我国内陆水体单殖吸虫的宿主特异性分析

报道我国内陆水体单殖吸虫的宿主特异性的研究。研究表明单殖吸虫有很强的宿主特异性,但不同种类的特异的有很大的判别。从目前已有的记录来看,６０％以上的单殖吸虫中只有１种宿主,约７５％的单殖吸虫的宿主仅为１属,超过９７％的单殖吸虫的宿主在１科之内。没有１种单殖吸虫可生于超过３个料的宿主中,但大钩指环虫可在２３属３３种宿主中寄生。在科和发放持异性水平,以锚首虫科和指环虫科单殖吸虫的特异性较强,三代虫科次之     

异盘并殖吸虫在小鼠体内发育及宿主转换的研究

在我国,引起人体患病的并殖吸虫有卫氏并殖吸虫(Paragonimus westermani)、斯氏狸殖吸虫(Pagumogo-nimus skrjabini)以及尚未引起人们足够重视的异盘交殖吸虫(Paragonimus heterotremus)三种。自从1965年广西那坡县发现异盘并殖吸虫疫源地和一例痰中查见虫卵的患者以来,泰国、老挝等地也分别报告了该虫引起游走性皮下结节与在肺内检获成虫的病例。异盘并殖吸虫对人体的致病性、宿主关系及传播方式等问题,引起了人们的关注。近年来,卫氏并殖吸虫和斯氏狸殖吸虫在非正常宿主体内的发育及宿主转换的研究,日趋深入。研究结果表明,此两种并殖吸虫病均可由转续宿主介导或经宿主转换而传播。异盘并殖吸虫在这方面的研究,迄今尚未涉及。为此,我们以小鼠为动物模型,进行了宿主转换的研究。     

两栖、爬虫、哺乳类寄生单殖吸虫侵袭宿主的策略

单殖吸虫(Monogenea)是低等脊椎动物的体外寄生虫,大多数种类见于鱼类的体表和鳃上,另有一些种类寄生于两栖、爬虫、哺乳类动物。在无尾两栖类单殖吸虫中,有些虫种的幼虫感染蝌蚪的鳃,如多盘虫Polystoma integerrimun;另有一些虫种侵入变态后宿主的肾脏,如原多盘虫Protopolystoma xenopodis和真多盘虫Eupolystoma alluaudi;还有一些虫种侵入宿主的肺部,如美洲伪双睾虫(Pseudodiplorchis americanus)和铲足新双睾虫(Neodiplorchis scaphiopodis),但它们的成虫都寄生在宿主的膀胱内。海龟类爬行动物的单殖吸虫一般寄生于口腔、咽或膀胱中。…     

光照、温度及宿主粘液对河鲈锚首吸虫虫卵孵化的影响

鳜鱼Siniperca chuatsi (Basilewsky)作为一种商品价值很高的鱼类,由于成功地解决了人工繁殖和养殖技术的问题,已成为我国名优水产动物的重要养殖对象。然而,自然条件下的缘鱼常被河妒锚首 吸虫(Ancyrocephalus mogurndae Gussev)寄生,并可引起鳃组织病变1。关于这种吸虫的危害及其引起 鳃组织病理变化的研究尚未见诸报端。在高密度的人工养殖条件下,这种寄生虫在宿主之间的传播速率必定会增加,导致寄生虫种群数量的增加,给宿主带来危害,使级鱼养殖生产遭受损失.据了解,由于这种单殖吸虫的寄生,导致级鱼致病并大批死亡的情况,已在不少养殖场发生且呈发展趋势.研究这种单殖吸虫的种群生态、流行病学以及病原生物学,将有利于正确掌握河妒锚首吸虫对级鱼养殖生产的危害以及研究有效的控制技术和防治方法。本文报道光照、温度及宿主鳃粘液对河妒锚首吸虫虫卵孵化的影响。       

南海扁鮀鲣寄生墨杯虫属单殖吸虫—中国新记录种

2011年11月14日,作者在广东省汕尾进行野生海水鱼类寄生单殖吸虫调查,于扁鮀鲣Auxis thazard thazard(Lacepède,1800)鳃上检获1种分室科单殖吸虫,经研究鉴定属于分室亚科(Capsalinae)墨杯虫属(Caballerocotyla)的群居墨杯虫(C.gregalis)。该种在我国未曾报道,为1中国新记录种,扁鮀鲣为宿主新记录。     

无声囊泛树蛙寄生多盘虫属单殖吸虫一新种

从海南尖峰岭的无声囊泛树蛙Polypedates mutus膀胱内检获多盘虫属Polystoma单殖吸虫1新种,以宿主种名命名为无声囊泛树蛙多盘虫Polystoma mutus sp.nov.。新种以后吸器长相对于虫体全长较小(1.0:7.9～1.0:8.2),锚钩形态,具9根生殖棘等特征而区别于近似种。本种为海南岛多盘虫属单殖吸虫的首次报道。模式标本保存于华南师范大学生命科学学院鱼类寄生虫学研究室。     

横川后殖吸虫中间宿主初步实验观察

横川后殖吸虫中间宿主初步实验观察大连医科大学微生态学研究所大连１１６０２７蔡之宣大连医科大学寄生虫学教研室于小明,崔昱在我国横川后殖吸虫Ｍｅｔａｇｏｎｉｍｕｓｙｏｋｏｇａｗａｉ的第一中间宿主有ＭｅｌａｎｉａｌｉｂｅｒｔｉｎａＭ．ｅｂｅｎｉａｎａ及Ｍ．...     

两种类型卫氏并殖吸虫对猴的寄生适应性的比较研究

自发现卫氏并殖吸虫存在二倍体和三倍体两种类型以来,有关它们对不同动物宿主及人体的致病性及其机理的研究报告已见陆续发表。本文报告两种类型卫氏并殖吸虫对恒河猴和短尾猴的寄生适宜性和致病性的实验研究结果,试图为阐明两型卫氏并殖吸虫的致病机理提供依据。     

澜沧江奇额墨头鱼寄生指环虫属单殖吸虫一新种记述

记述了澜沧江云南省西双版纳景洪流域段(22°00.288'N,100°47.430'E)奇额墨头鱼Garra mirofrontis寄生指环虫属Dactylogyrus单殖吸虫一新种:澜沧江指环虫Dactylogyrus lancangjiangensis sp.nov.。宿主鱼类的自然感染率为68%(19/28)。吸虫平均大小为317μm×101μm。后吸器由1对中央大钩、7对边缘小钩、联结片和副联结片组成;联结片呈一字形,中部狭窄,两端较宽;副联结片呈月牙形;交接器包括交接管和支持器,交接管基部膨大呈球形,后部缢缩形成细管,并盘曲成3~5圈螺旋;支持器呈复杂棒状,交接管端部从中穿过。本种在后吸器和雄性交接器上与指环虫属已记录种存在明显差异,同时鉴于单殖吸虫具有较强的宿主特异性,认为该种是科学上一未记录种。模式标本保存于云南师范大学生命科学学院。     

卫氏并殖吸虫在小鼠体内滞育现象的进一步观察

在卫氏并殖吸虫转续宿主(Paratenic host)的研究中,用小鼠作为动物模型的文献很少,而且均写为用囊蚴感染小鼠后的观察,动物用量也少,因而有所局限。我们在以小鼠等常用实验动物进行卫氏并殖吸虫的宿主转换及转续传播的研究中,分别用囊蚴和滞育童虫感染了大量小鼠,对该虫种在小鼠体内的滞育现象作了进一步观察,报告于下:     

Can host body size explain the parasite species richness in tropical freshwater fishes?

Summary The variability of monogenean gill ectoparasite species richness in 19 West African cyprinid species was analyzed using the following seven predictor variables: host size, number of drainage basins, number of sympatric cyprinid species, host diversity, association with mainland forest, host ecology, and monogenean biological labelling. The size of the host species accounted for 77% of the variation in the number of parasite species per host, and host ecology an additional 8%. Together the effects of host size and host ecology accounted for 85% of the variation in monogenean species richness. This study shows that the deciding factors for explaining monogenean species richness in West African cyprinid fishes are host species size and host ecology. These results were compared with main factors responsible for parasite species richness in fish communities. Other possible explanations of monogenean community structure in west African cyprinids are discussed.     

The underrated importance of predation in transmission ecology of direct lifecycle parasites

Most parasites with complex life cycles exploit trophic webs to pass from host to host in order to develop and, eventually, reproduce. Thus predation constitutes the necessary route for transmission. Conversely, the transmission of parasites that use a single host to develop and reproduce should be, in principle, not particularly affected by host trophic ecology. Here I challenge this view, showing that predation may be relevant also for direct lifecycle parasites. I used a large dataset of fish trophic interactions to investigate if the degree of monogenean species overlap in predators and prey deviated from randomness. I demonstrated that predators and prey often share more monogenean parasite genera than explained by host habitat ecology, geographical distribution and phylogeny. This suggests that predation may play an important role in promoting monogenean host range expansion. In addition, a non‐negligible proportion of considered prey–predator pairs showed a significantly high overlap in their monogenean parasites at the species level. This may indicate a tendency of some monogenean parasites to evolve transmission strategies targeted towards host interactions. If this hypothesis is true, these monogenean parasites would be much more vulnerable to co‐extinction than previously thought. Synthesis Predation is not expected to play an important role in the ecology and evolution of simple life cycle parasites. Yet, several predator fish tend to share with their prey more monogenean parasites than one would expect predicted from their geographical distribution, habitat preference, and or phylogenetic relationships. This suggests that some monogenean parasites have evolved transmission strategies more targeted towards host interactions than towards species‐specific traits. If this hypothesis is supported, it would have strong implications on host–parasite evolutionary ecology, primarily, suggesting the existence of peculiar situations where some parasites have evolved high specialized host finding behaviors to expand their host range.     

A nested parasite species subset pattern in tropical fish: host as major determinant of parasite infracommunity structure

The number of monogenean gill parasite species associated with fish hosts of different sizes is evaluated for 35 host individuals of the West African cyprinid Labeo coubie. The length of host individuals explains 86% of the total variation in monogenean species richness among individuals. Larger hosts harbour more species than smaller ones. The existence of a hierarchical association of parasite species in individuals of L. coubie is demonstrated. Monogenean infracommunities on larger fish hosts consist of all species found on smaller hosts plus those restricted to the larger size categories, suggesting some degree of compositional persistence among host individuals. The findings provide strong support for an interpretation of the relationship between monogenean parasite species richness and host body size in terms of a nested species subset pattern, thus providing a new record of repetitive structure and predictability for parasite infracommunities of hosts.After 15/01/1995, ORSTOM, BP 165 97323 Cayenne cedex Guyane France     

Interactions between monogenean parasites and their fish hosts

Parasite factors associated with recognition and selection of the host and the mechanisms in the host responsible for acceptance or rejection of the invading organism were evaluated. Sensory structures in parasites are able to detect differences between different fish species and this ability to discern between fishes may be based on both chemical and mechanical stimuli on the host surface. Complex glycoproteins, proteins, carbohydrates and simple molecules attract parasites or modify their behaviour. Furthermore, attachment of the monogenean parasite to a host is dependent on both mechanical structures and chemical factors in the parasite. These systems comprise anterior pads, posterior haptors, gland secretions, and muscular elements. The parasite needs access to appropriate nutrients which can be absorbed and used for reproduction and in this context signals from the host are needed for an optimal physiological response of the parasite. The innate and adaptive immune systems of the host are important elements in this question. Investigations have indicated that innate host factors (complement, lectins, acute phase reactants, macrophages) can bind to monogeneans and elicit severe damage to the parasites. The targets for these hostile products are not only the monogenean tegument, but may involve the gastrodermis and glands. However, the parasite's ability to avoid and even exploit the wide array of immunological elements of the host may be an important player in the dynamic interactions between host and monogenean determining host specificity. Even fish hosts susceptible to a certain parasite show an ability to mount a protective response at post-infection periods. Elevation of the host's production of adaptive and non-adaptive factors following monogenean infections of a certain duration may explain the acquired response.     

Nominal species of the genus Gyrodactylus von Nordmann 1832 (Monogenea: Gyrodactylidae), with a list of principal host species

The total diversity of the monogenean genus Gyrodactylus is evaluated. There are 409 potentially valid species names within the genus, recorded from c. 400 host species. Five species have been placed within Fundulotrema and an additional 51 Gyrodactylus species names represent synonyms, nomina nuda or have been reassigned to other non-viviparous monogenean genera. While the majority of Gyrodactylus species (59%) are recorded from single hosts, some have a much broader broad range.     

Investigating patterns may reveal processes: evolutionary ecology of ectoparasitic monogeneans.

We reviewed several published and ongoing studies concerning monogenean communities. Patterns of species richness, host specificity, community structure and host--parasite coevolutionary interaction were carefully analysed, and hypotheses of evolutionary processes are proposed. The structuring of monogenean communities seems to be related to both ecological and historical constraints. The database supports an absence of intra- and interspecific competition in monogeneans. Species richness seems to be more due to host characteristics than to parasite interactions. Monogeneans seem to specialise on large hosts, leading to greater species richness on those hosts. The morphometric evolution of attachment and copulatory organs support the hypothesis of a reproductive segregation among conspecifics parasitising the same host(s). It also suggests the existence of concurrent adaptive and non-adaptive processes. The general absence of a coevolutionary pattern between host and parasites also suggests the constraints of history without dismissing the influences of ecological factors in the structuring of the communities. More generally, we strengthen the need to study the structure of communities in a phylogenetic context.     

The chemical nature of host hatching factors in the monogenean skin parasites Entobdella soleae and Acanthocotyle lobianchi

Fully-developed eggs of the monogenean Entobdella soleae from the skin of the common sole (Solea solea) hatch when treated with dilute solutions of urea or ammonium chloride in sea water. There is some evidence that arginine may stimulate hatching but the eggs do not respond when treated with sea water solutions containing trimethylamine oxide or glutamine. Sole skin mucus contains sufficient urea to stimulate hatching but insufficient ammonia. Solutions of urea in sea water stimulate hatching in the monogenean parasite Acanthocotyle lobianchi found on ray skin. Sea water solutions containing ammonium chloride and trimethylamine oxide failed to hatch the eggs of A. lobianchi and the eggs were also insensitive to various amino acids made up at concentrations found in host mucus. Experiments with urease confirmed that urea in ray ventral skin mucus is the host hatching factor for A. lobianchi. Skin mucus from the common sole failed to stimulate hatching in A. lobianchi. The role as hatching factors of excretory products in host gill effluent, skin mucus and urine is discussed.     

寄生鳜鱼鳃部河鲈锚首吸虫的摄食特点

本文报道了鳜鱼［Ｓｉｎｉｐｅｒｃａｃｈｕａｔｓｉ（Ｂａｓｉｌｅｗｓｋｙ）］鳃上寄生的河鲈锚首吸虫［Ａｎｃｙｒｏｃｅｐｈａｌｕｓｍｏｇｕｒｎｄａｅ（Ｇｕｓｓｅｖ）］的食物组成及其能量储存的形式。联苯胺—过氧化物酶染色显示河鲈锚首吸虫摄食宿主的血液,过碘酸Ｓｃｈｉｆｆ氏反应显示其也摄食宿主的粘液。尽管在河鲈锚首吸虫的肠腔发现残余的细胞,但这些细胞是否为宿主的鳃组织细胞尚待进一步的研究证实。河鲈锚首吸虫体内储存有大量的脂肪,表明有氧代谢的存在并可能是能量供给的主要形式,尽管在虫体的实质中也有糖原的存在。