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1.
Individuals belonging to two new species, from two genera Clymenella Verril (Maldanidae) and Mooreonuphis Fauchald (Onuphidae), have been collected and described from a sublittoral bottom area close to Antofagasta, northern Chile. The environment consists of medium to fine sands and the samples have been collected at ca. 60 m depth. Clymenella fauchaldi sp. n. is closely related to Clymenella minorArwidsson, 1911, but clearly differs from other species of the genus in the type of notochaetae, winged capillaries, and neurochaetae, thick acicular spines, that are borne on the first chaetigers. Mooreonuphis colosensissp. n.is related to Mooreonuphis nebulosa (Moore, 1911) and Mooreonuphis peruana (Hartman, 1944), but differs mainly in the form of the mandibles, in the maxillary formula, location of the subacicular hooks on chaetigers, number of the ceratophore rings and the length of the medium and lateral antennae styles.  相似文献   

2.
Cladistics and polychaetes   总被引:33,自引:0,他引:33  
A series of cladistic analyses assesses the status and membership of the taxon Polychaeta. The available literature, and a review by Fauchald & Rouse (1997), on the 80 accepted families of the Polychaeta are used to develop characters and data matrices. As well as the polychaete families, non-polychaete taxa, such as the Echiura, Euarthropoda, Onychophora, Pogonophora (as Frenulata and Vestimentifera), Clitellata, Aeolosomatidae and Potamodrilidae, are included in the analyses. All trees are rooted using the Sipuncula as outgroup. Characters are based on features (where present) such as the prostomium, peristomium, antennae, palps, nuchal organs, parapodia, stomodaeum, segmental organ structure and distribution, circulation and chaetae. A number of analyses are performed, involving different ways of coding and weighting the characters, as well as the number of taxa included. Transformation series are provided for several of these analyses. One of the analyses is chosen to provide a new classification. The Annelida is found to be monophyletic, though weakly supported, and comprises the Clitellata and Polychaeta. The Polychaeta is monophyletic only if taxa such as the Pogonophora, Aeolosomatidae and Potamodrilidae are included and is also weakly supported. The Pogonophora is reduced to the rank of family within the Polychaeta and reverts to the name Siboglinidae Caullery, 1914. The new classification does not use Linnaean categories, and the Polychaeta comprises two clades, the Scolecida and Palpata. The Palpata has the clades Aciculata and Canalipalpata. The Aciculata contains the Phyllodocida and Eunicida. The Canalipalpata has three clades; the Sabellida (including the Siboglinidae) Spionida and Terebellida. The position of a number of families requires further investigation.  相似文献   

3.
Vestimentiferans (Siboglinidae, Polychaeta) live as juveniles and adults in an obligate mutualistic association with thiotrophic bacteria. Since their development is aposymbiotic, metatrochophores of vestimentiferans from the East Pacific Rise colonizing deep-sea hydrothermal vents are infected with the specific symbiont, develop the trophosome, and reduce their digestive system. To gain insight into the anatomy and ultrastructure and to compare this stage with metatrochophores from other siboglinids, we serial sectioned and reconstructed three specimens using light and transmission electron microscopy. The metatrochophore was composed of a prostomium, a small peristomium, two chaetigers (or two chaetigers and one additional segment without chaetae), and a minute pygidium. A digestive system and an intraepidermal nervous system were developed. Larval organs such as the prototroch, the neurotroch, and an apical organ were present, along with juvenile/adult organs such as tentacles, uncini, pyriform glands, and the anlage of the nephridial organ. We propose that in vestimentiferans, the vestimentum is the head arising from the prostomium, peristomium, and the anterior part of the first chaetiger. In frenulates, in contrast, the head is composed on the one hand of the cephalic lobe arising from the prostomium and on the other of the forepart developing from the peristomium and the anterior part of the first chaetiger. In frenulates the muscular septum between the forepart and trunk develops later than the first two chaetigers. Since this septum has no counterpart in vestimentiferans, the forepart-trunk border of frenulates is not considered homologous with the vestimentum-trunk border in vestimentiferans. The obturacular region in vestimentiferans does not appear to be a body region but rather the head appendages arising from the first chaetiger. In contrast, the tentacles in frenulates are prostomial head appendages. In both taxa, the trunk is the posterior part of the first chaetiger, and the opisthosoma is the following chaetigers and the pygidium. Comparisons with other polychaetes suggest that two larval segments are autapomorphic for the monophyletic Siboglinidae.  相似文献   

4.
5.
Euchone analis, the type species of its genus, was collected in high densities and in different size classes from Kongsfjorden, west Spitsbergen. This material has provided the basis for an investigation of the size dependence of characters. Almost all characters used in diagnoses were highly variable, especially the number of abdominal chaetigers forming the anal depression and the shape of the depression. The only relatively constant features are the number of chaetigers anterior to the anal depression and the branchial crown‐to‐body length ratio. A branchial skeleton extension of the radiolar appendages of the dorsal lips was found for the first time within Euchone, and this character has been added to the diagnosis of Euchone. Oriopsis liefdefjordensis and small specimens of E. analis agree in all characters, and O. liefdefjordensis is proposed to be a junior synonym of E. analis. Characters found in O. ingelorae are in accordance with those described for Chone, and we propose assigning O. ingelorae to this genus. The significance of ontogenetic character variations in the Sabellidae is discussed.  相似文献   

6.
The Aeolosomatidae are very small limnetic or terrestrial annelids of apparently simple organisation and uncertain phylogenetic position. They have been placed either at the base of the Clitellata, as a highly derived taxon within the Clitellata closely related to the Naididae, or as their sister group within the „Polychaeta”. A combined immunohistochemical (cLSM) and ultrastructural investigation of the central nervous system and the sense organs in Aeolosoma hemprichi was undertaken to look for characters which might support one of these theories. The position of the brain within the prostomium and the organisation of the ventral nerve cord, with its intraepithelial paired longitudinal nerves lying far apart from each other and the presence of a median longitudinal nerve, are atypical for the Clitellata and clearly differ from the situation found in Naididae. Moreover, the circumoesophageal connectives are bifurcated and enter the brain as dorsal and ventral roots; this arrangement is unknown in Clitellata, in which these connectives are unbranched. An ultrastructural analysis of the ciliated pits located laterally in the furrow between prostomium and peristomium in A. hemprichi and other Aeolosomatidae show that they are in fact nuchal organs. Such presumed chemosensory organs are typical of „Polychaeta” and absent in all Clitellata. Two pairs of ciliary sense organs are present in the prostomium in front of the brain of A. hemprichi. Although similarly organised sensory structures occur in many species of the Clitellata, they differ in position and certain ultrastructural features and are known from other Annelida as well. These results clearly support the exclusion of the Aeolosomatidae from the Clitellata and do not provide any evidence for a sister-group relationship between these two taxa. Accepted: 8 February 2000  相似文献   

7.
Arenicolids comprise a group of four genera in which about 30 nominal species are described. Whereas the biology of many arenicolids is well known, the phylogenetic relationships of these worms are inadequately studied. A close relationship of Arenicolidae and Maldanidae is generally accepted. The phylogenetic relationships of arenicolid taxa were reconstructed based on sequence data of the mitochondrial 16S rRNA gene, the nuclear 18S rRNA gene, and a small fraction of the nuclear 28S rRNA gene. Members of all described arenicolid genera are included in the data set. Phylogenetic analyses were conducted using Maximum Likelihood, Bayesian inference, and Maximum Parsimony. The monophyly of the Maldanidae, as well as of the Arenicolidae is supported by all conducted analyses. Two well supported major clades are highest ranked sister taxa in the Arenicolidae: one containing all Abarenicola species and one containing Arenicola, Arenicolides, and Branchiomaldane. Evidence is given for a closer relationship between the two investigated Branchiomaldane species and Arenicolides ecaudata in the combined analysis. In the light of the molecular data the best explanation for structural and morphological observations is that Branchiomaldane evolved by progenesis.  相似文献   

8.
The rare and endangered Hieracium wiesbaurianum species group shows a scattered relictual distribution in Bavaria. Recently, a couple of populations were discovered which clearly differ from all other populations. If these must be considered as taxonomically independent units, they would be of crucial conservation interest, because of the sole responsibility that Bavaria has for these worldwide endemics. We therefore analysed the genetic structure of H. wiesbaurianum in a comparative approach. Our analysis comprised 37 populations of 13 taxa of H. wiesbaurianum, H. bifidum and H. laevigatum, including three potentially new taxa. We applied amplified fragment length polymorphism (AFLP) analysis and observed only limited genetic variation within populations and taxa. Nevertheless, each studied individual exhibited a unique genotype. An analysis of molecular variance revealed high levels of genetic variation between taxa, but populations were genetically less different. The clear genetic differentiation between the studied taxa was supported by neighbor‐joining cluster analyses and principal coordinate analyses in which every individual was clearly assigned to its respective taxon. The three potentially new taxa were genetically as well differentiated as the other taxa included in our study. This supports the assumption that they should be treated as taxonomically independent units of high conservation interest. Therefore, the genetic analysis confirmed the morphologically based classification of the studied Hieracium taxa. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 112–123.  相似文献   

9.
Atherospio guillei (Laubier and Ramos, 1974) comb. nov. is redescribed based on new material collected during a benthic survey in the German Bight, North Sea. Main characteristics of this species are a deeply incised prostomium, modified neurochaetae on chaetiger 5 superior to a small bundle of capillaries, branchiae fully fused to notopodial lamellae with digitiform distal process from chaetiger 7 over a limited number of succeeding chaetigers, predominately unidentate curved hooks with closely applied sheath from chaetiger 13-15 and a pygidium surrounded by several pairs of lateral cirri. Atherospio is closely related to Pygospiopsis and Pseudatherospio. Interrelationships of these genera are discussed.  相似文献   

10.
The genus Ulocladium represents phaeodictyosporic Hyphomycetes that produce conidia that are essentially obovoid in shape. Previous molecular studies that included Ulocladium and related taxa in Alternaria, Embellisia, and Stemphylium revealed a conflict between morphology and phylogeny, and Ulocladium was supported as polyphyletic with a paraphyletic core group. Moreover, the genus consistently resolved within a larger Alternaria/Ulocladium clade, resulting in paraphyly of Alternaria and questions as to the taxonomic status of Ulocladium. In the present study, 13 Ulocladium species and three genetic loci were included for a more comprehensive systematic analysis of the genus than had previously been conducted. Total genomic DNA was extracted from representative taxa and sequences were determined for the nuclear internal transcribed spacer region, including the 5.8S rDNA gene, and the protein-coding genes glyceraldehyde-3-phosphate dehydrogenase and Alt a1. Subsequent phylogenetic analyses based on maximum parsimony and Bayesian methods included related Alternaria, Embellisia, and Stemphylium spp. Results supported previous findings of polyphyletic and paraphyletic relationships of Ulocladium among other taxa. Ten Ulocladium species clustered into a core Ulocladium clade and all taxa possessed the key diagnostic feature of Ulocladium, namely, conidia essentially obovoid in shape. However, A. cheiranthi and E. indefessa also clustered within this group with high bootstrap support but did not posses this diagnostic feature. This paraphyletic clade resolved basal to the core Alternaria clade with high bootstrap support, unlike previous studies in which its position was imbedded within the primary Alternaria clade. Thus, the status of the genus as an independent lineage and a unique taxon is strongly supported. As previously reported, U. alternariae and U. oudemansii, which posses the key conidium characteristics of Ulocladium, clustered as a separate clade sister to the core Ulocladium clade. Further studies are necessary to determine if these taxa represent an independent lineage or share a common ancestor with other Ulocladium species. Obovoid conidia were poorly represented in the isolate of U. lanuginosum that was included in these analyses (the only U. lanuginosum isolate currently available), and the isolate resolved as A. radicina based upon all three loci sequenced. Based upon these data and the origin of the isolate, which was originally deposited as A. malvae, a reassessment of its identity is supported.  相似文献   

11.
Phyllostachys , a large, economically important genus of woody bamboos. DNA sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) were used in a parsimony analysis. Phyllostachys was well supported as monophyletic with Chimonobambusa as its closest allied genus. The 5S spacer region of nrDNA was investigated but found unsuitable for this purpose. The AFLP analysis showed much higher discriminating power between species and was more useful for phylogenetic reconstruction at this taxonomic level. The combined data were used to review the previous infra-generic classifications. Section Heteroclada Wang & Ye is strongly supported and can be further divided into sub-groups. A group within section Phyllostachys is strongly supported, but a further group of taxa previously included in this section is difficult to place. The ability of the methods to help separate species such as P. sulphurea and investigate genetic diversity at the infra-specific level was also assessed. It is argued that AFLPs could often be the method of choice for phylogenetic studies of closely related taxa for which DNA sequence data provide insufficient resolution. Received 18 April 2000/ Accepted in revised form 10 June 2000  相似文献   

12.
A total of 56 morphological characters were analyzed for 53 cirrospiline species that represent all of the 17 described genera of the tribe. The other taxa of the Eulophinae included in the analysis were six species of six representative genera in the tribe Eulophini, a species of Elasmus (the only genus comprising the tribe Elasmini), and a species of Trichospilus (unplaced). Trichospilus and two of the six genera of Eulophini examined were placed within Cirrospilini. Monophyly of Cirrospilini (when these two genera of Eulophini and Trichospilus are included) and of the cirrospiline genera for which more than one species were examined was supported, but the relationships between the genera were poorly resolved. An exception was Cirrospilus, the largest genus in the Cirrospilini, monophyly of which was not supported to any extent.  相似文献   

13.
A phylogenetic analysis of the order Embioptera is presented with a revised classification based on results of the analysis. Eighty‐two species of Embioptera are included from all families except Paedembiidae Ross and Embonychidae Navás. Monophyly of each of the eight remaining currently recognized families is tested except Andesembiidae Ross, for which only a single species was included. Nine outgroup taxa are included from Blattaria, Grylloblattaria, Mantodea, Mantophasmatodea, Orthoptera, Phasmida and Plecoptera. Ninety‐six morphological characters were analysed along with DNA sequence data from the five genes 16S rRNA, 18S rRNA, 28S rRNA, cytochrome c oxidase I and histone III. Data were analysed in combined analyses of all data using parsimony and Bayesian optimality criteria, and combined molecular data were analysed using maximum likelihood. Several major conclusions about Embioptera relationships and classification are based on interpretation of these analyses. Of eight families for which monophyly was tested, four were found to be monophyletic under each optimality criterion: Clothodidae Davis, Anisembiidae Davis, Oligotomidae Enderlein and Teratembiidae Krauss. Australembiidae Ross was not recovered as monophyletic in the likelihood analysis in which one Australembia Ross species was recovered in a position distant from other australembiids. This analysis included only molecular data and the topology was not strongly supported. Given this, and because parsimony and the Bayesian analyses recovered a strongly supported clade including all Australembiidae, we regard this family also as monophyletic. Three other families – Notoligotomidae Davis, Archembiidae Ross and Embiidae Burmeister, as historically delimited – were not found to be monophyletic under any optimality criterion. Notoligotomidae is restricted here to include only the genus Notoligotoma Davis with a new family, Ptilocerembiidae Miller and Edgerly, new family, erected to include the genus Ptilocerembia Friederichs. Archembiidae is restricted here to include only the genera Archembia Ross and Calamoclostes Enderlein. The family group name Scelembiidae Ross is resurrected from synonymy with Archembiidae (new status) to include all other genera recently placed in Archembiidae. Embiidae is not demonstrably monophyletic with species currently placed in the family resolved in three separate clades under each optimality criterion. Because taxon sampling is not extensive within this family in this analysis, no changes are made to Embiidae classification. Relationships between families delimited herein are not strongly supported under any optimality criterion with a few exceptions. Either Clothodidae Davis (parsimony) or Australembiidae Ross (Bayesian) is the sister to the remaining Embioptera taxa. The Bayesian analysis includes Australembiidae as the sister to all other Embioptera except Clothididae, suggesting that each of these taxa is a relatively plesiomorphic representatative of the order. Oligotomidae and Teratembiidae are sister groups, and Archembiidae (sensu novum), Ptilocerembiidae, Andesembiidae and Anisembiidae form a monophyletic group under each optimality criterion. Each family is discussed in reference to this analysis, diagnostic combinations and taxon compositions are provided, and a key to families of Embioptera is included.  相似文献   

14.
The Olenidae stands out for its abundance and biostratigraphical importance, especially in the Lower Palaeozoic rocks of northwestern Argentina. Their phylogenetic relationships have been traditionally determined stratigraphically and by direct morphological comparison. This study reports the first formal phylogenetic analysis of olenids. Eighty‐six characters (24 quantitative and 62 qualitative) were coded for 65 taxa (58 olenids). Quantitative characters were treated both as discrete and as continuous variables. To explore the best way of character coding for this group, continuous characters were coded as: median, log‐median, normalized and rescaled. Maximum parsimony and implied weighting were used as optimality criteria. A phylogenetic hypothesis more consistent with traditional taxonomy was reconstructed with both quantitative and qualitative partitions. All the trees obtained with quantitative characters coded as continuous and rescaled are better resolved, and those topologies were more similar among them. This treatment also reflects more effectively the behaviour of the original variables. Olenidae is not a monophyletic clade: Andrarina costata and Aphelaspis australis are included within the ingroup, as sister clade of Olenus gibbosus. Also, the results suggest that members of the Hypermecaspidinae constitute a new family within the Order Olenida. The traditional taxonomic scheme at subfamily level is partially supported. Triarthrinae and ‘pelturinds’ are recovered as monophyletic clades, but Oleninae is polyphyletic. This study proves, through a formal cladistic analysis, that characters disregarded by traditional taxonomy can be uncovered. Finally, this is the first step towards achieving a classification of the Olenidae taking into account the evolutionary process involved in its diversification history.  相似文献   

15.
16.
This study examined subfamilial relationships within Braconidae, using 4 kb of sequence data for 139 taxa. Genetic sampling included previously used markers for phylogenetic studies of Braconidae (28S and 18S rDNA) as well as new nuclear protein‐coding genes (CAD and ACC). Maximum likelihood and Bayesian inference of the concatenated dataset recovered a robust phylogeny, particularly for early divergences within the family. This study focused primarily on non‐cyclostome subfamilies, but the monophyly of the cyclostome complex was strongly supported. There was evidence supporting an independent clade, termed the aphidioid complex, as sister to the cyclostome complex of subfamilies. Maxfischeria was removed from Helconinae and placed within its own subfamily within the aphidioid complex. Most relationships within the cyclostome complex were poorly supported, probably because of lower taxonomic sampling within this group. Similar to other studies, there was strong support for the alysioid subcomplex containing Gnamptodontinae, Alysiinae, Opiinae and Exothecinae. Cenocoeliinae was recovered as sister to all other subfamilies within the euphoroid complex. Planitorus and Mannokeraia, previously placed in Betylobraconinae and Masoninae, respectively, were moved to the Euphorinae, and may share a close affiliation with Neoneurinae. Neoneurinae and Ecnomiinae were placed as tribes within Euphorinae. A sister relationship between the microgastroid and sigalphoid complexes was also recovered. The helconoid complex included a well‐supported lineage that is parasitic on lepidopteran larvae (macrocentroid subcomplex). Helconini was raised to subfamily status, and was recovered as sister to the macrocentroid subcomplex. Blacinae was demoted to tribal status and placed within the newly circumscribed subfamily Brachistinae, which also contains the tribes Diospilini, Brulleiini and Brachistini, all formerly in Helconinae.  相似文献   

17.
Phylogenetic relationships withinChusquea,a diverse genus of neotropical woody bamboos, and among selected members of the Bambusoideae were explored usingrpl16intron sequence data from the chloroplast genome. Mechanisms of mutation, including slipped-strand mispairing, secondary structure, minute inversions, and base substitutions, were examined within therpl16intron, and their effects on sequence alignment and phylogenetic analysis were investigated. Thirty-five bamboo sequences were generated and two separate matrices were analyzed using maximum parsimony. In the first, 23 sequences fromChusquea,1 ofNeurolepis,and 3 outgroups were included.Neurolepiswas supported as sister toChusquea, Chusqueawas strongly supported as a monophyletic lineage, and three species ofChusqueasubg.Rettbergiawere resolved as the most basal clade within the genus. In the second analysis, 15 sequences, 14 from across the subfamily and 1 outgroup, were included. A Bambusoideae clade was recovered with the Olyreae/Parianeae (herbaceous bamboos) and the Bambuseae (woody bamboos) each supported as monophyletic. Two clades corresponding to temperate and tropical woody bamboos were derived within the Bambuseae and the tropical taxa were further split into New World and Old World clades. Therpl16intron in bamboos was found to be susceptible to frequent length mutations of multiple origins, nonindependent character evolution, and regions of high mutability, all of which created difficulties in alignment and phylogenetic analysis; nonetheless therpl16intron is phylogenetically informative at the inter- and intrageneric levels in bamboos.  相似文献   

18.
Abstract Dictyoptera, comprising Blattaria, Isoptera, and Mantodea, are diverse in appearance and life history, and are strongly supported as monophyletic. We downloaded COII, 16S, 18S, and 28S sequences of 39 dictyopteran species from GenBank. Ribosomal RNA sequences were aligned manually with reference to secondary structure. We included morphological data (maximum of 175 characters) for 12 of these taxa and for an additional 15 dictyopteran taxa (for which we had only morphological data). We had two datasets, a 59‐taxon dataset with five outgroup taxa, from Phasmatodea (2 taxa), Mantophasmatodea (1 taxon), Embioptera (1 taxon), and Grylloblattodea (1 taxon), and a 62‐taxon dataset with three additional outgroup taxa from Plecoptera (1 taxon), Dermaptera (1 taxon) and Orthoptera (1 taxon). We analysed the combined molecular?morphological dataset using the doublet and MK models in Mr Bayes , and using a parsimony heuristic search in paup . Within the monophyletic Mantodea, Mantoida is recovered as sister to the rest of Mantodea, followed by Chaeteessa; the monophyly of most of the more derived families as defined currently is not supported. We recovered novel phylogenetic hypotheses about the taxa within Blattodea (following Hennig, containing Isoptera). Unique to our study, one Bayesian analysis places Polyphagoidea as sister to all other Dictyoptera; other analyses and/or the addition of certain orthopteran sequences, however, place Polyphagoidea more deeply within Dictyoptera. Isoptera falls within the cockroaches, sister to the genus Cryptocercus. Separate parsimony analyses of independent gene fragments suggest that gene selection is an important factor in tree reconstruction. When we varied the ingroup taxa and/or outgroup taxa, the internal dictyopteran relationships differed in the position of several taxa of interest, including Cryptocercus, Polyphaga, Periplaneta and Supella. This provides further evidence that the choice of both outgroup and ingroup taxa greatly affects tree topology.  相似文献   

19.
20.
Abstract

Gymnospermium is a small genus of 7–12 taxa subject to diverging taxonomic treatments and distributed from east China to the Balkans. The recent discovery of Gymnospermium in the S-Apennines posed questions about origin and identity. Accordingly, we performed a systematic investigation by means of morphological, karyological and molecular tools. All populations were diploid with 2n = 14 as for the Balkan G. scipetarum (incl. G. maloi), and also morphology suggested a close affinity to the latter. However, the Italian populations differed from typical G. scipetarum by the lower stamen:petal length and style:carpel length. By including all European and most Asian taxa in a phylogenetic analysis, we shed new light into the species-level relationships in this genus. In the combined ITS-trnL-F phylogeny, two major clades were retrieved. One included the central Asian and eastern European taxa plus the Greek endemic G. peloponnesiacum sister to G. odessanum, and one the Balkan and Apennine populations. Such findings further corroborated that the Apennine plant belong to G. scipetarum. The native status of the Italian population is supported by exclusive SNPs in both ITS1 and trnL-F sequences. Along with morphological evidence, this allows to refer it to the new subspecies G. scipetarum subsp. eddae.  相似文献   

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