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鱼类的体色及其调控 总被引：1，自引：0，他引：1
鱼类在自然环境条件下都有其各自特定的体色.体色不仅是鱼类分类的重要特征,也是其健康状态的衡量标准,同时体色正常与否也直接影响商品鱼的价格.鱼类的体色特征由遗传因素决定,是真皮层下面的各种色素细胞互相配合、互相作用的反映.鱼类色素细胞主要包括黑色素细胞、黄色素细胞、红色素细胞和虹彩细胞.体色变化主要受神经和内分泌调控.鱼类的年龄和性别、食物组成以及生存环境的变化会引起鱼类体色的变化.在人工养殖条件下,往往由于养殖环境剧烈变化、或使用缺乏有效天然色素源的饲料等因素,导致养殖鱼类体色异常,使其失去所特有的天然颜色和光泽.文章综述鱼类体色的形成机理及其变化的影响因素.同时,试图探讨养殖生产中鱼类体色异常的调控方法. 相似文献
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随着水产养殖业的快速发展,各种新发传染病不断暴发流行,其中由野田村病毒引起的传染病,造成大批养殖水生动物死亡,给水产养殖业和生态环境带来了严重威胁。野田村病毒分为α野田村病毒属和β野田村病毒属,以及分类未定的野田村病毒,其中水生动物野田村病毒主要包括鱼类神经坏死病毒、对虾偷死野田村病毒、罗氏沼虾野田村病毒、行动障碍野田村病毒以及贝类神经坏死病毒。一些野田村病毒易感宿主多,如α野田村病毒可感染哺乳动物,虾类野田村病毒可感染鱼类,鱼类野田村病毒又可感染贝类,加之近年来的研究发现一些野田村病毒毒株存在自然重组现象,这对水产养殖业造成了威胁。本文综述了野田村病毒科病毒的分类,水生动物野田村病毒主要种类,以及野田村病毒跨物种传播、病毒重组等研究进展,探讨国内外新发现的水生动物野田村病毒的潜在风险,为有效监测和防控水生动物野田村病毒病提供借鉴。 相似文献
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病毒受体及其研究现状 总被引：3，自引：1，他引：2
受体在宿主细胞与病毒的相互作用中起着极其重要的作用。病毒受体的特性与病毒的宿主范围、组织嗜性有密切关系,是病毒致病性的主要因素之一。病毒受体的研究方法有经典的研究方法,也有现代分子生物学方法。在病毒受体的研究中,通常以分离纯化的细胞膜代替活体细胞来研究病毒受体。通过对病毒与细胞受体相互作用的深入研究,人们已经发现很多受体阻断剂例如植物凝集素和肝素等物质可以阻断病毒与受体的结合,从而为病毒病的防控提供繁殖一些有效的新方法。 相似文献
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Over 1 billion ornamental fish comprising more than 4000 freshwater and 1400 marine species are traded internationally each year, with 8-10 million imported into Australia alone. Compared to other commodities, the pathogens and disease translocation risks associated with this pattern of trade have been poorly documented. The aim of this study was to conduct an appraisal of the effectiveness of risk analysis and quarantine controls as they are applied according to the Sanitary and Phytosanitary (SPS) agreement in Australia. Ornamental fish originate from about 100 countries and hazards are mostly unknown; since 2000 there have been 16-fold fewer scientific publications on ornamental fish disease compared to farmed fish disease, and 470 fewer compared to disease in terrestrial species (cattle). The import quarantine policies of a range of countries were reviewed and classified as stringent or non-stringent based on the levels of pre-border and border controls. Australia has a stringent policy which includes pre-border health certification and a mandatory quarantine period at border of 1-3 weeks in registered quarantine premises supervised by government quarantine staff. Despite these measures there have been many disease incursions as well as establishment of significant exotic viral, bacterial, fungal, protozoal and metazoan pathogens from ornamental fish in farmed native Australian fish and free-living introduced species. Recent examples include Megalocytivirus and Aeromonas salmonicida atypical strain. In 2006, there were 22 species of alien ornamental fish with established breeding populations in waterways in Australia and freshwater plants and molluscs have also been introduced, proving a direct transmission pathway for establishment of pathogens in native fish species. Australia's stringent quarantine policies for imported ornamental fish are based on import risk analysis under the SPS agreement but have not provided an acceptable level of protection (ALOP) consistent with government objectives to prevent introduction of pests and diseases, promote development of future aquaculture industries or maintain biodiversity. It is concluded that the risk analysis process described by the Office International des Epizooties under the SPS agreement cannot be used in a meaningful way for current patterns of ornamental fish trade. Transboundary disease incursions will continue and exotic pathogens will become established in new regions as a result of the ornamental fish trade, and this will be an international phenomenon. Ornamental fish represent a special case in live animal trade where OIE guidelines for risk analysis need to be revised. Alternatively, for countries such as Australia with implied very high ALOP, the number of species traded and the number of sources permitted need to be dramatically reduced to facilitate hazard identification, risk assessment and import quarantine controls. 相似文献
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A protein chip based on surface plasmon resonance imaging (SPRI) was developed for detecting fish iridovirus antibody using a recombinant 50-kDa fragment of major capsid protein (MCP) as an antigen. The diagnostic potential of SPRI for measuring antibodies to the iridovirus MCP was compared with that of a conventional enzyme-linked immunosorbent assay (ELISA) using 40 juvenile rock bream (Oplegnathus fasciatus) serum samples in a nursery. There was a strong positive correlation between the SPRI and ELISA (n = 40, r = 0.939, P < 0.01). Therefore, this recombinant 50-kDa MCP can be used as an antigen for serological studies, and the SPRI, which is a label-free and high-throughput method, is potentially a valuable tool in the serodiagnosis of an iridoviral infection. 相似文献
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Wellehan JF Strik NI Stacy BA Childress AL Jacobson ER Telford SR 《Veterinary microbiology》2008,131(1-2):115-122
A wild peninsula ribbon snake (Thamnophis sauritus sackenii) in Florida was found to have hypochromic erythrocytes containing two different types of inclusions: purple granular inclusions, and pale orange or pink crystalloid inclusions that were round, oval, rectangular, or hexagonal in shape. Transmission electron microscopy revealed hexagonal or pleomorphic, homogenous inclusions and enveloped particles morphologically consistent with a member of the Iridoviridae. Histopathology of the animal revealed necrotizing hepatitis consistent with sepsis. Consensus PCR was used to amplify a 628-bp region of iridoviral DNA-dependent DNA polymerase. Bayesian and maximum likelihood phylogenetic analysis found that this virus was distinct from other known iridoviral genera and species, and may represent a novel genus and species. 相似文献
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Parasites in cultured and feral fish. 总被引：3，自引：0，他引：3
T Scholz 《Veterinary parasitology》1999,84(3-4):317-335
Parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. Despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such 'evergreens' as the ciliate Ichthyophthirius multifiliis, a causative agent of white spot disease, or proliferative kidney disease (PKD), one of the most economically damaging diseases in the rainbow trout industry which causative agent remain enigmatic. Besides long-recognized parasites, other potentially severe pathogens have appeared quite recently such as amphizoic amoebae, causative agents of amoebic gill disease (AGD), the monogenean Gyrodactylus salaris which has destroyed salmon populations in Norway, or sea lice, in particular Lepeophtheirus salmonis that endanger marine salmonids in some areas. Recent spreading of some parasites throughout the world (e.g. the cestode Bothriocephalus acheilognathi) has been facilitated through insufficient veterinary control during import of fish. Control of many important parasitic diseases is still far from being satisfactory and further research is needed. Use of chemotherapy has limitations and new effective, but environmentally safe drugs should be developed. A very promising area of future research seems to be studies on immunity in parasitic infections, use of molecular technology in diagnostics and development of new vaccines against the most pathogenic parasites. 相似文献
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Isabel Jurk 《Veterinary Clinics of North America: Exotic Animal Practice》2002,5(2):243-60, v
Ocular disorders in fish are common and can occur as primary or secondary manifestations of systemic disease. Because most fish are sight feeders, visual impairments usually have fatal consequences for the individual fish and can lead to substantial economic losses for the client. This article encourages practitioners to perform a complete ocular examination as part of routine physical examinations in fish by providing a review of the functional anatomy of the teleostean eye, clinical work-up, ocular examination, ocular diseases, and treatment. 相似文献
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Piscirickettsia salmonis was the first "rickettsia-like" bacteria to be recognized as a pathogenic agent of fish. Since the first reports of piscirickettsiosis emerged from Chile in the late 1980s, Piscirickettsia-like bacteria have been recognized with increasing frequency in a variety of fish species, from both fresh and saltwaters around the world. Although the first reported incidents of Piscirickettsia were in salmonids, Piscirickettsia-like bacteria are now being frequently associated with disease syndromes in non-salmonid fish. Mortalities have occurred in white seabass (Atactoscion noblis), black seabass (Dicentrarchus sp.), tilapia (Oreochromis, Tilapia and Sarotherodon spp.) and blue-eyed plecostomus (Panaque suttoni). Piscirickettsiosis and piscirickettsiosis-like diseases have affected aquaculture productivity, profitability, the species of fish compatible with commercial rearing, and transportation of fish from site to site. Piscirickettsiosis and syndromes caused by similar bacteria are an emerging disease complex that will increasingly inhibit fish production. 相似文献
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《Journal of aquatic animal health》2013,25(2):107-111
Abstract Many effects of diseases on cultured fish are known; they are less clear in wild fish populations. Cultured fish represent captive populations that can be subjected to intense scrutiny with an increasing range of diverse and powerful tools. Disease represents a spectrum from acute mortality to rather benign or inconsequential syndromes, all sharing the common feature of a deviation from the normal structure or function of the host. Understanding these deviations among cultured and wild fish populations and balancing their implications against ecological, economic, and political concerns are challenges for both fish health scientists and fisheries managers. The severity of a given disease is dependent on the interaction of numerous variables of the host, the parasite, and the environment. To understand diseases and their impacts on fish populations, we must know which variables are important, how we measure them, and finally how we assess the results of our measurements. We have perhaps been most successful with variables associated with the pathogen. We often can more easily isolate and scrutinize the pathogen than either the host or the environment. The host variables of importance (for which we lack considerable knowledge) include actions of the immune system in general and specifically the influence of genetics and nutrition on host resistance–susceptibility to disease. Lastly, the contribution of the environment, a nebulous term encompassing everything other than the host and pathogen, is only partly appreciated. While we can measure certain physical and chemical parameters of the environment, we have a poor understanding of the biological–ecological variables that influence host–pathogen interactions. Ultimately, diseases of wild fish must be considered in the context of these complex interactions including numerous physical, chemical, biological, and ecological parameters, which may yet be discovered as integral parts of the aquatic habitat. 相似文献
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中草药防治寄生性鱼病的研究进展 总被引：3，自引：0，他引：3
通过查阅近年来国内有关中草药防治寄生性鱼病的文献,系统的介绍了常见的鱼类寄生虫病,并就中草药对该病害的防治研究与应用进行阐述,以期为寄生性鱼病的防治提供一定的参考。 相似文献
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E M Bernoth 《DTW. Deutsche tier?rztliche Wochenschrift》1990,97(7):285-290
Freshwater fish are of minor importance as vectors of food-borne disease in humans. These diseases can only rarely be traced back to bacterial pathogens. However, there is a number of bacteria with facultative pathogenicity for man, which are part of the natural aquatic environment. Among these bacteria, the motile aeromonads (A. sp.) have become more and more important. A review is presented on A. sp. infections which have been traced back to contact with fish or water. Critical discussion of these cases reveals that the etiological relevance of A. sp. remains unclarified. However, bacteria of this group can be associated with sometimes fatal infections in humans after contact with fish or water. As A. sp. are ubiquitous in water and can survive even in chlorinated tap water, infections are not necessarily restricted to contact with fish. Persons at risk (patients with chronic or malignant diseases, immunocompromised hosts, children, people with frequent contact with water) should be informed about the perceived risks of aeromonads and how to avoid infection. Preventive measures are the wearing of gloves for work which may easily lead to skin abrasions (f. i. gutting of fish) and total abstinence of raw seafood. As their occurrence is independent of the common indicator bacteria, A. sp. are to be included in hygienic monitoring programmes for any water. 相似文献
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Retroviruses comprise a large group of enveloped RNA viruses which have been found in a wide range of vertebrate species including fish. To date a number of fish retrovirus genomes have been partially or completely sequenced. Phylogenetic analysis and genome organization indicate a high diversity of fish retroviruses as well as some unique structural features that have not been found in any other retroviruses. Piscine retroviruses comprise both exogenous and endogenous viruses; most of them are associated with proliferative diseases. Because several of these proliferative diseases have a seasonal trend, they provide an excellent model for studying tumor development and regression. The aim of this work was to review the best-described fish retroviruses. 相似文献