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1.
Hox基因家族在调控动物早期胚胎发育、组织和器官生长起重要作用,因此这类基因家族被广泛应用到物种进化和发育调控的研究中。为了探究Hox基因在团头鲂中分布,进化及表达调控作用,同时为了探究Hox基因与团头鲂肌间刺发育的关系,研究基于团头鲂全基因组数据,结合生物信息学分析方法对其Hox基因家族进行鉴定、染色体分布、系统进化和表达模式分析。结果显示,在团头鲂基因组中共鉴定出49个Hox基因,根据系统进化分析分为5个亚类;其中49个Hox基因不均匀的分布在5条染色体上,并分为7个基因连锁群（HoxAa、HoxAb、HoxBa、HoxBb、HoxCa、HoxCb和HoxDa）;表达模式分析结果表明,团头鲂Hox基因家族成员具有不同的表达模式;团头鲂和斑马鱼所有Hox基因在肌肉中的表达水平存在显著差异。此外,团头鲂不同发育阶段及不同组织转录组结果显示,HoxA基因群集中,HoxA2a、HoxA3a在幼鱼阶段高表达,其他基因在肌肉、肌间刺及结缔组织中表达量低甚至不表达;HoxB基因群集中,HoxB9a、HoxB3a、HoxB8a、HoxB1b、HoxB5a、HoxB5b在幼鱼阶段高表达;HoxB7a、HoxB10a、HoxB9a在成鱼肌肉、结缔组织及肌间刺中高表达;HoxC基因群集中,HoxC3a、HoxC4a在幼鱼阶段高表达,HoxC3a、HoxC8a在成鱼的3个组织都有表达;HoxD基因群集中,HoxD9a、HoxD10a和HoxD11a在胚胎S2期表达量较高。研究表明,Hox基因在团头鲂早期胚胎时期和肌间刺的形成中有表达,提示团头鲂肌间刺的形成可能受Hox基因家族调控。 相似文献
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Fishing effort is a function of many (continuous) variables which fishers can manipulate. However, when catch and fishing effort data are analysed using a generalized linear model, individual types of fishing effort usually enter as a composite quantity. But not all quantities can be combined into a composite quantity. Use of such data this way generally leads to a loss of information and incurs a model bias. In this paper, I analyse catch and effort data for the blue swimmer crab off South Australia by a direct use of individual types of fishing effort to extract a relative index of biomass, and use the concept of homogeneous functions to present some of the results. I also give formulae for choosing a combination of different types of fishing effort to effect a specified level of catch in both absolute and relative terms. Assuming that catch follows an independent gamma, normal, negative binomial, or Poisson distribution, fitting of a generalized linear model with a log-link function to the commercial catch and effort data suggests that: (1) the exploitable biomass remained relatively constant from 1 July 1983 to 30 June 1996; (2) the relative instantaneous rate of fishing mortality of a particular sex and age (if gear selectivity was constant over time) slightly increased over time; (3) a 1% increase in the number of days fished gave about 0.85% increase in catch whereas a 1% increase in the number of people on a boat led to only about a 0.45% increase in catch. This implies that use of a composite measure of fishing effort such as boat days and man days when analysing catch and effort data is inappropriate for this fishery. Although a generalized linear model may be a reasonable first-order approximation, catch and effort data are best interpreted through a process model. 相似文献
3.
Jianfeng Tong Yoshinori Miyamoto Keiichi Uchida Toyoki Sasakura Jun Han 《Fisheries Science》2014,80(6):1159-1167
In order to monitor the fish volume entrapped over time in a set net in real time, a new remote fish finder system based on a mobile network was developed and tested. This system was designed with a client/server architecture including an echo sounder terminal, a web server, and some end user display terminals, which allowed fishermen to monitor the fishing state of a set net via any display device. In addition, in order to transfer the echo data smoothly via a mobile network, a fish echo extraction method based on image processing and a data organization structure were proposed, which can significantly reduce the data volume for transmission, supply sufficient information to reconstruct the high resolution echogram at the user terminals, and calculate the positional and morphometric parameters of fish echoes. Furthermore, a semiautomatic data recording method for use with a database was proposed to manage the extracted fish echo data and the fishing records. The functions and capabilities of the new system were demonstrated by a sea trial. 相似文献
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D. EVENBERG P. de GRAAFF B. LUGTENBERG W. B. Van MUISWINKEL 《Journal of fish diseases》1988,11(4):337-350
Abstract The development and applicability of a dose-controlled experimental infection with atypical Aeromonas salmonicida in carp is described. The proliferation and clinical manifestations of experimentally induced carp erythrodermatitis mimicked a natural infection. An in-vivo assay was used to evaluate the lethal properties of cell-free culture supernatants and a simple serum-free growth medium was devised for maintaining the virulence of the challenge strain. Depending on the inoculation dose, a sublethal (chronic) to a lethal (acute) infection could be induced, and a dose-response relation was observed between A. salmonicida inoculum size and carp mortality. The dose-controlled experimental infection was used as a challenge test for laboratory evaluation of the efficacy of potential vaccine candidates. The vaccine candidates tested, a cell envelope preparation, purified lipopolysaccharide and purified A-layer (ACE) protein showed no protection or only a feeble one at the best, while formalinized whole cells showed a consistent but only moderate protection. In contrast, when concentrated, detoxified culture supernatant was used, the carp were protected against a subsequent lethal challenge. These observations indicate that immunity against A. salmonicida extracellular products is of prime importance. 相似文献
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《Fisheries Research》2007,87(2-3):153-158
Gulland's [Gulland, J.A., 1965. Estimation of mortality rates. Annex to Arctic Fisheries Working Group Report (meeting in Hamburg, January 1965). ICES, C.M. 1965, Doc. No. 3 (mimeographed)] virtual population analysis (VPA) is commonly used for studying the dynamics of harvested fish populations. However, it necessitates the solving of a nonlinear equation for the instantaneous rate of fishing mortality of the fish in a population. Pope [Pope, J.G., 1972. An investigation of the accuracy of Virtual Population Analysis using cohort analysis. ICNAF Res. Bull. 9, 65–74. Also available in D.H. Cushing (ed.) (1983), Key Papers on Fish Populations, p. 291–301, IRL Press, Oxford, 405 p.] eliminated this necessity in his cohort analysis by approximating its underlying age- and time-dependent population model. His approximation has since become one of the most commonly used age- and time-dependent fish population models in fisheries science. However, some of its properties are not well understood. For example, many assert that it describes the dynamics of a fish population, from which the catch of fish is taken instantaneously in the middle of the year. Such an assertion has never been proven, nor has its implied instantaneous rate of fishing mortality of the fish of a particular age at a particular time been examined, nor has its implied catch equation been derived from a general catch equation. In this paper, we prove this assertion, examine its implied instantaneous rate of fishing mortality of the fish of a particular age at a particular time, derive its implied catch equation from a general catch equation, and comment on how to structure an age- and time-dependent population model to ensure its internal consistency. This work shows that Gulland's (1965) virtual population analysis and Pope's (1972) cohort analysis lie at the opposite end of a continuous spectrum as a general model for a seasonally occurring fishery; Pope's (1972) approximation implies an infinitely large instantaneous rate of fishing mortality of the fish of a particular age at a particular time in a fishing season of zero length; and its implied catch equation has an undefined instantaneous rate of fishing mortality of the fish in a population, but a well-defined cumulative instantaneous rate of fishing mortality of the fish in the population. This work also highlights a need for a more careful treatment of the times of start and end of a fishing season in fish population models. 相似文献
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The development of a pathological condition in the distal intestine of Atlantic salmon, Salmo salar L., induced by dietary soybean meal, was studied in a 6-week feeding experiment. The fully developed condition, as observed after 3 weeks on the experimental diets, was characterized by: (1) a shortening of heights of the mucosal foldings; (2) a loss of the normal supranuclear vacuolization of the absorptive cells in the intestinal epithelium; (3) a widening of the central stroma within the mucosal foldings, with increased amounts of connective tissue; and (4) a profound infiltration of inflammatory cells in the lamina propria. The first signs of morphological changes were observed after 2 days on a diet containing a solvent extracted soybean meal, and within 7 days, all the above mentioned signs were observed. When the fish were subsequently transferred to a control diet, the mucosal folds were rebuilt from the base, resulting in an apparently functional epithelium after 3 weeks. Starved fish also exhibited characteristic changes of the mucosa, including a finely granular cytoplasm replacing the supranuclear vacuoles seen in the epithelial cells of normal fish. In addition, a pattern of irregularly spaced indentations developed in the epithelium of the simple folds. The condition induced by dietary soybean meal was classified as a no n-infectious subacute enteritis, and a pathogenesis involving immunological mechanisms is suggested. 相似文献
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胡子鲇脑型芳香化酶基因全长cDNA克隆及表达 总被引：1，自引：0，他引：1
采用RT-PCR和RACE法,克隆了胡子鲇(Clarias fuscus)脑型芳香化酶基因Cyp19a1b,应用荧光实时定量PCR检测其在前脑、下丘脑、脑垂体、肝、精巢和卵巢6种组织,以及性腺分化前后(出膜后12～30 d)全鱼中的mRNA表达。结果表明,Cyp19a1b cDNA全长2 347 bp,5′端非编码区219 bp,3′端[不包括poly(A)]596 bp,开放阅读框(ORF)1 503 bp,编码500个氨基酸,推测其编码蛋白质分子量为56.388 kD。序列分析及分子系统进化树结果表明,胡子鲇Cyp19a1b氨基酸序列与非洲鲇(Clarias gariepinus)Cyp19a1b同源性最高,达95.6%;与南方大口鲇(Silurusmeridionalis)、黄颡鱼(Pelteobagrus fulvidraco)、斑马鱼(Danio rerio)、斑点叉尾(Ictalurus punctatus)、赤点石斑鱼(Epinephelus akaara)、鲤(Cyprinus carpio)、鲫(Carassius auratus)及稀有鲫(Gobiocypris rarus)Cyp19a1b同源性达75%以上,但与上述鱼类的性腺型芳香化酶基因(Cyp19a1a)同源性低于62%,表明其为脑型芳香化酶,同源性分析结果与根据传统形态学和生化特征分类的结果相一致。荧光实时定量PCR结果显示,Cyp19a1b在胡子鲇上述组织中均有表达,其中下丘脑中表达量最高,肝和精巢最低,在脑部的表达存在明显的性别差异(P<0.05)。此外,在胡子鲇性腺分化前(出膜后12 d)Cyp19a1b即开始表达,但分化前后表达量无显著性差异(P>0.05)。结果暗示Cyp19a1b可能不是引起胡子鲇性腺分化的直接因素,但其可能通过"下丘脑垂体性腺轴"对性腺分化过程产生间接影响。 相似文献
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Infectious salmon anaemia (ISA) is an economically important disease in New Brunswick, Canada. Current regulatory control involves detection of ISAv in broodstock, hatcheries and marine sites through a surveillance program. Prior to recent assessments of operating characteristics of diagnostic tests, the efficiency of this surveillance program was difficult to evaluate. In order to determine the optimal testing strategies for various phases of production, a cost-effectiveness analysis was done for different strategies including single testing and multiple testing with results interpreted in series or in parallel. The lowest cost testing strategy, which would achieve a group-level sensitivity (GSe) of 95% and a group-level specificity (GSp) of 95%, was determined for each production phase. Our analyses showed that the most cost-effective testing strategy depended on the production phase. If sampling is to be carried out in a freshwater facility, then broodstock should be tested by VI alone, while pre-smolts should be tested with IFAT and VI used in series. For fish reared in saltwater, parallel interpretation of results from VI and RT-PCR, or testing with VI alone, are appropriate testing strategies for broodstock. For market-fish, PCR alone is a good screening option. If one assumes the prevalence of ISAv in moribund fish is at least 50%, then a maximum of 5 fish (at a cut-point of 1 positive fish to designate a cage as positive) need to be tested at a cost of $220. If one desired to have a perfect GSp (i.e. no false positive cage designations), serial testing with IFAT and VI is a better option. However, for this strategy a maximum of 9 fish (at a cut-point of 1) need to be tested at a cost of $472. 相似文献
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采用RT-PCR和cDNA末端快速扩增技术(rapid amplification of cDNA ends,RACE),首次克隆了西伯利亚鲟(Acipenser baerii)的CXCR7a和CXCR7b基因的全长cDNA。CXCR7a的cDNA全长为2 325 bp(登录号为:JQ034508),包括207 bp的5'端非翻译区(UTR)、可编码362个氨基酸的1 086 bp的开放阅读框(ORF)及包括poly(A)尾巴在内的大小为1 032 bp的3'端非翻译区(UTR);CXCR7b的cDNA全长为2 423 bp(登录号为:JQ034509),包括209 bp的5'端非翻译区(UTR)、可编码370个氨基酸的1 110 bp的开放阅读框(ORF)及包括poly(A)尾巴在内的大小为1 104 bp的3'端非翻译区(UTR),并对它们编码的蛋白质序列的分子特征进行了分析。氨基酸序列相似性(similarity)分析表明,CXCR7a与人(Homo sapiens)、小鼠(Mus musculus)、非洲爪蟾(Xenopus laevis)、斑马鱼(Danio rerio)的CXCR7相似性分别为82.6%、81.4%、80.9%、81.0%;CXCR7b与人、小鼠、非洲爪蟾、斑马鱼的CXCR7相似性分别为82.9%、82.3%、80.8%、82.5%;西伯利亚鲟CXCR7a与其CXCR7b的相似性最高为96.5%。系统进化树分析显示,西伯利亚鲟与斑马鱼聚为一簇,两栖类聚为一簇,其它高等脊椎动物再进行聚类。对CXCR7a和CXCR7b在各发育时期胚胎及仔鱼的表达状况分别进行定性分析表明,CXCR7a在除卵裂期、囊胚期的胚胎外,其在原肠胚中期至出膜1 d的仔鱼的各时期中均具有表达,CXCR7b在卵裂期至出膜1 d的仔鱼的各时期中均具有表达。另外,从基因组DNA水平上表明CXCR7a和CXCR7b来自不同的基因拷贝。这些结果为进一步研究CXCR7在西伯利亚鲟侧线系统发育中的作用提供了新的基础资料。 相似文献
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A novel multiplex RT‐qPCR method based on dual‐labelled probes suitable for typing all known genotypes of viral haemorrhagic septicaemia virus 
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下载免费PDF全文 D Vázquez C López‐Vázquez H F Skall S S Mikkelsen N J Olesen C P Dopazo 《Journal of fish diseases》2016,39(4):467-482
Viral haemorrhagic septicaemia (VHS) is a notifiable fish disease, whose causative agent is a rhabdovirus isolated from a wide range of fish species, not only in fresh but also in marine and brackish waters. Phylogenetic studies have identified four major genotypes, with a strong geographical relationship. In this study, we have designed and validated a new procedure – named binary multiplex RT‐qPCR (bmRT‐qPCR) – for simultaneous detection and typing of all four genotypes of VHSV by real‐time RT‐PCR based on dual‐labelled probes and composed by two multiplex systems designed for European and American/Asiatic isolates, respectively, using a combination of three different fluorophores. The specificity of the procedure was assessed by including a panel of 81 VHSV isolates covering all known genotypes and subtypes of the virus, and tissue material from experimentally infected rainbow trout, resulting in a correct detection and typing of all strains. The analytical sensitivity was evaluated in a comparative assay with titration in cell culture, observing that both methods provided similar limits of detection. The proposed method can be a powerful tool for epidemiological analysis of VHSV by genotyping unknown samples within a few hours. 相似文献
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Prior to marketing, ornamental tropical fish are currently sorted, graded and counted manually; a process that is labor intensive, stressful to fish and inaccurate. Manipulation of fish movements at our will is a key element in the development of a device for automatically sorting, grading and counting fish by a computer vision system, and the present study is one step towards the development of such a fish-friendly sorting device. The positive phototactic and rheotactic innate responses of guppies (Poecilia reticulata) were exploited to induce them to swim through transparent pipes or narrow channels, to render them ready for inspection by a computer vision system. Water flow direction and velocity, water level, and illumination were effective in inducing fish to move from one container into the other via a narrow transparent pipe. It was attempted to separate guppies moving in groups into individually spaced fish, by introducing an obstacle into a narrow channel or narrowing the transparent pipe. 相似文献
13.
Di Jin Hauke Kite-Powell Porter Hoagland 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):369-387
ABSTRACT We develop a framework for risk assessment in open-ocean aquaculture. The framework consists of three components: a firm-level investment-production model simulates a specific grow-out project and estimates the project's benefit-cost values, a second model calculates the risk premium for a risk-averse investor, and a third model quantifies the option value for a risk-neutral investor. We show that under uncertainty, the traditional NPV rule for making an investment should be modified. We illustrate our models using a case study of open-ocean aquaculture of Atlantic cod (Gadus morhua) in New England. 相似文献
14.
R. I. Muetzelfeldt 《Aquaculture Research》1979,10(1):33-42
The use of simulation models in fisheries management is introduced with the particular aim of encouraging fisheries managers to participate in providing data for or constructing such models. Management models are useful both as a training tool for future managers and as a decision-making tool. The close connection between verbal statements about how a system works and the corresponding computer statements is illustrated by a simple example. The main flows of information associated with a simulation model for management are illustrated, and it is shown that fisheries managers could provide much of the information needed. Finally, an example is given of a management model used as a teaching game, illustrating the components that such models can include and the range of management decisions available for achieving a particular objective. This model is based on a reservoir which can be stocked with two species of trout; the reservoir is to be managed for maximum profit, with revenue coming from people engaging in three recreational activities - angling, sailing and boating. 相似文献
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The objective of this study was to determine whether exposure of rainbow trout (Oncorhynchus mykiss) to water containing a stressed trout or skin extract from stressed and non-stressed trout would elicit a stress response in conspecifics. Juvenile rainbow trout were exposed for 1 hour to water containing a stressed fish, homogenized skin extracts from a non-stressed fish, skin extract from a stressed fish and water with none of these factors. The stress response was measured over a 24-h period (1, 6, 12, 24 h after exposure). Plasma cortisol levels increased at 12 h in fish exposed to water from a stressed fish and skin extract from a stressed fish. Plasma glucose and hepatic hsp70 levels were not affected by treatments. The results suggest that rainbow trout elicit a stress response when exposed to stress-related alarm cues released from conspecifics. 相似文献
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为探究张网捕捞作业对凤鲚幼鱼的损害性,根据2017年5—10月杭州湾北部张网渔业资源调查数据,利用全长分析、幼鱼密度和质量占比等方法,对张网渔获中凤鲚幼鱼的生物学特征及幼鱼密度的变化进行了研究分析。结果表明,5—10月各月份张网渔获物中均有凤鲚幼鱼出现,6月份凤鲚幼鱼的平均全长达到最大值112.8 mm,8月份最小,仅为64.7 mm;平均体质量则是10月份最大,达4.4 g,8月份最小,仅1.7 g。5月份凤鲚幼鱼质量密度最高,达到493.1 g/kg,8月份最低,仅为70.3 g/kg;凤鲚幼鱼的数量密度则是7月份最高,为225 ind/kg,6月份最低,为63 ind/kg。渔获中凤鲚幼鱼质量占比5月份最高,为49.3%,8月份最低,仅7.0%;9月份渔获中凤鲚幼鱼数量占比最高,为21.0%,6月份最低,仅为5.3%。研究结果表明,5月和7月杭州湾北部张网对凤鲚幼鱼的损害程度最高。为保护凤鲚幼鱼资源,除调整禁渔期以外,建议组织开展张网网目尺寸试验,研究不同网目尺寸对凤鲚幼鱼释放的效果。 相似文献
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In the ampulla roof of the wave-like extending horse rectum the muscular coat is only weakly developed as a deltoid-shaped tunica muscularis area, thus forming a place of minor resistance. With regard to the degree of development of the muscular coat a rectal ampulla with a stable form and strong muscles can be distinguished from an ampulla with a labile form and weak muscles. The rupture of the intestinal wall in this region in the case of rupture-experiments as well as the frequent occurrence of diverticula reveals this area as being a place of minor resistance which requires extreme caution during rectal examination. The forensic judgement of a rectal perforation has to be based on detailed pathoanatomical investigations. If the rules of veterinary art had been neglected, the proof of blamelessness for the investigator is being out of consideration. If all rules of veterinary art, however, had fully been observed during rectal exploration, the proof of blamelessness for the investigator is very difficult to be obtained, when a perforation or a rupture has resulted. Only if the rupture is located in the dorsal part of the rectum, there exists the possibility, that it is a spontaneous one, if anatomical conditions, thickness of the muscular coat or the presence of diverticula do support this. 相似文献
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Abstract. Using a panel of special stains employed in human histopathology and immunohistology, the authors diagnosed a tumour from the common gray snapper, Lutjanus griseus (L.), as a myoma, Only a few such tumours have been previously reported from fishes. Gray snapper are readily available and may provide a model for basic studies on this, as well as other, types of tumour. 相似文献