鱼类体色调控的基本机制

正养殖鱼类的体色是评价其商品价值的重要指标。在水产养殖过程中,鱼种、水质、管理、饲料等条件的变化均会导致养殖鱼类体色异常,从而降低商品鱼的价值。本文就近年来国内外学者对鱼类体色调控的相关研究进行综述,以期提高对鱼类体色调控基本机制的理解,从而确保养殖     

营养因素对鱼类体色变化的影响

一、鱼类体色变化的机理1.鱼类的色素细胞。鱼类的体色之所以如此丰富,是由于皮肤中具有无数的色素细胞的缘故。色素细胞也分布于神经和血管周围以及体腔膜上。鱼类基本色素细胞有四种。(1)黑色素细胞(melanophore):星状,周围又很多突起,细胞本身含有棕色的、黑色的或灰色的色素     

养殖武昌鱼体色与鳞片黑色素细胞初步观察

水产养殖，尤其是使用配合饲料养殖的淡水鱼经常会发生鱼体体色的变化，这是困扰淡水养殖和水产配合饲料生产的主要问题之一。发生体色变化的鱼类以前主要是无鳞鱼，如黄鳝、塘鲺、黄桑鱼、斑点叉尾鲴、长吻鲍等。目前发现在有鳞鱼类，如武昌鱼、草鱼、鲤鱼等中也经常发生体色变化。体色变化的主要特征是颜色变浅（变白），同时，在体色变化时体表粘液减少或没有了粘液，体表有一定程度的出血，在一些地方将这种变化称为“鱼体发毛”。目前针对养殖生产中出现这类问题的研究报告不多，     

着色剂在水产养殖中的研究与应用

<正>随着我国水产养殖业的迅速崛起,人工养殖水产品的品质问题越来越受到人们关注,其中色泽是影响其商品价格和观赏价值的重要因素。水产动物呈现出的斑斓色彩,在很大程度上受类胡萝卜素的影响,而水产动物自身不能合成类胡萝卜素,必须从食物中摄取。水产动物日粮的主要原料含类胡萝卜素很少,而现代高密度集约化养殖条件下,人工养殖的水产品体色往往缺乏天然水产品所具有的健康色泽,从而使其商品价值大打折扣。因此,在饲料中添加着色剂,对养殖鱼类的体色进行调控,已成为现代水产养殖业的重要技术之一。     

营养素对鱼类体色的影响

体色是影响鱼价格和价值的重要因子之一，影响鱼类体色的因素主要有遗传因素、神经内分泌系统、营养素以及养殖环境等因素。文章就营养素对鱼类体色影响作一简述。     

鱼类体色形成及其营养调控的研究进展

文章阐述了国内外鱼类体色相关研究进展,着重综述了鱼类体色形成的生物学基础、鱼类体色相关基因以及鱼类体色的营养调控,为养殖生产中改善鱼类体色提供了理论依据。     

全植物蛋白饲料对胡子鲶体色的影响

人丁养殖条件下,鱼类的体色问题屡见不鲜（冷向军等,2006）。养殖胡子鲶（Clarias fuscus）对体色要求较高（唐精等,2007）,近年来,常出现一些体色问题,比如：鱼体发黑,变白,上色不均匀等等。最典型的体色异常,俗称“沙皮”化,表现为鱼体着色异常,鱼背、腹部均通体金黄色,并布满黑色细点,     

改善养殖鱼虾体色研究进展

<正> 改善养殖鱼虾类体色问题是目前世界各国水生动物营养学家研究的一个重要课题。近些年来,国外在这一领域的研究取得了一些进展,我国还少有这方面的报道。为今后国内开展这一领域研究提供参考,笔者重点就国外在这方面的研究成果作些介绍。 1.鱼虾体色的成因鱼虾的体色是由色素细胞构成的。色素细胞内含有不同种类的色素物质,根据呈色的不同,色素细胞分类如下:     

池塘养鱼浮头的原因及防治

在池塘养鱼中,鱼类浮头是一种较为常见的现象,特别在春、夏两个季节.由于午后阳光充足、气温上升较高,鱼类采食活动加强,新陈代谢较旺盛,耗氧量随之加大,因而养殖的鱼类极易出现浮头.鱼类浮头后会引起贫血、体色变淡、生长缓慢、呼吸困难.一旦产生浮头,轻则影响鱼的生长,重则造成鱼大面积死亡,严重影响到养殖户的经济效益.本文笔者结合实际养殖经验,总结出导致鱼类浮头的几个主要因素及应对措施.     

水产品增色剂

水产品增色剂西南农业大学水产系林仕梅罗莉叶无土随着现代水产养殖业的发展，由于大量使用人工配合饲料，养殖周期缩短，导致某些养殖鱼类的体色变淡（如鲑鱼、鳟鱼、罗非鱼、真鲷、对虾），无法与天然捕捞的鱼虾的色泽相比，影响商品价格。此外，观赏鱼的体色也被人们所...     

Disease and destiny-mystery and mastery

When early people made their appearance, zoonotic infectious diseases were already waiting, but epidemic diseases did not appear in human history until people began to live in large numbers under conditions of close contact, mainly during the last 10,000 years. Disease has decimated urban populations, conquered armies, and disrupted society. The focus here is on (1) the plague of Athens and the Black Death; (2) smallpox, influenza, and rabies; (3) avian influenza prion diseases, and foot & mouth disease; and (4) emerging and re-emerging diseases. All have veterinary public health associations. In Athens, Greece, in 430 BC, when the Spartans ravaged the countryside, hordes crowded into Athens so that orderly movements, space in which to live, and adequate supplies of food became impossible. Crowding of any population fosters disease transmission; chaos and disorder enhance it all the more. Out of northern Egypt came a terrible plague from across the Mediterranean Sea. The identity of the plague of Athens remains unsure, but the well-considered conclusion is Rift Valley Fever, a mosquito borne, viral zoonosis. The Black Death, also called the Plague, raged in Asia for centuries. In 1347, the Black Death was brought by a ship out of Asia to Sicily. The scenes of devastation were repeated throughout Europe, with 90% or more of the people dying in city after city. Influenza, too, has been a cause of periodic human epidemics, but the great pandemic of influenza occurred in the last months of World War I. In the years of highest occurrence, more than half the world's population became clinically infected. If veterinary public health had been born earlier, it could have led to elucidating the epidemiology of influenza and the plagues of Athens, Europe, and Asia. In turn, smallpox had also caused continual tragedy. In 1796, Edward Jenner began to harvest pustules of cowpox from children or infected cows and inject them into susceptible children. In 1980, the World Health Organization declared that smallpox had been eliminated from the world. Rabies, though, still strikes terror. A number of animal diseases, broadly termed emerging and re-emerging diseases, need surveillance because they have the potential to impact human health. From late in 2003 to 2007, the highly pathogenic H5N1 influenza virus in poultry infected at least 121 people and caused 62 deaths in four countries. The prion diseases, too, all have very high numbers in concentrated contacts. To control these diseases, veterinary public health is essential, with diagnosis, epidemiological surveillance, clinical manifestations, and prevention as primary measures.     

Foot and mouth disease and bluetongue: differences and similarities

On 26th of july 2007 a new case of bluetongue was notified in the Netherlands and on 2nd of august 2007 foot-and-mouth disease was diagnosed in Surrey, England, which raised the threat of having both infections simultaniously in one area. Bluetongue and foot-and-mouth disease have a different pathogenesis, but symptoms may resemble each other at a later stage of infection. The pathogenesis and possible clinical symptoms of both infections are discussed and illustrated with pictures.     

德国荷兰畜禽产品质量安全交流与启示

2018年岁末,笔者有幸赴德国和荷兰,就畜产品质量安全控制及检测技术等进行了短期交流,收获颇丰,现具体介绍如下。一、交流情况德国面积35.73万平方千米,人口约8175.2万,是欧盟人口最多的国家,农业发达,机械化程度很高。德国的畜牧业以猪、牛、羊和禽类为主,畜牧业产值占农业生产总值的61%。德国虽然农业比重很小,但却是有机农业运动最早的发起国,也是目前世界上有机农产品生产与消费大国。     

奶牛肢蹄病及其防治

简介常见奶牛肢蹄病种类及其症状,从日粮营养、运动场地面结构、环境卫生、饲养管理、遗传育种、疾病管理等方面简析奶牛肢蹄病的病因,并提出相应的预防措施。     

畜禽物种多样性及其保护和利用

文章就我国畜禽物种多样性资源的现状、保护和利用等方面进行阐述,为生态脆弱的喀斯特地区畜牧业可持续发展提供参考。     

马的咽气癖及其防制措施研究进展

在动物的异常行为中以刻板行为最为常见,而咽气癖又是马最常见的口部刻板行为之一。作者就咽气癖在生理方面和心智方面对马体产生的影响、行为基础、诱因的研究进展及常见的防治措施进行综述。     

国内外蛋氨酸与赖氨酸市场分析与展望

近几年,世界饲用添加剂市场增长较快,预计今后将进一步增长,据世界粮农组织(FAO)首领会议的倡议,到2015年,将使世界营养不良的人口削减一半,其间,肉制品将会以每年2％的速度增长,特别是加快猪肉和禽肉增长。这将促进世界添加剂,尤其是蛋氨酸和赖氨酸需求量的增加。     

牛羊焦虫病诊断与防治技术

近几年来,辽宁省牛羊饲养业迅速发展,焦虫病的危害越来越明显,已成为危害牛羊的主要疾病之一。为了提高牛羊焦虫病的防治水平,保证我省牛羊饲养业的健康发展,笔者在参阅文献和同行们诊疗经验的基础上,结合自己的治疗实践,详细阐述了我省牛羊焦虫病近几年的流行特点和诊断防治方法。