动物约有11万5千种。其巾海洋贝类约有10万1千种，淡水贝类约有1万4千种。它们绝大多数无毒或可供食用，仅少数种类因含有毒素或毒液能使人类中毒，这些具有毒性的贝类称为有毒贝类。据调查，有毒贝类约有80多种，主要分布于海洋中。贝毒对人体健康有不同程度的危害，因而造成社会影响，在一定程度上阻碍了贝类的利用和贝类养殖生产的进一步发展。早在十七世纪，贝毒问题在欧洲就作为医学上的问题进行研究。     

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.     

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.     

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.     

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.     

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。     

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。     

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。     

温度与盐度对老年低额蚤和蚤状蚤生长及生殖的影响_

温度与盐度对老年低额蚤和蚤状蚤生长及生殖的影响王丹丽，李明云，杨天勇，胡章（宁波大学，３１５０１０）关键词老年低额　，蚤状　，温度，盐度，生长，生殖ＥＦＦＥＣＴＳＯＦＴＥＭＰＥＲＡＴＵＲＥＡＮＤＳＡＬＩＮＩＴＹＯＮＧＲＯＷＴＨＡＮＤＲＥＰＲＯＤＵＣＴ...     

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.