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Sponges belonging to the class Homoscleromorpha have become a pivotal group to help understand early metazoan evolution. However, their complex systematics and cryptic habitat (e.g. dead coral, or under/amongst coral rubble or rock), hinders the recognition and classification of species. An extensive study carried out in coral reefs from the Mexican Pacific coast, Revillagigedo and Clipperton Islands, yielded 21 specimens and five species of Plakinidae: Plakortis albicans, Plakinastrella clippertonensis, P lakina muricyae sp. nov. , P lakina paradilopha sp. nov. , and P lakortis clarionensis sp. nov. Fragments of cytochrome c oxidase subunit I (cox1) and cytochrome b (cob) mtDNA were sequenced to generate DNA‐barcoding of some species and to determine their phylogenetic relationships with other homosclermorphs. Molecular and morphological data placed Plakina muricyae sp. nov. together with the morphologically related species Plakina monolopha (Plakina monolopha‐complex), whereas Plakina paradilopha sp. nov. seems to belong to the Plakina dilopha complex. According to spicule morphology and size, Plakortis albicans had been considered to be in the Plakortis simplex‐complex. However, this was not supported by our molecular data and Plakortis albicans clustered with Plakinastrella sp. here. This is the first time that the standard cox1 ‘barcoding fragment’ has been analysed for the systematics of Plakinidae, which showed to Plakina as a monophyletic group, which is congruent with the morphological hypothesis. The genus Plakina is here recorded for first time from Mexican Pacific waters. A taxonomic key for Homoscleromorpha species from the eastern Pacific region is also included. © 2014 The Linnean Society of London  相似文献   

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We describe a species of Odontites, O. bolligeri E.Rico, L.Delgado & Herrero, endemic to the south‐eastern Iberian Peninsula and north Africa, from Morocco to Tunisia. This species belongs to the O. purpureus group and corresponds to the taxon that the monographer Markus Bolliger called O. squarrosus subsp. squarrosus. However, according to the International Code of Botanical Nomenclature (ICBN), this is an invalid name, and hence we propose a new name for these plants here. Drawings of the new species are also supplied. In addition, we compare and discuss the other species of the O. purpureus group, propose a key for them and include a karyological study of the two Iberian species of the group. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 701–708.  相似文献   

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A new species of Daptonema is described based upon morphological characters and 18S rRNA sequence. Daptonema matrona sp. nov. was collected in Pina Basin (north‐eastern Brazil). It differs from all other species of the genus by the presence of reduced cephalic setae and straight spicules. These features require an adaptation of the generic diagnosis. Moreover, the females are characterized by intra‐uterine development of the offspring, considered herein as their major autapomorphic feature. Molecular systematic analyses supported Daptonema matrona sp. nov. as a distinct genetic and evolutionary lineage. The data also indicate hypotheses of taxonomic synonymies amongst some related taxa from Xyalidae as well as the paraphyly of Daptonema. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 1–15.  相似文献   

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Summary. The genus Calliptamus contains swarming orthopterans that cause serious damage in Algerian agricultural systems. However, it remains difficult to identify species within this genus; a thorough understanding of the group’s systematics and the utilization of novel taxonomic criteria are needed. We used morphological analysis along with two other methods of species identification – chemotaxonomy with cuticular compounds and DNA barcoding involving the COI gene – to classify 81 individual grasshoppers collected at two different sites in the Sétif region (northeastern Algeria). The chemotaxonomic analyses yielded ambiguous results, but DNA barcoding allowed us to differentiate two Calliptamus species found in Algeria: Calliptamus barbarus (Costa 1836), and Calliptamus wattenwylianus (Pantel 1896). Several morphological criteria used in identification keys appear to reflect differences among morphotypes rather than differences between species, and their taxonomic specificity is not supported by the barcoding data. The number of spines on the hind tibia is the only morphological criterion that reflected genetic differences between species; it is thus considered to be a taxonomically useful feature for identifying species in this genus.  相似文献   

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Mitochondrial ribosomal gene sequences were used to investigate the status of several populations of hydromedusae belonging to the genus Turritopsis (family Oceaniidae). Several nominal species have been described for this genus, but most of them had been synonymized and attributed to one cosmopolitan species, Turritopsis nutricula . A recent revision based on morphological and reproductive characters, however, has shown that many different populations can be distinguished and that several of the nominal Turritopsis species are likely valid biological species. Our investigation using molecular sequence data of 16S mitochondrial gene confirms these results. The Mediterranean Turritopsis must be attributed to Turritopsis dohrnii and the Turritopsis of New Zealand must be referred to Turritopsis rubra . The situation of the Japanese Turritopsis is more complex, though all sampled populations are clearly distinct from T. nutricula , a species likely confined to the Western Atlantic. The Japanese Turritopsis fall into three widely separated lineages. One of them, corresponding likely to Turritopsis pacifica , is closely related to T. rubra . A second clade, which potentially represents an as yet undescribed species, produces smaller medusae than T. pacifica and is morphologically distinguishable from it. Finally, a third group was distinguished by a single haplotype sequence that is identical with a Mediterranean sample of T. dohrnii . It is postulated that the last group of Japanese Turritopsis is likely a recent introduction, most probably by human activity. A survey of all known and potentially valid Turritopsis species is given in table format to facilitate identifications and future revisory work.  相似文献   

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We constructed a phylogeny of the ground beetle subgenus Nialoe ( s. lat. ), genus Pterostichus (Coleoptera: Carabidae) based on two mitochondrial (cytochrome oxidase I and 16S ribosomal DNA) and one nuclear (28S ribosomal DNA) gene sequences. Thirty-three representative species of the group and three outgroup species were analyzed. The resultant trees (maximum parsimonious, maximum likelihood and Bayesian trees of the combined data of the three gene sequences) indicated that there are two large and three small lineages in the group, some of which were supported by a previous morphology-based phylogeny. In all the analyses, the small lineage composed of two Korean species is sister to the rest of the subgenus, but relationships of other four lineages differed among the analyses and remained unresolved. The implications of the present results are discussed in terms of taxonomy and biogeography of the group.  相似文献   

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Numerous deep‐sea species have apparent widespread and discontinuous distributions. Many of these are important foundation species, structuring hard‐bottom benthic ecosystems. Theoretically, differences in the genetic composition of their populations vary geographically and with depth. Previous studies have examined the genetic diversity of some of these taxa in a regional context, suggesting that genetic differentiation does not occur at scales of discrete features such as seamounts or canyons, but at larger scales (e.g. ocean basins). However, to date, few studies have evaluated such diversity throughout the known distribution of a putative deep‐sea species. We utilized sequences from seven mitochondrial gene regions and nuclear genetic variants of the deep‐sea coral Paragorgia arborea in a phylogeographic context to examine the global patterns of genetic variation and their possible correlation with the spatial variables of geographic position and depth. We also examined the compatibility of this morphospecies with the genealogical‐phylospecies concept by examining specimens collected worldwide. We show that the morphospecies P. arborea can be defined as a genealogical‐phylospecies, in contrast to the hypothesis that P. arborea represents a cryptic species complex. Genetic variation is correlated with geographic location at the basin‐scale level, but not with depth. Additionally, we present a phylogeographic hypothesis in which P. arborea originates from the North Pacific, followed by colonization of the Southern Hemisphere prior to migration to the North Atlantic. This hypothesis is consistent with the latest ocean circulation model for the Miocene.  相似文献   

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The Hippasterinae is a subfamily within the Goniasteridae, consisting of five genera and 26 species, which occur in cold‐water settings ranging from subtidal to abyssal depths. All known genera were included in a cladistic analysis resulting in two most parsimonious trees, supporting the Hippasterinae as monophyletic. Our review supports Sthenaster emmae gen. et sp. nov. as a new genus and species from the tropical Atlantic and two new Evoplosoma species, Evoplosoma claguei sp. nov. and Evoplosoma voratus sp. nov. from seamounts in the North Pacific. Hippasteria caribaea is reassigned to the genus Gilbertaster, which previously contained a single Pacific species. Our analysis supports Evoplosoma as a derived deep water lineage relative to its continental‐shelf, shallow water sister taxa. The genus Hippasteria contains approximately 15 widely distributed, but similar‐looking species, which occur in the northern and southern hemispheres. Except for Gilbertaster, at least one species in each genus has been observed or is inferred to prey on deep‐sea corals, suggesting that this lineage is important to the conservation of deep‐sea coral habitats. The Hippasterinae shares several morphological similarities with Circeaster and Calliaster, suggesting that they may be related. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 266–301.  相似文献   

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The genus Acanthonyx Latreille, 1828 (Majoidea, Epialtidae) contains 17 or 18 known species, depending on competing taxonomic views, that are widely distributed across the world. Morphologically, most species look superficially alike, and therefore, similar taxonomic concepts have been described under different names. Consequently, there is today a considerable list of synonyms, which further complicates the taxonomy of the genus Acanthonyx. In this study, we conducted a phylogeographical and phylogenetic analysis of populations of the genus Acanthonyx in the NE Atlantic, Mediterranean and Macaronesia using the mitochondrial cytochrome oxidase subunit I (COI) and the nuclear 28S rRNA loci. Our phylogenetic and phylogeographical results revealed that Acanthonyx lunulatus sensu lato is a complex of three distinct lineages: one corresponding to the previously described Acanthonyx brevifrons, another to A. lunulatus sensu stricto and a third to a yet undescribed group. Whereas our results confirms that A. brevifrons deserves the status of a species, as it can be easily distinguishable from A. lunulatus by a few morphological traits, we could not find any such traits suitable for the discrimination between A. lunulatus sensu stricto and the third lineage. Furthermore, the degree of COI divergence between this lineage and A. lunulatus is below average levels for Decapoda species. Yet, no shared haplotypes have been detected between them. The differences found in the nuclear gene (indels), together with the sympatric occurrence of the two forms, prompt for a more detailed analysis of this group. Overall, the results show that significant genetic differentiation between specimens with similar morphology occurs in the Epialtidae, thus reinforcing the importance of combining morphological and genetic tools to fully resolve the taxonomy of these decapods.  相似文献   

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Alyssum ovirense (Brassicaceae) is disjunctly distributed in the eastern Alps, predominantly occurring in the southern limestone Alps, but with one isolated population on the Hochschwab massif in the northern limestone Alps. The closely related rare and narrow endemic A. wulfenianum is restricted to gravel beds in a few rivers in the southern Alps draining the distribution area of A. ovirense. Applying molecular (amplified fragment length polymorphism fingerprinting and sequencing of plastid and nuclear DNA), karyological (flow cytometry and chromosome counts) and morphometric methods to a set of populations sampled throughout the distribution range, we evaluated the status of the population on the Hochschwab massif and the relationship between high‐elevation A. ovirense and low‐elevation A. wulfenianum. The population on Hochschwab massif is hexaploid, morphologically clearly divergent and grows in vegetation patches and dense alpine grasslands, whereas southern Alpine A. ovirense inhabits sparsely vegetated limestone screes. Molecular data show that the former represents a genetically isolated lineage which is formally described as A . neglectum sp. nov. All populations from the southern limestone Alps, including A. wulfenianum, are diploid. Although A. wulfenianum is genetically nested in A. ovirense, its morphological and ecological differentiation justifies recognition at the subspecific level. As A. wulfenianum has priority over A. ovirense, the correct names are A. wulfenianum subsp. wulfenianum and A. wulfenianum subsp. ovirense. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 486–505.  相似文献   

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We investigated the genetic diversity and phylogenetic placement of the butterflies in the genus Colotis and eight related pierid genera using sequence information from two mitochondrial and two nuclear genes. To establish the status of species, we initially barcoded 632 specimens representative of all genera and most species and subspecies in those genera. A subset was then selected for phylogenetic analysis where additional gene regions were sequenced: 16S rRNA (523 bp), EF‐1α (1126 bp) and wg (404 bp). DNA barcode results were largely congruent with the traditional classification of species in the Colotis group, but deep splits or lack of genetic divergence in some cases supported either species‐level differentiation or synonymy. Despite using information from four genes, the deeper nodes in our phylogeny were not strongly supported, and monophyly of the ‘Colotis group’ and the genera Colotis and Eronia could not be established. To preserve the monophyly of Colotis, we revive the genus Teracolus for three outlying species previously in Colotis (i.e. Colotis eris, Colotis subfasciatus and Colotis agoye), as well as the genus Afrodryas for Eronia leda. The position of Calopieris is unresolved although it appears to be well outside the molecular variation in Colotis (s.l.). A dispersal/vicariance analysis suggested that major diversification in Colotis (s.str.) occurred in Africa with subsequent dispersal to India and Madagascar.  相似文献   

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Xavier, R., Santos, A. M., Harris, D. J., Sezgin, M., Machado, M., Branco, M. (2012). Phylogenetic analysis of the north‐east Atlantic and Mediterranean species of the genus Stenosoma (Isopoda, Valvifera, Idoteidae). —Zoologica Scripta, 41, 386–399. The marine isopod genus Stenosoma is widespread in the northern hemisphere. However, 12 of its 14 known species are found within the Mediterranean basin and adjacent regions of the north‐east Atlantic and the Black Sea. Such a high level of diversity confined to a limited region of a much larger circumglobal distribution suggests that the Mediterranean region may have played a crucial role in the evolutionary history of this genus. In the present work, the phylogeny of the genus Stenosoma was investigated on the basis of DNA sequencing data from one nuclear (28SrRNA) and two mitochondrial (COI, ND4) gene fragments obtained for nine of 12 Atlantic–Mediterranean species. Divergence time estimates point to a Tethyan origin of Stenosoma and suggest that the speciation events from which stem most of the extant species took place well before the Messinian Salinity Crisis. Stenosoma spinosum and Stenosoma appendiculatum are the only exceptions, as they apparently arose within the Mediterranean during the Pleistocene. Phylogenetic reconstruction agrees with current taxonomic status of most species. However, Stenosoma capito clustered in two distinct and well‐supported clades, one composed of eastern Mediterranean and Black Sea specimens and the other by western Mediterranean and Atlantic ones. Such polyphyly suggests the existence of a previously unrecognized species, Stenosoma sp., which so far has been confounded with S. capito.  相似文献   

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The brown alga Lobophora (Dictyotales, Phaeophyceae) is an important macroalga in the North-eastern Atlantic archipelagos (i.e., Macaronesia). Notably in the Canaries it can dominate benthic assemblages. While the genus has been the subject of several ecological studies in the Canaries, no study has yet been conducted to assess species-level diversity of Lobophora in Macaronesia. We reassessed the diversity of Lobophora in Macaronesia, reporting the presence of seven species (L. caboverdeana sp. nov., L. canariensis, L. dagamae sp. nov., L. delicata, L. dispersa, L. littlerorum, and L. schneideri). Lobophora spp. from Macaronesia are morphologically and ecologically distinguishable. In the Canaries, L. schneideri dominates the photophilic assemblages from the intertidal to 20-30 m depth. Lobophora dagamae sp. nov. grows in less illuminated shallow habitats, and replaces L. schneideri from 30 to ~80 m. Lobophora canariensis also has a wide vertical distribution, from the intertidal to deep waters, while L. delicata, L. dispersa and L. littlerorum grow in shallow waters. The dominance of species with an upright habit versus prostrate or crustose species may be mediated by the pressure of herbivores. Four species have an amphi-Atlantic distribution: L. littlerorum, L. canariensis, L. delicata, and L. schneideri. Lobophora schneideri and L. delicata are furthermore distributed in the Mediterranean Sea. By sampling a pivotal region in the Atlantic, this study significantly improves our knowledge of Lobophora biogeography in the Atlantic Ocean. Macaronesia constitutes a species–poor region for Lobophora where no diversification events occurred, and a region of overlap between the Greater Caribbean and the Indo-Pacific.  相似文献   

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Moura, C. J., Cunha, M. R., Porteiro, F. M., Yesson, C. & Rogers, A. D. (2011) Evolution of Nemertesia hydroids (Cnidaria: Hydrozoa, Plumulariidae) from the shallow and deep waters of the NE Atlantic and Western Mediterranean. —Zoologica Scripta, 41, 79–96. Hydroid species from the genus Nemertesia develop some of the largest and most complex hydrozoan colonies. These colonies are abundant and ecologically important in both shallow and deep waters worldwide. Here, we analyse the systematics of most Nemertesia species from the NE Atlantic and Mediterranean using morphology and phylogenetic inferences of 16S rRNA haplotype data. Phylogeographical analysis revealed multiple movements of taxa to and from the Mediterranean after the Messinian salinity crisis through shallow and deep waters. The nominal species Nemertesia belini and Nemertesia antennina revealed multiple genetic lineages representing cryptic species diversity. Molecular phylogenetic evidence was supported by consistent phenotypic differences between lineages, and three and seven putative species were resolved within the N. belini and N. antennina complexes, respectively. Three putative species of the N. antennina complex found at different seamounts of Azores grouped in a clade clustered amongst the other four cryptic species present at neighbouring bathyal localities of the Gulf of Cadiz. These cryptic species, mostly from the deep sea, form a clade distantly related to the typical N. antennina from European coastal waters. Depth or environmental correlates of depth seem to influence the reproductive strategies of Nemertesia colonies and ultimately speciation. In particular, speciation of these hydroids must have been influenced by hydrography, habitat heterogeneity, isolation by distance and larval dispersal capacity. The deep sea is shown as an important environment in the generation and accumulation of lineages that may occasionally invade coastal waters in the NE Atlantic. Glacial cycles of cooling, along with changes in sea level, and eradication of some coastal faunas likely facilitated speciation and evolutionary transitions from deep to shallow waters.  相似文献   

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