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1.
Ricefishes of the genus Oryzias occur commonly in the fresh and brackish waters in coastal lowlands ranging from India across Southeast Asia and on to Japan. Among the three species of Oryzias recorded from peninsular India, two widespread species, O. carnaticus and O. dancena, have previously been reported from Sri Lanka based on museum specimens derived from a few scattered localities. However, members of the genus are widespread in the coastal lowlands of Sri Lanka, a continental island separated from India by the shallow Palk Strait. Although recent molecular phylogenies of Adrianichthyidae represent near‐complete taxon representation, they lack samples from Sri Lanka. Here, based on sampling at 13 locations representative of the entire geographic and climatic regions of the island''s coastal lowlands, we investigate for the first time the molecular phylogenetic relationships and phylogeography of Sri Lankan Oryzias based on one nuclear and two mitochondrial markers. Sri Lankan Oryzias comprise two distinct non‐sister lineages within the javanicus species group. One of these is represented by samples exclusively from the northern parts of the island; it is recognized as O. dancena. This lineage is recovered as the sister group to the remaining species in the javanicus group. The second lineage represents a species that is widespread across the island''s coastal lowlands. It is recovered as the sister group of O. javanicus and is identified as O. cf. carnaticus. Ancestral‐range estimates suggest two independent colonizations of Indian subcontinent and Sri Lanka by widespread ancestral species of Oryzias during two discrete temporal windows: late Miocene and Plio‐Pleistocene. No phylogeographic structure is apparent in Sri Lankan Oryzias, suggesting that there are no strong barriers to gene flow and dispersal along the coastal floodplains, as is the case also for other generalist freshwater fishes in the island.  相似文献   

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A survey of morphological characters is carried out for Stapeliopsis . The information obtained from this is combined with molecular data from the plastid trn L-F DNA region and ITS1 of the nuclear encoded 18S−26S rRNA cistron, to obtain a hypothesis of the evolutionary relationships among the species. It is shown that Stapeliopsis is monophyletic in a combined molecular and morphological analysis. Stapeliopsis is sister to a clade containing Huernia , Orbea and Tromotriche . The species of Stapeliopsis group into two clades. One contains S. khamiesbergensis , S. neronis and S. urniflora , and this is highly supported. The remaining species fall into an unsupported clade in which S. exasperata is sister to the others. The genera Hermanschwartzia Plowes and Neopectinaria Plowes are rejected. It is shown that a synapomorphy for Stapeliopsis is the laterally flattened inner corona-lobes, which touch the anthers only at their bases. Eight species of Stapeliopsis are recognized, with no subgeneric divisions.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 125–155.  相似文献   

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Parthenocissus (the Virginia creeper genus, Vitaceae) consists of 13 species and shows a disjunct distribution between Asia and North America. We investigated the inflorescence structure, calyx morphology, appendages on the inner side of petals, leaf epidermis, pollen and seed characters throughout the genus. A combined phylogenetic analysis with 27 morphological and 4137 molecular characters was conducted and the result was largely congruent with that of the previous molecular work, but with higher resolution. The combined analysis identified two clades corresponding to the Asian and North American taxa. Parthenocissus feddei was resolved as closely related to the clade containing P. cuspidifera, P. heterophylla and P. semicordata. The four species share synapomorphies of having conspicuously raised veinlets, an obscurely five‐ (to eight‐) lobed calyx, appendages on the inner side of petals covering the entire length of anthers and foveolate pollen exine ornamentation. Within the Old World clade, the pentafoliolate species were weakly supported as more closely related to species with both simple and trifoliolate leaves. Furthermore, the ancestral states of tendril apices, inflorescence structure, appendages on the inner side of petals and exine ornamentation of pollen grains were reconstructed on the molecular strict consensus tree. The appendages on the inner side of petals and exine ornamentation of pollen grains were suggested to be important characters in the taxonomy of Parthenocissus, especially for species with trifoliolate leaves. Finally, the previous classifications of Parthenocissus were evaluated within the phylogenetic framework. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, ?? , ??–??.  相似文献   

4.
Hwang DS  Kim BM  Au DW  Lee JS 《Mitochondrial DNA》2012,23(4):308-309
The complete mitochondrial genome was obtained from the assembled genome data sequenced by next-generation sequencer from the marine medaka Oryzias melastigma. The mitochondrial genome sequence was 16,864 bp in size, and the gene order and contents were identical with those of previously reported fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), 4 genes (CO3, ND3, ND4, and Cytb) had incomplete stop codons. The base composition of O. melastigma mitogenome showed high A+T (59.65%) and anti-G bias (8.73%) on the 3rd position of PCGs.  相似文献   

5.
This paper provides the first quantitative cladistic analysis of linyphiid morphology. Classical and novel homology hypotheses for a variety of character systems (male and female genitalia, somatic morphology, spinneret silk spigot morphology, etc.) are critically examined and studied within a phylogenetic context. Critical characters have been illustrated. A sample of linyphiid taxa (nine genera in four subfamilies), five species of Pimoa (Pimoidae), and two other araneoid families (Tetragnathidae and Araneidae, represented by Tetragnatha and Zygiella , respectively) were used to study the implications of the phylogeny of Pimoidae for the systematics of linyphiids. The phylogenetic relationships of these 16 exemplar taxa, as coded for the 47 characters studied, were analysed using numerical cladistic methods. In the preferred cladogram Pimoidae and Linyphiidae are sister groups, Stemonyphantinae are sister group to the remaining linyphiids, and Mynogleninae are sister group to the clade composed of Erigoninae plus Linyphiinae. These results agree with the relationships recently proposed by Wunderlich, except by finding erigonines as the sister group to linyphiines rather than to mynoglenines.  相似文献   

6.
Phylogeny of the flyingfish family Exocoetidae (Teleostei, Beloniformes)   总被引:2,自引:0,他引:2  
The phylogeny of the flyingfish family Exocoetidae is studied cladistically, using 41 morphological characters encompassing early life history, and external and internal features. The monophyly of the family is supported by 10 synapomorphies. Within the family,Oxyporhamphus is the sister group to all other genera, the monophyly of the latter being defined by 10 synapomorphies.Fodiator is the sister group of genera characterized by the presence of chin barbels in juveniles.Parexocoetus is the sister group ofExocoetus, Cypselurus, Prognichthys andHirundichthys, the latter being defined by four synapomorphies. In the latter group,Exocoetus is the sister group of the other three genera. The phylogeny of the Exocoetidae is characterized by the stepwise upgrading of gliding capability, with sequential modifications of the caudal, pectoral and pelvic fins. The subfamily Oxyporhamphinae is resurrected.  相似文献   

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Chinese medaka Oryzias sinensis (Teleostei: Beloniformes) is distributed in China and the western areas of Korea. It differs from the Japanese medaka O. latipes in its morphology and biogeographical distribution in Korea. In this study, we analyzed the complete nucleotide sequence of the mitochondrial genome (mitogenome) of O. sinensis and determined its genomic structure. The complete mitogenome is a circular molecule of 16,654 bp and its structural organization is conserved across diverse vertebrate taxa. On a phylogenetic tree inferred from the nucleotide matrix, partitioned into four regions (i.e., the first and second codon positions of protein-coding genes, and the ribosomal RNA and transfer RNA genes), O. sinensis clustered consistently with O. latipes specimens from China and Korea, with a relatively short branch length, but was separated from O. latipes specimen from Japan. Our findings will allow the resolution of the taxonomic problems of closely related Oryzias species, such as O. sinensis and O. latipes in a future study.  相似文献   

10.
The phylogenetic relationships among medaka fishes of 2 genera, Oryzias and Xenopoecilus, were studied using the nuclear tyrosinase and mitochondrial 12S and 16S rRNA genes. Of the 23 species currently described for these genera, 13 species of Oryzias and 2 species of Xenopoecilus were examined. The tree topologies obtained from the nuclear and mitochondrial data were consistent, indicating that Xenopoecilus is a polyphyletic genus nested within Oryzias. This result suggested the necessity for a systematic study and taxonomic revision of Xenopoecilus. The combined data analysis of all data partitions resulted in a well-resolved tree, with most internal branches supported by high statistical values. Based on our combined data phylogeny, we divided the Oryzias species into three major species groups, namely the latipes, javanicus, and celebensis groups. These three groups corresponded to the three chromosomal groups (biarmed, monoarmed, and fused chromosome groups) previously proposed from karyological analyses. The phylogeographic pattern suggests historical vicariance between Sulawesi Island and the continental shelf.  相似文献   

11.
Skeletal muscles in the whipspider Phrynus longipes are surveyed and compared with those of other chelicerates to clarify the evolutionary morphology and phylogenetic relationships of the arachnids. Representatives of 115 muscle groups are described and illustrated, and their possible functions are proposed. Principal results of this analysis include new functional models for the operation of the pharyngeal and sternocoxal mechanisms in Amblypygi and a greatly expanded list of apparently unique synapomorphies supporting the monophyly of Pedipalpi (= Amblypygi, Schizomida, Thelyphonida).  相似文献   

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通过对核桃扁叶甲3个亚种(指名亚种Gastrolina depressa depressa Baly,淡足亚种G. depressa pallipes Chen和黑胸亚种G. depressa thoracica Baly)的比较形态学研究,结合生物学和生物地理学方面的资料,对其分类地位进行了探讨。从形态上来说,三者的上唇、下唇、后翅和爪的形态区别较小,但是触角、上颚、下颚和受精囊则存在着较大的区别,而且通过超微形态的比较,淡足亚种、黑胸亚种和指名亚种均存在着较为明显的形态区别。动物地理学研究表明,指名亚种和黑胸亚种在我国北纬25°~30°之间有地域重叠,目前仅在部分地区可以通过海拔来区分。但是对于淡足亚种而言,它的分布区与其他两个亚种有着一定的地理隔离,其间并没有重叠区的存在。因此从地理分布上而言,三者也存在着不同。通过上述讨论,本文将核桃扁叶甲三亚种恢复或提升为种,即核桃扁叶甲G. depressa Baly,黑胸扁叶甲G. thoracica Baly和淡足扁叶甲Gastrolina pallipes Chen, stat. Nov.。  相似文献   

15.
The overall most parsimonious hypothesis of relationships based on 200 characters indicates that the Alestidae is the closest relative of Chalceus , a genus previously assigned to the Neotropical Characidae. Chalceus is shifted into the Alestidae, which becomes the only trans-Atlantic family level group within the Characiformes. Various previously proposed suprageneric assemblages within the Alestidae (e.g. Petersiini) failed to delimit monophyletic groups under the intrafamilial phylogenetic analysis. The evaluation of fossil alestids within the context of the phylogeny indicates that the ancestors of Alestes , Arnoldichthys , Brycinus , Bryconaethiops and Hydrocynus evolved prior to the early Eocene (Cuisian of Upper Ypresian), 49–54.8 million years ago, with the fossil Alestoides most closely related to Alestes. The phylogenetic information further indicates a minimum age of 90–112 million years for the Alestidae. Contrary to previous hypotheses, the fossil African Sindacharax was found to be most similar to the clade including the alestid genus Bryconaethiops rather than most closely related to the South American subfamily Serrasalminae. Evaluation of the fossil Mahengecharax carrolli fails to support its hypothesized placement as the sister group to all Recent members of the Alestidae. Two separate episodes of miniaturization and one episode of gigantism occurred within the evolution of the Alestidae.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 1−144. No claim to original US government works.  相似文献   

16.
The phylogenetic position of the Turnicidae (Aves) was unresolved. Historically, they were classified as members of the Struthioniformes, Galliformes, Charadriiformes, Columbiformes or the Gruiformes. In these classifications they had taxonomic rank of order 'Turniciformes' or family 'Turnicidae'. However, most of these studies followed phenetic methodology and used morphological similarity of taxa and plesiomorphic characters to classify Turnix . Recent phylogenetic studies on the basis of morphological character analyses or phenetic comparisons based on DNA-DNA hybridization experiments failed to clarify the phylogenetic realtionship of Turnix and suggested a position as 'incerte sedis', either among the Gruiformes or as the parvclass 'Turnicac'as a sistergroup to the 'Neoaves'.
We studied skeletal and myological material of Turnix to resolve its phylogenetic position. Further, we considered all characters that were previously discussed in literature to classify Turnix and tested them for their potential use in phylogenetic analysis. We added several yet unemployed morphological characters of phylogenetic significance to the analysis. The Struthioniformes, 'Galloanseres', and Columbiformes are each characterized by a clear set of autapomorpies. Only one autapomorphy in known for the Gruiformes but this character is of satisfying consistency and can be found in all families of the Gruiformes (Gruidae, Psophiidae, Aramidae. Rallidae) and Turnix. Turnix and the Rallidae share four complex morphological characters implying a close phylogenetic relationship. The data presented in this paper support the hypothesis that Turnix is a member of the Gruiformes with close relationships to the Rallidae. No evidence was found that would support a parvclass 'Turnicae'as sistergroup to the 'Neoaves'.  相似文献   

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A taxonomic revision of Tectaria from New Caledonia is presented here based on a thorough study of herbarium specimens from New Caledonia and adjacent Pacific islands. Six species of Tectaria are presently recognized in New Caledonia. Tectaria kouniensis and T. pseudosinuata are reduced to synonyms of T. dissecta and T. sinuata, respectively. The morphological limit between T. seemannii and T. sinuata and the confused specimen citations in previous accounts are clarified. Apart from T. dissecta, the other five species, i.e. T. lifuensis, T. moorei, T. seemannii, T. sinuata and T. vieillardii, are mainly distributed in New Caledonia, with only T. seemannii and T. sinuata recently reported also from Vanuatu. A key to species, typification of accepted names and relevant synonyms, and brief comments on the relationships of species are provided.  相似文献   

19.
Iphisa elegans Gray, 1851 is a ground‐dwelling lizard widespread over Amazonia that displays a broadly conserved external morphology over its range. This wide geographical distribution and conservation of body form contrasts with the expected poor dispersal ability of the species, the tumultuous past of Amazonia, and the previously documented prevalence of cryptic species in widespread terrestrial organisms in this region. Here we investigate this homogeneity by examining hemipenial morphology and conducting phylogenetic analyses of mitochondrial (CYTB) and nuclear (C‐MOS) DNA sequence data from 49 individuals sampled across Amazonia. We detected remarkable variation in hemipenial morphology within this species, with multiple cases of sympatric occurrence of distinct hemipenial morphotypes. Phylogenetic analyses revealed highly divergent lineages corroborating the patterns suggested by the hemipenial morphotypes, including co‐occurrence of different lineages. The degrees of genetic and morphological distinctness, as well as instances of sympatry among mtDNA lineages/morphotypes without nuDNA allele sharing, suggest that I. elegans is a complex of cryptic species. An extensive and integrative taxonomic revision of the I. elegans complex throughout its wide geographical range is needed. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 361–376.  相似文献   

20.
以礼草属系统发育的分析   总被引:5,自引:2,他引:5  
基于分支系统学的原理和方法。对禾本科以礼草属进行了系统发育分析,以礼草属是个单系在群,它的32个外部性状选作极性分析。鹅观草属中的肃草作为外类群,采用PAUP程序对矩阵进行运算,获得了1个最简约的谱系分支图。在分支图上,以民礼草属26个种可以归为3个组,但不适合于划分系,3个组中各组包含的种数分别与传统分类的3个组基本吻合,从而支持了传统分类的结果。同时,分支图还展示了各个类群间的亲缘演化关系,其  相似文献   

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