Evolution of blindness in scolopendromorph centipedes (Chilopoda: Scolopendromorpha): insight from an expanded sampling of molecular data

Relative to its diversity (34 genera, 700 species), Scolopendromorpha has been undersampled in molecular phylogenetic analyses compared with the other chilopod orders. Previous analyses based on morphology have not resolved several key controversies in systematics and evolutionary morphology unambiguously. Here we apply new molecular and morphological data to scolopendromorph phylogenetics, with a focus on the evolution of blindness. The taxonomic sample includes 19 genera, many lacking previous molecular data, and diverse, cosmopolitan genera of Scolopendridae are sampled by multiple species. Phylogenetic analysis with Direct Optimization used 94 morphological characters and ca. 4.5 kb of sequence data from two nuclear (18S and 28S rRNA) and two mitochondrial (16S rRNA and COI) loci. A single most‐parsimonious cladogram selected after sensitivity analyses resolves Scolopendromorpha as monophyletic, and divides it into a blind clade of three families (Plutoniumidae, Cryptopidae, Scolopocryptopidae) and its ocellate sister group, Scolopendridae. Some species‐rich, cosmopolitan genera (Cormocephalus, Otostigmus, Scolopendra) in Scolopendridae are non‐monophyletic, and in several instances (e.g. New and Old World Scolopendra) relationships are more congruent with geographical distributions than with traditional classifications. The tribe Asanadini is particularly subject to parameter‐sensitivity, nesting in the combined analysis within Scolopendrini but as sister to all other Scolopendrinae for molecular data alone. The total‐evidence tree unambiguously optimizes trunk segmentation: a 23‐segmented trunk has a single origin in the blind clade. © The Willi Hennig Society 2011.     

Probing the Monophyly of the Sphaeropleales (Chlorophyceae) Using Data From Five Genes

Molecular phylogenetic analyses have had a major impact on the classification of the green algal class Chlorophyceae, corroborating some previous evolutionary hypotheses, but primarily promoting new interpretations of morphological evolution. One set of morphological traits that feature prominently in green algal systematics is the absolute orientation of the flagellar apparatus in motile cells, which correlates strongly with taxonomic classes and orders. The order Sphaeropleales includes diverse green algae sharing the directly opposite (DO) flagellar apparatus orientation of their biflagellate motile cells. However, algae across sphaeroplealean families differ in specific components of the DO flagellar apparatus, and molecular phylogenetic studies often have failed to provide strong support for the monophyly of the order. To test the monophyly of Sphaeropleales and of taxa with the DO flagellar apparatus, we conducted a molecular phylogenetic study of 16 accessions representing all known families and diverse affiliated lineages within the order, with data from four plastid genes (psaA, psaB, psbC, rbcL) and one nuclear ribosomal gene (18S). Although single‐gene analyses varied in topology and support values, analysis of combined data strongly supported a monophyletic Sphaeropleales. Our results also corroborated previous phylogenetic hypotheses that were based on chloroplast genome data from relatively few taxa. Specifically, our data resolved Volvocales, algae possessing predominantly biflagellate motile cells with clockwise (CW) flagellar orientation, as the monophyletic sister lineage to Sphaeropleales, and an alliance of Chaetopeltidales, Chaetophorales, and Oedogoniales, orders having multiflagellate motile cells with distinct flagellar orientations involving the DO and CW forms.     

Using 18S rDNA to resolve diaptomid copepod (Copepoda: Calanoida: Diaptomidae) phylogeny: an example with the North American genera

The phylogenetic relationships among the numerous genera of diaptomid copepods remain elusive due to difficulties in obtaining sufficient numbers of phylogenetically informative morphological characters for cladistic analysis. Molecular phylogenetic techniques offer high potential to resolve phylogenetic relationships in the absence of sufficient morphological characters because of the ease in which many characters can be unambiguously coded. I present the first molecular phylogeny for diaptomid copepod genera using 18S rDNA. Specifically, I test Light’s (1939) hypothesis regarding the interrelationships among the North American diaptomid genera. The 18S phylogeny is remarkably consistent with Light’s hypothesis. The endemic North American genera represent a monophyletic group exclusive of the non-endemic genera. Moreover, his hypothesized basal genus for the North America genera, Hesperodiaptomus, is the basal genus in this analysis. However, his Leptodiaptomus group is not reciprocally monophyletic with his Hesperodiaptomus group, but is rather a derived member of the latter group. Finally, the genus Mastigodiaptomus is found to be more closely allied with the non-endemic genera, as Light suggested. This phylogeny contributes heavily to the understanding of phylogenetic relationships among North American diaptomids and has large implications for the systematics of diaptomids in general. The use of 18S rDNA sequences in phylogenetic analyses of diaptomid copepods can be used to confirm the monophyly of recognized genera, the interrelationships among genera, and subsequent biogeographic interpretation of the family’s diversification. The use of molecular data, such as 18S rDNA sequences, to test phylogenetic hypotheses based on a very limited number of morphological characters will be a particularly useful approach to phylogenetic analysis in this system.     

Phylogeny,evolutionary morphology,and hemipenis descriptions of the Middle American jumping pitvipers (Serpentes: Crotalinae: Atropoides)

The jumping pitvipers, genus Atropoides, occur at low to middle elevations throughout Middle America. Recent molecular phylogenetic analyses have included all six species of Atropoides, but only two studies have found Atropoides to be monophyletic and questions persist about relationships within the A. nummifer complex. In this study, our phylogenetic analyses of morphological data provide strong support for the monophyly of Atropoides and recover relationships within the genus that are mostly congruent with those of recent molecular studies, further supporting the evolutionary and biogeographic hypotheses proposed in those studies. Our analyses find support for a sister relationship between A. picadoi and the other Atropoides species and an A. occiduus–A. indomitus clade sister to an A. nummifer–A. mexicanus–A. olmec clade. Within the A. nummifer complex, we find A. mexicanus and A. olmec to be sister species to the exclusion of A. nummifer. We include morphological synapomorphies to support each clade within Atropoides and describe and illustrate the hemipenes of each species. In addition, we discuss the importance of morphological phylogenetics and the functionality and limitations of hemipenial data in systematics.     

Chasing ghosts: the phylogeny of Amaurobioidinae ghost spiders (Araneae,Anyphaenidae)

The family Anyphaenidae, also known as ghost spiders, includes a diverse array of nocturnal cursorial spiders that actively hunt on vegetation. The family is mostly distributed in the Americas and has been traditionally divided into three subfamilies. The mostly tropical and North American Anyphaeninae and the Amaurobioidinae, primarily distributed in southern South America, hold the bulk of the diversity, while the Malenellininae includes a single Chilean species. Here, we use a combined morphological and molecular approach to infer the relationships of the subfamily Amaurobioidinae and examine the delimitation of contentious genera. The morphological characters include both genitalic and somatic morphology, whereas molecular data include four markers, two mitochondrial (COI, 16S) and two nuclear (28S, H3). All our analyses agree on the monophyly of Amaurobioidinae, Amaurobioidini, Gayennini, the genera Negayan, Amaurobioides, Josa, Araiya, Arachosia and Monapia, as well as the paraphyly of Anyphaeninae. The total evidence analysis supports the novel placement of Josa as the sister group of both tribes Amaurobioidini and Gayennini, most of the previously known intergeneric relationships within Gayennini, and a clade of Amaurobioidini with a projecting ocular area, including Aysenoides, Axyracrus, Amaurobioides and Aysenia. The sequence data solve the puzzling placement of Philisca puconensis, here transferred to Tomopisthes, and Tasata chiloensis, transferred to Oxysoma. The advantages of the total evidence phylogenetic approach and the evolution of the male copulatory organ are discussed.     

毛茛科分子系统发育研究进展

毛茛科(Ranunculaceae)在被子植物的系统演化中占有十分重要的地位,其系统位置和科下演化关系一直备受争议。近20多年的分子系统学研究表明,以往基于形态学的分类系统与分子系统学研究结果存在巨大差异。通过形态学性状界定的绝大多数亚科都没有得到分子系统学支持。此外,通过形态学确定的一些属如升麻属(Cimicifuga)、黄三七属(Souliea)、獐耳细辛属(Hepatica)、白头翁属(Pulsatilla)和水毛茛属(Batrachium)等,根据分子系统学研究均应予以归并。而分子系统学研究也确立了一些类群的属级地位,如露蕊乌头属(Gymnaconitum)等。以中国分布的毛茛科植物为例,通过以往分子系统学研究,共有10个属被归并,2个属新被确立。然而,毛茛科分子系统学研究对于科下许多类群之间的关系目前仍然没有得到很好的解决,如毛茛亚科和翠雀族等类群的系统发育关系仍需要进行深入研究后方能确定。该文对近年来国内外有关毛茛科的分子系统学研究进展进行了综述,并对该科尚存的一些问题和未来的研究方向进行了讨论。     

Refuting the six‐genus classification of Penaeus s.l. (Dendrobranchiata,Penaeidae): a combined analysis of mitochondrial and nuclear genes

Ma, K. Y., Chan, T. ‐Y & Chu, K. H. (2011). Refuting the six‐genus classification of Penaeus s.l. (Dendrobranchiata, Penaeidae): a combined analysis of mitochondrial and nuclear genes. —Zoologica Scripta, 40, 498–508. The taxonomic revision in 1997 of the shrimps formerly classified in Penaeus s.l. has been one of the most controversial issues on systematics of the decapods in recent years. Since Pérez Farfante & Kensley (Penaeoid and Sergestoid Shrimps and Prawns of the World, 1997) split this long‐accepted taxon into six genera, much debate has been devoted to their proposed new classification scheme; this has taken place because there are serious doubts whether the said scheme could reflect the evolutionary relationships among the 29 Penaeus s.l. species. Although these shrimps can be easily separated into several groups morphologically, whether these subdivisions are truly monophyletic and warrant a generic rank continues to be hotly debated among taxonomists. This study examined a total of 2425 bp sequences from three nuclear protein genes (enolase, phosphoenolpyruvate carboxykinase and sodium–potassium ATPase α‐subunit), and the mitochondrial 16S and 12S rRNA gene of 18 Penaeus s.l. shrimps and 13 other species in the family Penaeidae. Our phylogenetic analyses strongly support the monophyly of Penaeus s.l. and, concurring with previous studies that used the mitochondrial genes alone, the paraphyly of both Penaeus s.s. (sensu Pérez Farfante & Kensley, Penaeoid and Sergestoid Shrimps and Prawns of the World, 1997) and Melicertus, rendering them non‐natural groupings. Our study reveals two lineages: Penaeus s.s. + Fenneropenaeus + Litopenaeus + Farfantepenaeus and Melicertus + Marsupenaeus, which exhibit genetic divergences comparable with those among other penaeid genera. However, all the morphological characters, which are emphasized by Pérez Farfante and Kensley and used to separate Penaeus s.l., do not correlate with the grouping revealed by the present, perhaps decisive, phylogenetic result. Such disparity may arise from selection on the morphology of genitalia and convergent evolution. Our molecular data clearly refute the six‐genus classification, and we advocate the restoration of the old Penaeus genus (=Penaeus s.l.) definition which is the only classification scheme with both the morphological and the molecular data being in agreement.     

Three novel species of Stemphylium from Sinkiang, China: their morphological and molecular characterization

Three new species of Stemphylium were isolated from diseased leaves of Luffa cylindrica, Lycium chinense and Cucumis melo growing in the Sinkiang province of Northwest China. Stemphylium luffae, S. lycii and S. cucumis are described by morphological and molecular phylogenetic analyses. The principal morphological characteristics of these three species are congruent with those of Stemphylium. They are distinguished from morphologically similar Stemphylium species based on characteristics of their conidia and conidiophores. In order to establish the molecular phylogenetic status of these species, DNA loci including the internal transcribed spacer (ITS) nuclear rDNA region and the glyceraldehyde-3-phosphate dehydrogenase (gpd) genes were amplified and sequenced. Phylogenetic analyses using Maximum-Parsimony (MP) and Neighbor-Joining (NJ) were performed on the combined DNA sequences of ITS and gpd gene regions. Both morphological observations and molecular analyses support S. luffae, S. lycii and S. cucumis as three new taxa.     

Molecular phylogeny of Geoplaninae (Platyhelminthes) challenges current classification: proposal of taxonomic actions

Despite likely being the most diverse group within the Tricladida, the systematics of land planarians (Geoplanidae) has received minor attention. The most species‐rich ingroup, the subfamily Geoplaninae, is restricted to the Neotropics. The systematics of Geoplaninae remains uncertain. Unique features supporting the genera are scanty; moreover, parts of the known species have been poorly described, making comparative studies difficult. Likewise the evolutionary relationships among land planarians remain insufficiently understood. In the present study, a phylogenetic hypothesis for selected taxa of Geoplaninae based on the molecular data is presented and discussed in the light of morphological features. Our phylogenetic inference is based on the fragments of three nuclear regions (18S, 28S rDNA and EF‐1α) and a mitochondrial marker (cytochrome oxidase I) for which we considered three optimality criteria (parsimony, maximum likelihood and Bayesian inference). Although our data provide little support for most basal nodes, our phylogenetic trees show a number of well‐supported clades, unveiling morphologically homogeneous groups. According to these results, we propose to separate Geoplana into Barreirana (formerly considered a subgenus), Cratera gen. n., Imbira gen. n., Matuxia gen. n., Obama gen. n. and Paraba gen. n., emend the diagnoses of Barreirana, Geoplana, Notogynaphallia, Pasipha and Xerapoa and review the classification of the species within these genera. For Geoplana goetschi sensu Marcus, (1951), a new name is proposed.     

A molecular phylogeny of the tribe Aphidini (Insecta: Hemiptera: Aphididae) based on the mitochondrial tRNA/COII, 12S/16S and the nuclear EF1α genes

Abstract A phylogeny of the tribe Aphidini (Hemiptera: Aphididae) was reconstructed from three gene fragments: two mitochondrial regions, partial tRNA‐leucine + cytochrome oxidase II (tRNA/COII), partial 12S rRNA + tRNA‐valine + 16S rRNA (12S/16S) and one nuclear gene, the elongation factor‐1 alpha (EF1α). Bayesian phylogenetic (BP) analyses were performed on each individual dataset of tRNA/COII, 12S/16S and EF1α, and maximum parsimony (MP), Bremer support test, maximum likelihood (ML) and BP analysis were performed on the combined dataset. After comparing our molecular phylogenetic results with the classic classification based on morphological and ecological data, we analysed three main issues: the monophyletic relationships among tribes and subtribes, the validities of the latest taxonomic positions of genera and species and the status of certain Aphis species groups. Our results indicate that 36 of the species analysed, with the exception of Cryptosiphum artemisiae, are clustered within the clade of Aphidini. Also, the 28 species representative of the subtribe Aphidina were separated from the eight species representative of Rhopalosiphina; each monophyletic subtribe was supported by significant P‐values in the combined analysis. According to our results, Cryptosiphum should be moved to Macrosiphini because it is more closely related to the genera Lipaphis and Brevicoryne. The genus Toxoptera was recovered as non‐monophyletic. In Rhopalosiphina, three genera, Hyalopterus, Rhopalosiphum and Schizaphis, were relatively closer to each other than to the genus Melanaphis. In the relationships between species‐groups among Aphis, most species were separated into two main lineages; the fabae group seemed to be more closely related to the spiraecola and craccivora group rather than to the gossypii group.     

Combined phylogenetic analysis of the subclass Marchantiidae (Marchantiophyta): towards a robustly diagnosed classification

The most extensive combined phylogenetic analyses of the subclass Marchantiidae yet undertaken was conducted on the basis of morphological and molecular data. The morphological data comprised 126 characters and 56 species. Taxonomic sampling included 35 ingroup species with all genera and orders of Marchantiidae sampled, and 21 outgroup species with two genera of Blasiidae (Marchantiopsida), 15 species of Jungermanniopsida (the three subclasses represented) and the three genera of Haplomitriopsida. Takakia ceratophylla (Bryophyta) was employed to root the trees. Character sampling involved 92 gametophytic and 34 sporophytic traits, supplemented with ten continuous characters. Molecular data included 11 molecular markers: one nuclear ribosomal (26S), three mitochondrial genes (nad1, nad5, rps3) and seven chloroplast regions (atpB, psbT‐psbH, rbcL, ITS, rpoC1, rps4, psbA). Searches were performed under extended implied weighting, weighting the character blocks against the average homoplasy. Clade stability was assessed across three additional weighting schemes (implied weighting corrected for missing entries, standard implied weighting and equal weighting) in three datasets (molecular, morphological and combined). The contribution from different biological phases regarding node recovery and diagnosis was evaluated. Our results agree with many of the previous studies but cast doubt on some relationships, mainly at the family and interfamily level. The combined analyses underlined the fact that, by combining data, taxonomic enhancements could be achieved regarding taxon delimitation and quality of diagnosis. Support values for many clades of previous molecular studies were improved by the addition of morphological data. The long‐held assumption that morphology may render spurious or low‐quality results in this taxonomic group is challenged. The morphological trends previously proposed are re‐evaluated in light of the new phylogenetic scheme.     

Phylogenetic relationships of Microdontinae (Diptera: Syrphidae) based on molecular and morphological characters

The intrasubfamilial classification of Microdontinae Rondani (Diptera: Syrphidae) has been a challenge: until recently more than 300 out of more than 400 valid species names were classified in Microdon Meigen. We present phylogenetic analyses of molecular and morphological characters (both separate and combined) of Microdontinae. The morphological dataset contains 174 characters, scored for 189 taxa (9 outgroup), representing all 43 presently recognized genera and several subgenera and species groups. The molecular dataset, representing 90 ingroup species of 28 genera, comprises sequences of five partitions in total from the mitochondrial gene COI and the nuclear ribosomal genes 18S and 28S. We test the sister‐group relationship of Spheginobaccha with the other Microdontinae, attempt to elucidate phylogenetic relationships within the Microdontinae and discuss uncertainties in the classification of Microdontinae. Trees based on molecular characters alone are poorly resolved, but combined data are better resolved. Support for many deeper nodes is low, and placement of such nodes differs between parsimony and Bayesian analyses. However, Spheginobaccha is recovered as highly supported sister group in both. Both analyses agree on the early branching of Mixogaster, Schizoceratomyia, Afromicrodon and Paramicrodon. The taxonomical rank in relation to the other Syrphidae is discussed briefly. An additional analysis based on morphological characters only, including all 189 taxa, used implied weighting. A range of weighting strengths (k‐values) is applied, chosen such that values of character fit of the resulting trees are divided into regular intervals. Results of this analysis are used for discussing the phylogenetic relationships of genera unrepresented in the molecular dataset.     

Combined molecular and morphological evidence on the phylogeny of the earliest lepidopteran lineages

Agreement among recent morphological and molecular phylogenetic analyses has strengthened estimates of the relationships among the earliest lineages of the holometabolan order Lepidoptera. For a few major groups, evidence for monophyly and basal relationships remains relatively weak or contradictory — chiefly within the clades of basal Glossata and Heteroneura. Here we assess the support for these controversial areas of lepidopteran classification through molecular systematic investigation of 18S rDNA sequence variation. Parsimony and maximum likelihood analyses are presented for 1379 alignable sites of 18S. These data are then combined with 61 morphological features scored for major lineages of basal Glossata and Heteroneura. Our 18S rDNA data support recent hypotheses for the placement of Micropterigidae and Agathiphagidae as the basal-most lineages of Lepidoptera, and support the monophyly of the groups Neolepidoptera and Exoporia. 18S data alone are shown to be insufficient for resolving the monophyly and relationships of the Glossata, and for specifying relationships above the Neolepidoptera. Combination of the 18S data with published morphological ground-plan scorings improves overall support for the morphology-based hypothesis for basal glossatans, but phylogenetic resolution among published alternatives for the basal Heteroneura remains a major question for lepidopteran systematics.     

Molecular phylogeny and taxonomy of the genus Chaetophora (Chlorophyceae,Chlorophyta), including descriptions of Chaetophoropsis aershanensis gen. et sp. nov.

The broadly defined genus Chaetophora consisted of species with minute, uniseriate branching filaments enveloped in soft or firm mucilage forming macroscopic growths that are spherical, hemispherical, and tubercular or arbuscular, growing epiphytically on freshwater aquatic plants and other submerged surfaces in standing or fast‐flowing water. Recent molecular analyses clearly showed that this genus was polyphyletic. In this study, eight strains of Chaetophora and three strains of Stigeoclonium were identified and successfully cultured. In combination with the morphological data, a concatenated data set of four markers (18S + 5.8S + ITS2+ partial 28S rDNA) was also used to determine their taxonomic relationships and phylogenetic positions. The molecular analysis resolved the broadly defined Chaetophora to at least two genera. Species with a globose thallus of genus Chaetophora formed a separate monophyletic clade, which clearly separated from, a type of lobe‐form Chaetophora species. Therefore, we propose to erect a new genus, Chaetophoropsis, which includes all globose species of the Chaetophora. Chaetophoropsis aershanensis was determined to be a new species, based on its special characteristic of profuse long rhizoids. Stigeoclonium polyrhizum, as the closest relative to Chaetophoropsis, revealed its distant relationships to other species of Stigeoclonium. A globose thallus with a thick, soft mucilage matrix, and special rhizoidal branches lent further support to the placement of S. polyrhizum in the genus Chaetophoropsis and had the closest relationship to C. aershanensis. Taxonomic diversity was proven by distinctive morphological differences and by phylogenetic divergence in the broadly defined Chaetophora identified herein.     

Phylogenetic and systematic study of Korean <Emphasis Type="Italic">Orius</Emphasis> species (Heteroptera: Anthocoridae) on the basis of molecular and morphological data

A phylogenetic and systematic study of Orius species (Heteroptera: Anthocoridae) from Korea has been conducted using both morphological and molecular characters. Thirty morphological character states were coded for 10 strains of 9 species. Five molecular markers, partial cytochrome c oxidase I (COI), cytochrome b (CytB), 16S rRNA (16S), 18S rRNA (18S), and 28S rRNA (28S), from mitochondrial and nuclear genes, were tested. Phylogenetic analyses based on molecular data were conducted by minimum evolution, maximum parsimony, maximum likelihood, and Bayesian phylogenetic (BP) analyses. Analysis of morphological data was performed using the parsimony programs NONA, and the combined dataset of morphological and molecular data was analyzed using BP analyses. The results of this study indicate that use of COI and CytB enabled relatively effective identification of species, whereas the sequences of 16S, 18S and 28S did not enable identification of closely related species such as Orius minutus and O. strigicollis. We discuss the usefulness of the five molecular markers for determining phylogenetic relationships and identifying the species.     

Molecular and morphological characterization of a poorly known marine ciliate, Myoschiston duplicatum precht 1935: implications for phylogenetic relationships between three morphologically similar genera -- Zoothamnium, Myoschiston, and Zoothamnopsis (Ciliophora, Peritrichia, Zoothamniidae)

We studied the morphology and molecular phylogeny of Myoschiston duplicatum, a peritrich ciliate that has been recorded as an epibiont of crustaceans, but which we also identified on marine algae from Korea. The important morphological characteristics revealed by silver staining of Myoschiston species have not been described because they are rarely collected. Using morphological methods, we redescribed the type species of the genus, Myoschiston duplicatum, and provided an improved diagnosis of Myoschiston. In addition, the coding regions for nuclear small subunit (SSU) rRNA and internal transcribed spacer 1‐5.8S‐internal transcribed spacer 2 sequences were sequenced. Phylogenetic analyses that included available SSU rDNA sequences of peritrichs from GenBank strongly supported a position of M. duplicatum within the family Zoothamniidae. In addition, phylogenetic analyses were performed with single datasets (ITS1‐5.8S‐ITS2) and combined datasets (SSU rDNA + ITS1‐5.8S‐ITS2) to explore further the phylogenetic relationship in the family Zoothamniidae between the three morphologically similar genera—Zoothamnium, Myoschiston, and Zoothamnopsis.     

Reconciling classical and molecular phylogenies in the stichotrichines (Ciliophora, Spirotrichea), including new sequences from some rare species

We performed a comparative morphological and molecular study on oxytrichid and urostylid stichotrichs (=part of the former hypotrichs). Included are new small subunit (18S) ribosomal RNA (rRNA) gene sequences from five rare oxytrichids (Gonostomum namibiense, Cyrtohymena citrina, Hemiurosoma terricola, Onychodromopsis flexilis, Orthoamphisiella breviseries) and published sequences, based on cultures provided by the senior author, of two key stichotrichid genera, viz., Gastrostyla and Engelmanniella. These and other sequences, altogether 27 species representing 23 genera, were used to analyze how 18S rRNA-based phylogenetic trees can be reconciled with the morphological and ontogenetical data. In 18S rRNA trees, the oligotrichine family Halteriidae invariably clusters within the oxytrichid clade, usually near Oxytricha granulifera, type species of the genus. This position is hardly supported by morphological and ecological evidence and, especially, it contradicts the current ontogenetic findings; possibly, it is an artifact caused by taxa undersampling and/or special molecular evolutionary events. In contrast, most morphological and DNA sequence data of the stichotrichs can be harmonized with the CEUU (Convergent Evolution of Urostylids and Uroleptids) hypothesis which suggests that the urostylid midventral pattern evolved from an oxytrichine ancestor, developing a second time within the Oxytrichidae. The systematic position of one of the two key genera could be clarified with the 18S rRNA sequences: Gastrostyla is a stylonychine oxytrichid. Based on the molecular data and a reassessment of ontogenesis, a new genus, Styxophrya nov. gen., is established for Onychodromus quadricornutus Foissner, Schlegel & Prescott, 1987.     

Molecular relationships of gammaridean amphipods from Arctic sea ice

The information on the biology and ecology of the Arctic sea ice-associated amphipods (Apherusa glacialis, Gammarus wilkitzkii, Onisimus glacialis, and O. nanseni) has increased, but their molecular taxonomic information still remains undisclosed. In the present study, we investigated long-range DNA sequences spanning 18S to 28S rDNA of these four sea ice-associated amphipods and analyzed their genetic relationships with other amphipod taxa. Variations of rDNA within the individuals of the same species were not detected. Phylogenetic analyses showed that each ice amphipod was separated, forming clusters with other conspecifics. Pairwise comparisons led to similar phylogenetic results, showing that the molecular taxonomy of the ice amphipods was in accordance with morphological systematics. In addition, these findings suggest that all four amphipods have little genetic variation compared with their morphologically defined conspecifics from temperate regions. Based on DNA taxonomy, G. wilkitzkii was supported as a species in good standing, refuting a recent synonymization with Gammarus duebeni. Considerably low genetic divergences of O. glacialis and O. nanseni in 18S, ITS, and 28S rDNA suggest the presence of population distinctions within species.     

Revisiting the North American freshwater mussel genus Quadrula sensu lato (Bivalvia Unionidae): Phylogeny,taxonomy and species delineation

Freshwater mussels (Bivalvia, Unionidae) have suffered strong declines over the last century. High morphological plasticity of Unionidae causes disturbances in their systematics and taxonomy, hampering conservation efforts. Species that have historically been placed under the North American genus Quadrula have suffered from numerous taxonomic and species delineation problems since its inception. Four genera are presently recognized within Quadrula sensu lato, that is, Cyclonaias, Quadrula, Theliderma and Tritogonia, but their phylogenetic basis remains incompletely tested. In the present study, we reconstructed several two‐marker (mtDNA cytochrome c oxidase subunit I—COI and NADH dehydrogenase subunit 1—ND1) phylogenies with newly collected specimens and all previously available sequences covering most species within this group. We then delineated the species within the group using an integrative approach with the application of molecular statistical methods, morphometric (Fourier Shape) analyses and geographic distribution data. Four clades corresponding to these genera were consistently recovered in all phylogenies. To validate the generic status of these clades, molecular analyses were complemented with morphological, anatomical and ecological data compiled from the literature. Several revisions are here proposed to the current systematics and taxonomy of these genera, including the synonymization of Cyclonaias asperata under Cyclonaias kieneriana; the inclusion of Quadrula apiculata and Quadrula rumphiana under Quadrula quadrula; the placement of Quadrula nobilis under Tritogonia; and finally the separation of the Mobile River basin populations of Theliderma metanevra as a new species, that is, Theliderma johnsoni n. sp. The conservation implications of the proposed changes are then discussed.     

Systematics of the snake genera Stenophis and Lycodryas from Madagascar and the Comoros

Nagy, Z. T., Glaw, F. & Vences, M. (2010) Systematics of the snake genera Stenophis and Lycodryas from Madagascar and the Comoros. —Zoologica Scripta, 39, 426–435. Arboreal snakes belonging to the pseudoxyrhophiine genus Stenophis inhabit Madagascar but despite their spectacular appearance, surprisingly little is known about their natural history and systematics. Nonetheless, a close phylogenetic affinity of the genera Stenophis and Lycodryas (the latter genus currently includes a single species from the Comoros) has been hypothesized. Based on recent molecular genetic data, however, the monophyly of Stenophis was challenged. This study aimed at a systematic analysis and taxonomic revision of the genera Stenophis and Lycodryas. On the basis of new molecular genetic and morphological data and analyses, we propose to accommodate these snakes in three monophyletic genera: Lycodryas, Phisalixella and Parastenophis, and to consider Stenophis as a junior synonym of Lycodryas. In the new generic arrangement, the genera can also be well distinguished by morphological characters. On the specific level, Phisalixella tulearensis is resurrected and indications of further, undescribed taxa are revealed.