倒刺鲃两极虫的宿主新记录及其分子系统学研究  

NEW HOST RECORD AND MOLECULAR PHYLOGENY OF MYXIDIUM SPINIBARBA CHEN ET AL.,2020

作　　者：向瑶 张金叶 赵元莙 XIANG Yao;ZHANG Jin-Ye;ZHAO Yuan-Jun(Chongqing Key Laboratory of Animal Biology,College of Life Sciences,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学生命科学学院,动物生物学重庆市重点实验室,重庆401331

出　　处：《水生生物学报》2021年第6期1316-1322,共7页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31970409和31672280);重庆市自然科学基金(cstc2014jcyjA00006);重庆市教委科学技术研究项目(KJ1400515)资助。

摘　　要：为弄清倒刺鲃两极虫(Myxidium spinibarba)的宿主多样性和胭脂鱼(Myxocyprinus asiaticus)寄生黏孢子虫的种类组成,研究基于形态和分子数据,比较分析了寄生于不同宿主的倒刺鲃两极虫的形态学和形态计量学特征及分子系统发育关系。结果显示:寄生于胭脂鱼和中华倒刺鲃的倒刺鲃两极虫株系在形态学和形态计量学上未出现显著性差异,18S rDNA序列相似度为99.9%-100.0%,遗传距离为0.000-0.001,符合种内变异;寄生于不同宿主倒刺鲃两极虫的株系在系统发育树中嵌合聚支,且寄生于胭脂鱼的倒刺鲃两极虫株系先分化。以上结果表明:研究中两株系与倒刺鲃两极虫为同一物种,但在分子水平已经出现分化;这是首次在胭脂鱼中检获到黏孢子虫,胭脂鱼是倒刺鲃两极虫的新宿主。Myxosporeans are microscopic and simple in morphology,mainly parasitize in fish.Some species can cause host disease even lead to death.Among them,the species of the family Myxidiidae Thélohan,1892 exhibit the broadest range of hosts among all myxosporeans.They are typically coelozoic(rarely histozoic)parasites of marine and freshwater fishes(poikilothermal animals),and a few species are found in another poikilothermal animals(amphibians and reptiles)and homothermal animals(birds and mammals).The genus Myxidium Bütschli,1882 with 230 described species,currently includes the most known species in the family Myxidiidae.The members of the genus Myxidium exhibit the following characteristics:their myxospores are spindle-shaped,straight,crescent,or even sigmoid with somewhat pointed ends;two pyriform polar capsules are located at both ends of the myxospores;the shell valves are smooth or striated;and the suture line bisects the myxospores.Myxidium spinibarba Chen et al.,2020 was first collected and described from the gall bladder of Spinibarbus sinensis Bleeker,1871.Present study reported M.spinibarba again from Myxocyprinus asiaticus Bleeker,1864.Myxocyprinus asiaticus belongs to the family Catostomidaeis,in which only one species has been reported from China.Myxocyprinus asiaticus is a kind of omnivorous benthic fish with important ornamental and edible value.To improve higher economic benefits,M.asiaticus and other fishes with different diets and habitat preferences are often mixed feeding.However,polyculture creates conditions for material exchanges between M.asiaticus and other fishes,and,it also enhances the transmission of parasites or pathogens.To study the host diversity for M.spinibarba and the species composition of myxosporean from M.asiaticus,we analyzed the morphometry characteristics and phylogenetic relationships of M.spinibarba from different hosts based on the morphological and molecular data.Myxosporeans were isolated and photographed from the gallbladder of different M.asiaticus in the same batch.

关 键 词：倒刺鲃两极虫 胭脂鱼 宿主新记录 分子系统学 18S rDNA 

分 类 号：S941.51[农业科学—水产养殖]