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1.
河南省蜉蝣新种记述:昆虫纲:蜉蝣目   总被引:1,自引:0,他引:1  
本文描述了采自河南省伏牛山地区的蜉蝣目3新种,即河南刺翅蜉Centroptilum henanensis sp.nov.长茎锯形蜉Serratella longipennis spn.nov与黑铗细蜉Caenis nigroforcepssp.nov.讨论了它们区别于近似种的特征。  相似文献   

2.
蜉蝣目昆虫染色体制备方法探讨   总被引:3,自引:0,他引:3  
本文对蜉蝣目昆虫染色体制备方法进行了探讨。以蜉蝣稚虫为材料,经秋水仙素水溶液体外培养,采用显微操作技术,结合空气干燥法,可以获得形态良好、分散适中、着色清晰的生殖细胞染色体,为蜉蝣目昆虫细胞遗传学研究提供了一种简便有效的方法。  相似文献   

3.
回顾了世界蜉蝣目化石研究简史,列出已发表的化石种类名录、分布及年代,共40科、124属、218种,其中包括中国的8属13种;描述了不同地质时期主要蜉蝣化石的分类单元和分布地区.简要介绍了蜉蝣分类系统及系统发育、稚虫食性、与其它昆虫的关系和古生态等方面的研究成果.在本文的第2部分,初步分析了目前该类群所存在的一些问题,并对今后的研究工作进行了展望.  相似文献   

4.
记述采自中国香港的蜉蝣目扁蜉科2新种。根据稚虫和成虫的形态特征,详细描述了中国新纪录属康扁蜉属Compsoneuria 1新种:大埔浯康扁蜉Compsoneuria taipokauensis sp.nov.。该新种的成虫标本由稚虫在实验室内饲养而成。根据稚虫形态特征,详细描述了高翔蜉属1新种:箭鬃高翔蜉Epeorus sagittatus sp.nov.。  相似文献   

5.
现存蜉蝣翅基纵脉走向及愈合模式(昆虫纲:蜉蝣目)   总被引:1,自引:0,他引:1  
周长发 《昆虫学报》2007,50(1):51-56
有翅昆虫翅基纵脉的走向及愈合模式在系统发育重建中占有重要地位。然而,现存蜉蝣翅基纵脉的走向及愈合状况在大部分种类变化极大,无法推测其原始状况,只在极少数种类保留有部分可见残迹。中国拟短丝蜉Siphluriscus chinensis的翅基保留有独立的亚前缘脉弓、部分中脉M和肘脉Cu主干以及前中脉MA及径分脉Rs的走向痕迹。据此并结合红斑蜉Ephemera rufomaculata 和大网脉蜉Chromarcys magnifica翅基的相关特征,本文提出了蜉蝣目主要纵脉基部走向及愈合的基本模式,其要点有:中脉主干在基部与径脉主干独自发出后先接近或愈合后又分离、它们各自分成两支后的前中脉及径分脉又先愈合再分离、肘脉始终独立。这种中脉与径脉先接近或愈合后分离的模式非常接近新翅类的情况而与蜻蜓很不相同(在蜻蜓,中脉与肘脉在基部愈合) 。亚前缘脉弓的作用相信是加强了因翅基骨板发达而相互远离的纵脉间的连结作用。这个假说也可以来解释蜻蜓复杂脉相的形成原因。  相似文献   

6.
报道了中国一新纪录属,即大鳃明了 属Torleya Lestage(1917),并详细描述了该属一新种,宽茎大鳃蜉T.grandipennis Zhou,Su et Gui,sp.nov.的形态特征,并将其与近似种作了比较。  相似文献   

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在海南省琼中县、陵水县和乐东县发现埃蜉属一新种,定名为海南埃蜉Ephoronhainanensissp.nov,新种与广泛分布于欧洲、亚洲北部(俄罗斯、蒙古、中国东北)的贞洁多脉蜉Ephoronvirgo(Oliver,1791),相近似,但新种前翅MA脉分支点不与Rs脉第2次分支点位于同一纵线上,而在Rs脉第2次分支点之后;贞洁多脉蜉的前翅MA脉分支点与Rs脉第2次分支点位于同一纵线上。两者有明显的区别。  相似文献   

9.
归鸿  鲁亮 《昆虫学报》1999,42(3):297-299
报道了采自江苏省南京紫金山麓四节蜉属一新种逸仙四节蜉Baetis yixiani sp.nov.(成虫、稚虫),该新种稚虫近似于B. laetificus,主要区别为前者腹部第1~7节有7对鳃,而后者腹部第2~7节只有6对鳃。模式标本保存于南京师范大学生物系。  相似文献   

10.
昆虫界的“四不象”——一新建“螳Xiu目”昆虫简介   总被引:1,自引:0,他引:1  
该文对2002年5月建立的昆虫新目-螳Xiu目Mantophasmatodea作了简单介绍,并建议了该目之中名。该目是昆虫纲中最小的目,目前已知2属3种,分布于非洲。  相似文献   

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Summary We examined how mayfly larvae (Ephemeroptera,Callibaetis montanus) balance the conflicting demands of avoiding both benthic hypoxia and fish predators. Using vertical oxygen and temperature gradients typical of ice-covered lakes, we observed the behavior of mayflies in the presence and absence of fish. In the absence of fish and with adequate oxygen, mayflies spent most of the time on the bottom substrate. As benthic oxygen concentration declined, mayflies increased their activity and moved up in the water column. In the presence of fish and with adequate oxygen, mayflies spent even more time associated with the bottom substrate and reduced their activity levels. As benthic oxygen concentrations declined, mayflies increased their activity and moved up in the water column, but to a lesser extent than when fish were absent. Because of this depression in activity and reluctance to leave the bottom substrate, mayflies endured lower oxygen concentrations in the face of predation threat relative to when fish were absent. Despite this trade-off, benthic hypoxia resulted in increased mortality due to fish predation. Because benthic invertebrates vary in their ability to tolerate hypoxia and in their vulnerability to fish predators, periods of benthic hypoxia could lead to selective predation on some taxa and be an important force structuring benthic invertebrate assemblages.  相似文献   

13.
A video system, consisting of a high-resolution, infrared-sensitive, surveillance television camera, time-date generator, video recorder and high-resolution monitor, was developed for naturalistic observation of the subaquatic activities of larval mayflies. Exemplars were isolated from light, sound and mechanical disturbance, and their burrowing behaviour was recorded for subsequent slow-motion analysis. Larvae of silt-inhabiting Hexagenia limbata were observed to be ploughers that displaced and compacted soft substrate in the excavation of an open tunnel. The head and prothoracic legs had the principal roles in substrate displacement, while the mesothoracic and metathoracic legs drove the body forward. Five stereotyped burrowing cycles were distinguished, although one, termed the Alternate Undercut because of the motions of the prothoracic legs, predominated. Larvae of clay-inhabiting Pentagenia vittigera were observed to chisel and gouge out compacted substrates, also creating an open burrow. Their mandibular tusks were used to dislodge substrate, while the prothoracic legs displaced loosened substrate and widened the opening. The body was driven forward either by strong abdominal flexions or by activity of the mesothoracic and metathoracic legs. Four burrowing cycles were distinguished, two of which, the Tusk Gouge and the Chisel and Sweep, predominated. Differences in proportion and armature of the head and appendages correlated with the different substrate types excavated.  相似文献   

14.
The extant global Ephemeroptera fauna is represented by over 3,000 described species in 42 families and more than 400 genera. The highest generic diversity occurs in the Neotropics, with a correspondingly high species diversity, while the Palaearctic has the lowest generic diversity, but a high species diversity. Such distribution patterns may relate to how long evolutionary processes have been carrying on in isolation in a bioregion. Over an extended period, there may be extinction of species, but evolution of more genera. Dramatic extinction events such as the K-T mass extinction have affected current mayfly diversity and distribution. Climatic history plays an important role in the rate of speciation in an area, with regions which have been climatically stable over long periods having fewer species per genus, when compared to regions subjected to climatic stresses, such as glaciation. A total of 13 families are endemic to specific bioregions, with eight among them being monospecific. Most of these have restricted distributions which may be the result of them being the relict of a previously more diverse, but presently almost completely extinct family, or may be the consequence of vicariance events, resulting from evolution due to long-term isolation. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment  相似文献   

15.
现存被子植物原始类群及其植物地理学研究   总被引:7,自引:0,他引:7  
在吸取各学派对被子植物原始类群界定的基础上,根据八纲系统,提出被子植物原始类群有60科的新见解,并以分子系统学提出的狭义的基部类群32科为对比,进行了植物地理学研究。以科为性状,以Takhtajan 划分的世界植物区系的“区”为OTU,UPGMA分析显示:(1)东亚区确是一个十分特殊的区,它既与北美东、西部(北美大西洋区、马德雷区)有密切关系,但更接近印度支那区;(2)环太平洋的4个地区集中了较多的原始被子植物的科,它们是东亚地区,北美东部和西部地区,部分热带亚洲、澳大利亚东部和西南太平洋岛屿地区,中、南美热带地区。这种分布格局显然和被子植物起源地与扩散以及太平洋的形成历史有关。  相似文献   

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A brief survey is presented on fossil reproductive structures of early Angiosperms from the Lower and mid-Cretaceous and at the same time on the reproductive structures of those extant Angiosperms which resemble most closely these fossils and which seem to be especially primitive also on other grounds: a first group (Degeneriaceae, Himantandraceae, Eupomatiaceae, Austrobaileyaceae) possessing relatively complicated and conspicuous flowers with elaborated inner staminodes, a second group (Chloranthaceae, Trimeniaceae, Amborellaceae) possessing small and relatively simple, inconspicuous flowers with peculiar features in the carpels, and a third group (Winteraceae) possessing flowers with unusual variability in organ number and size. The three groups exhibit a certain diversity in pollination biology, although cantharophily seems to prevail, however different the cantharophily character syndromes may be between the groups. In the extant primitiveMagnoliidae variability occurs on other morphological levels than in the higher advanced Angiosperms. This has to be taken into consideration in evaluations of the systematic relationships of the various groups of theMagnoliidae. Presumably often their relationships are closer than it may appear at first sight. This is also true for the three groups here discussed.  相似文献   

18.
Accurate identification of aquatic species is fundamental to freshwater research. In this paper, we targeted Ephemeroptera, a key taxonomic insect group for biomonitoring of water bodies and present an overview on the efficacy of the DNA barcoding approach to document species identity in the Mediterranean region. We sequenced the mitochondrial cytochrome c oxidase (COI) in 39 nominal species. Sample discrimination and species identification were investigated by evaluating haplotype identity and similarity, intra-/interspecific genetic distances, optimal identification of barcoding gap thresholds, estimates of species monophyly and comparative species matches on available reference libraries. The resolving power of the obtained data was discussed in the light of statistical tools such as Spider R-package and Poisson Tree Processes. High levels of species identification were achieved with all the used methodologies, and the occurrence of cryptic species was suggested. We conclude that DNA barcoding is a powerful tool for taxonomic research in Mediterranean mayflies, with great promise to ameliorate biodiversity inventories of freshwater ecosystems and to provide the necessary accuracy for water quality assessment programs. Our results further indicated we need to upgrade the current regional mayfly diversity knowledge. The development of a Mediterranean reference library could integrate this new information system.  相似文献   

19.
对波纹杂毛虫幼期形态特征作了详细描述;该虫在福建省1a发生2代,以3—4龄幼虫在地被物中越冬;系统观察了各龄幼虫的取食过程并计算了取食量。开展了室内外防治试验。为该虫综合防治提供了科学依据。  相似文献   

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