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1.
Rock-dwelling gastropods are usually patchily distributed in limestone habitats, presumably have low active and passive dispersal ability and often represent narrow-ranged endemic taxa. Their current taxonomy is predominantly shell morphology based, and it remains unknown whether the morphologically differentiated and geographically separated populations represent phylogenetic clades. In this study, we analysed the hyperdiverse, terrestrial door snail genus Montenegrina. Based on the current taxonomy defined by shell morphology, it contains 29 species and 106 subspecies distributed in the Balkan region. The constructed phylogenetic tree using three mitochondrial markers was used to test whether it agrees with the current taxonomy. In this comprehensive tree, about half of the species and subspecies are monophyletic. Some of the paraphylies could be reasonably resolved by taxonomic changes; that is, some subspecies should be reassigned or raised to species level. Other incongruencies probably arose due to introgression even between distant clades. The histone genes turned out to be unsuitable for elucidating the phylogeny of Montenegrina. In the species-delimitation tests, considerably more molecular operational taxonomic units were delimited than the number of presently described species. The present data indicate that (a) shell morphology-based taxonomy and taxon recognition can be problematic in such a large and morphologically highly variable genus; (b) the potential error due to incomplete sampling presents a problem in a genus as variable as Montenegrina; (c) multi-locus analyses should be conducted to arrive at a better basis for species delimitation; and (d) integrative approaches including genetic as well as morphological/anatomical data from a comprehensive geographic sample are necessary.  相似文献   

2.
Delimitation of closely related species is often hindered by the lack of discrete diagnostic morphological characters. This is exemplified in bumblebees (genus Bombus). There have been many attempts to clarify bumblebee taxonomy by using alternative features to discrete morphological characters such as wing shape, DNA, or eco‐chemical traits. Nevertheless each approach has its own limitations. Recent studies have used a multisource approach to gather different lines of speciation evidence in order to draw a strongly supported taxonomic hypothesis in bumblebees. Yet, the resulting taxonomic status is not independent of selected evidence and of consensus methodology (i.e. unanimous procedure, majority, different weighting of evidence). In this article, we compare taxonomic conclusions for a group of taxonomically doubtful species (the Bombus lapidarius‐group) obtained from the four commonly used lines of evidence for species delimitation in bumblebees (geometric morphometric of wing shape, genetic differentiation assessment, sequence‐based species delimitation methods and differentiation of cephalic labial gland secretions). We ultimately aim to assess the usefulness of these lines of evidence as components of an integrative decision framework to delimit bumblebee species. Our results show that analyses based on wing shape do not delineate any obvious cluster. In contrast, nuclear/mitochondrial, sequence‐based species delimitation methods, and analyses based on cephalic labial gland secretions are congruent with each other. This allows setting up an integrative decision framework to establish strongly supported species and subspecies status within bumblebees.  相似文献   

3.
Recent studies on the endemic Canarian genus Purpuraria have shown that the taxonomy of its only recognized species (P. erna) is probably erroneous. In this study, an integrative revision of the genus is performed, based on a large number of specimens and geographical sampling. As a result, (1) the diagnostic characters at the genus level are re‐described, (2) Purpuraria magna n. sp. based on morphological, morphometric and genetic data is described and (3) the taxonomic status of a formerly described subspecies is clarified. Intraspecific and interspecific morphometric differences have been found, indicating that the genus is undergoing a process of morphological diversification. Nevertheless, the possibility of interspecific mating between individuals of the two species is suggested, because no significant differences have been found between their respective calling songs. Genetic analyses using mitochondrial and nuclear DNA sequences suggest that P. erna and P. magna are recent species with evidences of secondary contact episodes in the past.  相似文献   

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邹武  曾菊平  姜梦娜  王渌  周善义  张江涛 《昆虫学报》2021,64(11):1338-1349
亚种是种的一个亚单位,由于分类学上的不同定义和主观性而受到质疑。然而,在分类学实践中,所有试图用不同的术语取代亚种或完全放弃亚种的尝试都是不可接受的。亚种同样是生物多样性的重要组成,有一定独特性,为自然进程的一部分,具有保护研究价值。本文基于亚种概念、特征认为亚种分类需参考地理隔离(如异域分布)与表型差异2个原则。我们以珍稀喙凤蝶属Teinopalpus为例,系统收集亚种分类文献,采集该属亚种的地理分布、形态描述与差异等信息,综合分析该属蝶类的亚种分类现状、问题与原因。1843-2007年喙凤蝶属金带喙凤蝶T. imperialis及其姊妹种金斑喙凤蝶T. aureus各自记录了8个亚种。然而,部分亚种记录于同一行政区,如金带喙凤蝶T. i. imperialis, T. i. himalaicus与T. i. behludinii 均在中国四川有记录,而金斑喙凤蝶在中国浙江有2个亚种记录,这显示名称应用的不确定性。考虑到两姊妹种同域分布在亚洲东南部,通过比对亚种正模所在地植被群落(biome)、生态区(ecoregion)的一致性判定地理隔离,发现金带喙凤蝶(覆盖3个植被群落)比金斑喙凤蝶(仅覆盖1个)的种下生态位分化程度更高。而据所处生态区的一致性,建议将金带喙凤蝶亚种分类修订为T. i. imperialis, T. i. himalaicus, T. i. miecoae, T. i. behludinii, T. i. imperatrix(含T. i. bhumipholi), T. i.gillesi和T. i. gerritesi 7个;金斑喙凤蝶亚种分类修订为T. a. aureus(含T. a. wuyiensis, T. a. guangxiensis与T. a. nagaoi), T. a. eminens(含T. a. laotiana), T. a. shinkaii与T. a. hainani 4个。由于可参考标本少,喙凤蝶属亚种确立时可用形态比对信息有限、不完整(如只依据单性的形态比对结果等),易“过度亚种化”。珍稀亚种分类问题(如“过度亚种化”、信息不确定性等)影响其保护措施,因为管理者常需权衡投入成本与成效、明确优先保护区域或对象,并以此做出决策。因此,在更多确定信息未获得前,不建议进行亚种分类。  相似文献   

6.
RICE, E. L., 1989. A statistical morphological analysis and taxonomic revision of the genus Xiphophora (Fucaceae). Xiphophora is a brown seaweed endemic to the cool temperature rocky shores of Australia and New Zealand. The two species, X. chondrophylla and X. gladiata have previously been separated by morphological criteria. However, the differences betweeen them in these characters were largely size-related, resulting in taxonomic confusion. In particular, the presence of X. gladiata in New Zealand has been disputed. In this study, a series of discriminant function analyses were performed, based on a suite of morphological characters collected from each species throughout a major portion of their geographic ranges. The results show conclusively that the present taxonomy of Xiphophora is untenable. This genus is composed of two species, but these are distributed latitudinally (either side of the 40oS parallel). Each species contains two allopatric subspecies; one in Australia and the other in New Zealand. A formal taxonomic revision of the genus is presented.  相似文献   

7.
Cryptic diversity not only introduces confusion to taxonomic studies, but it also poses major challenges to conservation and environmental legislation. One such troubling group are the Mountain Dragons in the genus Diploderma in Southwest China. Previous studies have suggested that the genus contains considerable cryptic diversity, particularly in the D. flaviceps complex. Owing to taxonomic confusion, micro‐endemic lineages are still neglected by the Chinese wildlife protection laws, despite their urgent conservation needs. Combining multivariate morphological and multi‐locus phylogenetic data, we provide the first integrative systematic revision of the genus Diploderma. Specifically, we confirm that the six examined populations of D. cf. flaviceps from the upper Jinsha and Yalong River Valleys in Sichuan and Yunnan Provinces represent six cryptic, undescribed lineages, and we describe each of them as a new species. With the updated taxonomy and distribution information, we discuss the taxonomy of the D. flaviceps complex in Southwest China, provide an updated diagnostic key along with distributional ranges for all species of the genus, and discuss some of the suspicious records of other congeners in China. Lastly, we evaluate the IUCN status of each of the six new species and highlight the major challenges for Diploderma conservation in China due to delayed environmental legislation and misleading conservation assessments.  相似文献   

8.
淫羊藿是我国特有且传统的重要药用植物,逐渐步入大宗品种行列。物种的准确鉴定是药效保障和用药安全的前提,为促进其资源的合理开发和利用,该文对淫羊藿属分类学研究进行系统梳理,并对其中存在的问题及存疑类群进行阐述。淫羊藿属共发表68种,中国58种(85.3%),其中57种为特有分布,具有显著的资源优势。淫羊藿属中国类群的分类学研究较为特殊,共26种集中发表于1990s,共31种(53.4%)为国外研究者命名,且绝大多数依据少量栽培个体命名。由于缺乏广泛的形态调查和性状变异分析,导致大量类群的形态描述不准确或不全面,后续20个类群被归并或降级。依据栽培个体命名的类群是补充描述和分类修订的重点。花色、根茎类型、花茎叶的数量及着生方式等性状在中国类群中存在广泛变异。经分类修订后,该属目前包括46种、1亚种和2变种。淫羊藿属中国组类群仍处于活跃进化中,其形态变异复杂,种间关系无法得到解决,为该属分类的最大挑战。但种质资源的研究和利用需要建立在清晰的分类学基础上。未来研究应基于居群调查,完善各物种的形态描述;在此基础上,整合形态变异特征、地理分布格局和基因序列特征,检测自然种间杂交事件,从而揭示物种的分化和进化历程。  相似文献   

9.
Blue sheep, Pseudois nayaur, is endemic to the Tibetan Plateau and the surrounding mountains, which are the highest‐elevation areas in the world. Classical morphological taxonomy suggests that there are two subspecies in genus Pseudois (Bovidae, Artiodactyla), namely Pseudois nayaur nayaur and Pseudois nayaur szechuanensis. However, the validity and geographic characteristics of these subspecies have never been carefully discussed and analyzed. This may be partially because previous studies have mainly focused on the vague taxonomic status of Pseudois schaeferi (dwarf blue sheep). Thus, there is an urgent need to investigate the evolutionary relationship and taxonomy system of this genus. This study enriches a previous dataset by providing a large number of new samples, based on a total of 225 samples covering almost the entire distribution of blue sheep. Molecular data from cytochrome b and the mitochondrial control region sequences were used to reconstruct the phylogeny of this species. The phylogenetic inferences show that vicariance plays an important role in diversification within this genus. In terms of molecular dating results and biogeographic analyses, the striking biogeographic pattern coincides significantly with major geophysical events. Although the results raise doubt about the present recognized distribution range of blue sheep, they have corroborated the validity of the identified subspecies in genus Pseudois. Meanwhile, these results demonstrate that the two geographically distinct populations, the Helan Mountains and Pamir Plateau populations, have been significantly differentiated from the identified subspecies, a finding that challenges the conventional taxonomy of blue sheep.  相似文献   

10.
Progress in molecular techniques together with the incorporation of phylogenetic analyses of DNA into taxonomy have caused an increase in the number of species’ discoveries in groups with morphological characters that are difficult to study or in those containing polytypic species. But some emerged criticisms plead for a taxonomic conservatism grounded either on the requirement of providing evidences of morphological distinctiveness or reproductive barriers to erect new species names. In a case study of taxonomic research on Neotropical frogs, we combine several lines of evidence (morphological characters, prezygotic reproductive isolation and phylogenetic analyses of mitochondrial DNA) to test the status of 15 nominal species and to assess the degree of agreement of the different lines of evidence. Our study reveals that morphology alone is not sufficient to uncover all species, as there is no other single line of evidence independently. Full congruence between lines of evidence is restricted to only four out of the 15 species. Five species show congruence of two lines of evidence, whereas the remaining six are supported by only one. The use of divergence in morphological characters seems to be the most conservative approach to delineate species boundaries because it does not allow the identification of some sibling reciprocally monophyletic species differing in their advertisement calls. The separate analysis of differences in advertisement calls (evidence of reproductive isolation) or of phylogenetic data alone also shows limitations, because they do not support some morphological species. Our study shows that only an integrative approach combining all sources of evidence provides the necessary feedback to evaluate the taxonomic status of existing species and to detect putative new ones. Furthermore, the application of integrative taxonomy enables the identification of hypotheses about the existence of species that will probably be rejected or changed, and those that can be expected to persist.  相似文献   

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Metapenaeopsis Bouvier, 1905 is the most diverse genus within Penaeidae. Metapenaeopsis shrimps exhibited subtle morphological differences, which make identification a difficult task based on taxonomic keys alone. In this study, we carried out DNA barcoding and phylogenetic analyses to examine taxonomy and phylogeny of genus Metapenaeopsis based on mitochondrial (COI) and nuclear (PEPCK and NaK) genes. Despite limited performance of DNA barcoding in delineating Metapenaeopsis shrimps, it questioned the taxonomic status of the two subspecies, Metapenaeopsis mogiensis intermedia and Metapenaeopsis mogiensis mogiensis, as well as three separate species: Metapenaeopsis provocatoria longirostris, Metapenaeopsis quinquedentata and Metapenaeopsis velutina. The major pattern of relationships between all studied taxa of Metapenaeopsis was similar across all analytical methods in which species with one-valved petasma were genetically distinct from those with two-valved petasma. As expected from morphology, the remaining species with stridulating organ constituted a strongly supported clade. In contrast, a paraphyletic clade was resolved for species without stridulating organ which contradicts Crosnier's morphological classification scheme for Metapenaeopsis. Overall, the present molecular data indicated that the shape of petasma and stridulating organ were both phylogenetically significant morphological characters for this genus, adding further evidence for the Crosnier's proposal.  相似文献   

13.
The brassoline genus Catoblepia is revised: eight new subspecies are described, nine new synonymies established, the status of four species and subspecies is revised, one species ( singularis ) is returned to the genus Opsiphanes and ten lectotypes are designated. All known holotypes (20) and lectotypes (10) are figured, many for the first time. The refined taxonomy reveals an interesting pairing of the Andean subspecies of xanthicles and berecynthia and it is suggested that diese may be mimetic pairs. There is close agreement in the distribution of the Andean species and subspecies with die endemic centres previously recognized; east of the Andes, however, diere is no close correspondence and each of the subspecies has, in general, a distribution across several endemic centres.  相似文献   

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在扫描电镜下观察了分布于南半球的柏科Cupressaceae单种属Pilgerodendron u viferum及其相关类群的代表种Austrocedrus chilensis、Libocedrus plumosa和Papuacedr us papuana叶角质层内外表面的微形态特征。发现Pilgerodendron uviferum叶角质层外表面 光滑,不具Florin环,而其余3个属的代表种均有明显的Florin环;且仅L.plumosa叶角质层外 表面有乳状突起。观察结果支持传统的观点,即将P.uviferum作为独立的属;不支持基于DNA 分析的结果,即将P.uviferum归并到Libocedrus属。发现Papuacedrus papuana叶角质层外表 面有许多明显的小凹陷,与其相对应的叶角质层内表面有凹陷的小狭缝,该性状以前未见报 道。  相似文献   

16.
WE CONDUCTED A COMPREHENSIVE MOLECULAR PHYLOGENETIC STUDY FOR A GROUP OF CHAMELEONS FROM MADAGASCAR (CHAMAELEONIDAE: Calumma nasutum group, comprising seven nominal species) to examine the genetic and species diversity in this widespread genus. Based on DNA sequences of the mitochondrial gene (ND2) from 215 specimens, we reconstructed the phylogeny using a Bayesian approach. Our results show deep divergences among several unnamed mitochondrial lineages that are difficult to identify morphologically. We evaluated lineage diversification using a number of statistical phylogenetic methods (general mixed Yule-coalescent model; SpeciesIdentifier; net p-distances) to objectively delimit lineages that we here consider as operational taxonomic units (OTUs), and for which the taxonomic status remains largely unknown. In addition, we compared molecular and morphological differentiation in detail for one particularly diverse clade (the C. boettgeri complex) from northern Madagascar. To assess the species boundaries within this group we used an integrative taxonomic approach, combining evidence from two independent molecular markers (ND2 and CMOS), together with genital and other external morphological characters, and conclude that some of the newly discovered OTUs are separate species (confirmed candidate species, CCS), while others should best be considered as deep conspecific lineages (DCLs). Our analysis supports a total of 33 OTUs, of which seven correspond to described species, suggesting that the taxonomy of the C. nasutum group is in need of revision.  相似文献   

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The polymorphic genus Petaurista includes a group of diverse species and subspecies that are adapted for gliding and arboreal life. This morphological diversity has resulted in taxonomic discrepancies, and molecular phylogenetic studies have been limited by taxon sampling. To clarify this controversial taxonomy, we used the cytochrome b gene to reconstruct the phylogeny to obtain a more accurate picture of the evolutionary relationships, species differentiation and divergence pattern of Petaurista. The results revealed a significant inconsistency between taxonomic designations, phylogeny and genetic distances. When 6 recognized species were included, species delimitation revealed 15 putative species, a finding that warrants a comprehensive morphological diagnosis and a re-assessment of the species status. The validity of P. caniceps and P. marica was discussed. An estimation of the molecular divergence time demonstrated that the diversification and speciation of Petaurista began during the later Miocene and may have been affected by the uplifting of the Qinghai-Tibet plateau and subsequent climate change.  相似文献   

19.
  • 1 Pinnipeds are charismatic but difficult to study, and taxonomy is poorly understood. An accurate taxonomic framework is essential for studies of biogeography, ecology and conservation.
  • 2 Morphologic and genetic criteria used to recognize pinniped species and subspecies are evaluated individually for all taxa in the three families: Otariidae (sea lions and fur seals), Odobenidae (walruses) and Phocidae (seals). We advocate a pragmatic approach that, in general, follows the Evolutionary Species Concept and ‘diagnosability’ criterion for subspecies delimitations.
  • 3 Of the 33 species, all have at least two lines of evidence to distinguish them, and of the 29 subspecies, 24 have at least one line of evidence, but five have inadequate support. We present a composite phylogeny for pinnipeds.
  • 4 We propose that the genus Arctocephalus be limited to Arctocephalus pusillus, and we resurrect the name Arctophoca for at least six species and subspecies.
  • 5 We recommend large sample sizes and broad, random sampling in further research on pinniped taxonomy. Taxa should be described based on robust statistical analysis, not by arbitrary division of characters, and molecular research should include analysis of mtDNA and nuDNA.
  • 6 Finally, we offer suggestions for further taxonomic research (on hybridization in otariids, and to allow consideration of life history data in sampling) in an effort to improve our understanding of pinniped diversity. Even for taxa which are already protected, better understanding of their taxonomy can only enhance their conservation status and facilitate efforts to protect their habitats.
  相似文献   

20.
陈晗  丁刚  孙炳达  张争  王龙  陈娟 《菌物学报》2021,40(5):1200-1215
篮状菌属真菌在空气、土壤中分布广泛,有些种类是重要的工业酶及色素生产菌,有些则可以引起食品的污染变质,还有些种是引起浅层或散播性感染的条件致病菌,如马尔尼菲篮状菌.篮状菌属在传统分类学上是一个有性型属,随着多相分类以及"一种真菌一个名称"概念的广泛普及,该属的概念已经发生了较大的变化,目前全世界已报道177个种.本文基...  相似文献   

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