The effects of mode of development on phylogeography and population structure of North Atlantic Crepidula (Gastropoda: Calyptraeidae)

The mode of development of marine invertebrates is thought to influence levels of population structure and the location of species range endpoints via differences in dispersal ability. To examine these effects, populations of three sympatric clades of sedentary, marine gastropods in the genus Crepidula were sampled along the Atlantic and Gulf coasts of North America. A haplotype tree was constructed for each clade based on 640 bp sequences of mitochondrial cytochrome oxidase c subunit I. Examination of the tree topology, and AMOVA analysis show that species with direct development (those hatching as benthic juveniles) have higher levels of population structure than do species with planktonic development. Both species in the direct-developing C. convexa clade have high levels of geographical differentiation, with most populations representing a discrete clade of haplotypes. The planktotrophic species C. fornicata contains two major haplotype clades, both of which include samples from throughout the Atlantic coast. In this species there is no geographical differentiation among haplotypes but AMOVA analysis detects a small but statistically significant level of geographical structure. The population structure within the C. plana species complex appears also to vary with mode of development: C. atrasolea, a direct-developing species, has higher levels of population structure than does C. depressa, a sympatric planktotrophic species. The coincident occurrence of range endpoints and genetic breaks along the east coast of Florida in both direct-developing species and species with planktonic development indicates that this biogeographic break is not due to development-specific mechanisms such as hydrographic effects on larval recruitment.     

The utility of morphological characters in gastropod phylogenetics: an example from the Calyptraeidae

Organismal taxonomy is often based on a single or a small number of morphological characters. When they are morphologically simple or known to be plastic, we may not have great confidence in the taxonomic conclusions of analyses based on these characters. For example, calyptraeid gastropod shells are well known for their simplicity and plasticity, and appear to be subject to frequent evolutionary convergences, but are nevertheless the basis for calyptraeid taxonomy. In a case like this, knowing how the pattern of relationships inferred from morphological features used in traditional taxonomy compares to the patterns of relationships inferred from other morphological characters or DNA sequence data would be useful. In this paper, I examine the relative utility of traditional taxonomic characters (shell characters), anatomical characters and molecular characters for reconstructing the phylogeny of calyptraeid gastropods. The results of an ILD test and comparisons of the recovered tree topologies suggest that there is conflict between the DNA sequence data and the morphological data. Very few of the nodes recovered by the morphological data were recovered by any other dataset. Despite this conflict, the inclusion of morphological data increased the resolution and support of nodes in the topology recovered from a combined dataset. The RIs and CIs of the morphological data on the best estimate topology were not any worse than these indices for the other datasets. This analysis demonstrates that although analyses can be misled by these convergences if morphological characters are used alone, these characters contribute significantly to the combined dataset.  © 2003 The Linnean Society of London . Biological Journal of the Linnean Society , 2003, 78 , 541–593.     

Multilocus phylogeny of a cryptic radiation of Afrotropical long-fingered bats (Chiroptera,Miniopteridae)

The Old World bat family Miniopteridae comprises only the genus Miniopterus, which includes 20 currently recognized species from the Afrotropical realm and 15 species from Eurasia and Australasia. Since 2003, the number of recognized Miniopterus species has grown from 19 to 35, with most newly described species endemic to Madagascar and the Comoros Archipelago. We investigated genetic variation, phylogenetic relationships and clade membership in Miniopterus focusing on Afrotropical taxa. We generated mitochondrial cytochrome-b (cyt-b) and nuclear intron data (five genes) from 352 vouchered individuals collected at 78 georeferenced localities. Including 99 additional mitochondrial sequences from GenBank, we analysed a total of 25 recognized species. Mitochondrial genetic distances among cyt-b-supported clades averaged 9.3%, representing as many as five undescribed species. Multilocus coalescent delimitation strongly supported the genetic isolation of eight of nine tested unnamed clades. A large number of sampled clades in sub-Saharan Africa are distributed wholly or partly in East Africa (nine of 13 clades), suggesting that Miniopterus diversity has been grossly underestimated. Although 25 of 27 cyt-b and 23 of 25 nuclear gene tree lineages from the Afrotropics were strongly supported as monophyletic, a majority of deep nodes were poorly resolved in phylogenetic analyses. Long terminal branches subtending short backbone internodes in the phylogenetic analyses suggest a rapid radiation model of diversification. This hypothesis needs to be tested using more phylogenetically informative data.     

Molecular phylogeny and systematics of Australian and East Timorese Stenothyridae (Caenogastropoda: Truncatelloidea)

The Australian and East Timorese species belonging to the truncatelloid family Stenothyridae are revised using molecular data and morphological characters from the shell, operculum, radula and external and reproductive anatomy. The Australian species Stenothyra australis is redescribed and two previously recognised subspecies are shown to be synonyms. The New Guinean species Stenothyra paludicola van Benthem Jutting, 1963 Benthem Jutting, W.S.S. van (1963) Non-marine Mollusca of West New Guinea. Part I: Mollusca from fresh and brackish waters. Nova Guinea, Zoology 20, 409–521. [Google Scholar] is redescribed and recorded from the Torres Strait region of northern Australia, and two new subspecies of S. paludicola are described from the Northern Territory and East Timor; S. paludicola topendensis n. subsp. and S. paludicola timorensis n. subsp. respectively. Stenothyra gelasinosa n. sp. is described from Australia, comprising three allopatric subspecies; S. gelasinosa gelasinosa n. sp. and n. subsp. from the eastern seaboard, S. gelasinosa phrixa n. subsp. from northern Australia and S. gelasinosa apiosa n. subsp. from the Pilbara region of Western Australia. Stenothyra frustillum is considered a nomen dubium. Molecular phylogenetic analysis of these taxa and other Asian stenothyrids supports these systematic decisions and provides a preliminary interpretation of relationships within Stenothyridae.     

Speciation in ancient cryptic species complexes: evidence from the molecular phylogeny of Brachionus plicatilis (Rotifera)

Continental lake-dwelling zooplanktonic organisms have long been considered cosmopolitan species with little geographic variation in spite of the isolation of their habitats. Evidence of morphological cohesiveness and high dispersal capabilities support this interpretation. However, this view has been challenged recently as many such species have been shown either to comprise cryptic species complexes or to exhibit marked population genetic differentiation and strong phylogeographic structuring at a regional scale. Here we investigate the molecular phylogeny of the cosmopolitan passively dispersing rotifer Brachionus plicatilis (Rotifera: Monogononta) species complex using nucleotide sequence variation from both nuclear (ribosomal internal transcribed spacer 1, ITS1) and mitochondrial (cytochrome c oxidase subunit I, COI) genes. Analysis of rotifer resting eggs from 27 salt lakes in the Iberian Peninsula plus lakes from four continents revealed nine genetically divergent lineages. The high level of sequence divergence, absence of hybridization, and extensive sympatry observed support the specific status of these lineages. Sequence divergence estimates indicate that the B. plicatilis complex began diversifying many millions of years ago, yet has showed relatively high levels of morphological stasis. We discuss these results in relation to the ecology and genetics of aquatic invertebrates possessing dispersive resting propagules and address the apparent contradiction between zooplanktonic population structure and their morphological stasis.     

New insights into tateid gastropods and their radiation on Fiji based on anatomical and molecular methods (Caenogastropoda: Truncatelloidea)

The South Pacific archipelago of Fiji is characterized by a predominantly Indo‐Malesian flora and fauna. We provide a first systematic study on Fiji's tateid gastropods – previously classified as Hydrobiidae – describing 18 new species, combining morphological, anatomical, and molecular data. The molecular phylogeny of tateid gastropods based on 16S rRNA and cytochrome c oxidase subunit I (COI) showed that the species from Fiji were closer related to New Zealand than to Australian or New Caledonian taxa, which is rather exceptional. Performing an ancestral range reconstruction we inferred the colonization history across the two main islands. The radiation had its origin in southern Viti Levu, with a subsequent dispersal over the western and central parts of the island. The chronology of the radiation over eastern Viti Levu and Vanua Levu remained unresolved because of incomplete lineage sorting, a phenomenon typical for young radiations. © 2014 The Linnean Society of London     

Integrative taxonomy reveals cryptic Amazonian species of Pristimantis (Anura: Strabomantidae)

Hypotheses on the taxonomic status of two Bolivian Pristimantis with taxonomic problems are assessed by an integrative taxonomic approach that integrates three independent lines of evidence: external morphology, prezygotic reproductive barriers (advertisement calls) and reciprocal monophyly (phylogenetic analyses of partial 16S mtDNA sequences). Central Andean Bolivian populations previously assigned to either P. peruvianus or P. dundeei, and lowland Amazonian populations from southern Peru and northern Bolivia previously considered P. peruvianus do not correspond to these species. Indeed, multivariate analyses of qualitative and quantitative morphological and bioacoustic characters, and phylogenetic analyses support the hypothesis that they represent different, previously unknown, cryptic lineages. They are herein described as new species. The former is a sibling species of P. fenestratus that inhabits the Amazonian and semideciduous forests of the Andean foothills in central Bolivia. The latter is sibling to the Andean species P. danae and is parapatric to it in the Amazonian lowland forests and adjacent foothills of northern Bolivia, southern Peru and adjacent Brazil. Most species of Neotropical frogs, and especially Pristimantis, have been described by using external qualitative morphological characters only. An extended integrative taxonomic approach, as exemplified herein, may lead to the discovery of many other cryptic and sibling lineages that would increase the species numbers of tropical areas. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 97–122.     

DNA taxonomy, phylogeny and Pleistocene diversification of the Cicindela hybrida species group (Coleoptera: Cicindelidae)

Species delimitation is complicated where morphological variation is continuous or poorly subdivided, but for taxonomic convenience it is common practice to separate and name geographical groups to capture this variation. DNA-based approaches may be used to test if these groups in fact represent historically divided, discrete species entities. The Cicindela hybrida complex (Coleoptera: Cicindelidae) is an assemblage of up to seven morphologically recognized species and 15 subspecies with wide distribution in the Palaearctic region. We sequenced a discontinuous segment of 1899 bp of mtDNA including three regions (coxI, rrnL+trnL2+nad1, cob) for a total of 99 specimens from 36 sampling localities across Europe, revealing 48 haplotypes. Four major clades could be identified corresponding to geographical groups from central Iberia, Ukraine, central Europe, and a band from the Atlantic Iberian coast to northern Europe. Taking into account further subdivisions within these clades, four of the six named species included in the analysis were recognizable by applying various procedures for species delimitation. Age estimates from calibrated molecular clocks date the diversification of the hybrida group within the past 2 million years (Myr), and the separation of the northern clade within 0.4 Myr. Nested clade analysis revealed the rapid range expansion of the northern group consistent with postglacial dispersal, but we did not find support for specific source population(s) in the postulated southern refugia. The evolutionary framework based on mtDNA sequences is shown to identify species entities as discrete clusters of closely related sequences and provides an objective system for delineating and recognizing hierarchically structured groups. In the case of the C. hybrida complex, these groups largely coincided with those established from morphology. The study adds further support to the utility of mtDNA-based sequence profiles (the 'DNA taxonomy') as a rapid and objective synthesis of evolutionary diversity and as reference system for communication.     

Novel microsatellite markers for an endangered freshwater snail,Heleobia atacamensis (Caenogastropoda: Cochliopidae), from the Atacama Saltpan

ABSTRACT

The minute freshwater gastropod Heleobia atacamensis is only known from its type locality Tilopozo, located at the southern end of the Atacama Saltpan, Antofagasta Region, Chile. It is classified as Critically Endangered by the national agency, Ministerio del Medio Ambiente de Chile, due to its restricted distribution. For the first time, we have isolated and evaluated 65 microsatellite markers in 42 specimens of H. atacamensis, successfully characterising 11 as polymorphic. Cross-amplification testing was successful in three other species of the genus. As a result, the development and characterisation of these markers could be useful in future genetic studies of H. atacamensis and its congeners, regarding population structuring, dispersal patterns and recent demographic history. Furthermore, this information will also be significant to undertake conservation efforts in this endangered species, since its environment is highly threatened by lithium mining activities and a global water crisis.     

Spiders of the families Theridiidae, Tetragnathidae and Araneidae (Arachnida: Araneae) from Aldabra atoll

A total of 36 spider species of the families Theridiidae, Tetragnathidae and Araneidae are recorded from Aldabra atoll. Of these, 26 are described as new, together with one new subspecies. The taxonomy of the new species is discussed and, for comparative purposes, five other species not from Aldabra are illustrated. One new synonymy is established. Records for each species are given with, in some cases, notes on biology. The possible biological significance of the egg sac strings found in some species is considered. Finally, the biogeographical affinities of the Aldabra species are briefly discussed.     

Isolation and characterization of highly polymorphic microsatellite markers from the marine invasive species Crepidula fornicata (Gastropoda: Calyptraeidae)

Many marine organisms have pelagic larvae and these are often important agents of dispersal and establishment of exotic species. The larval phase and the hermaphroditic reproductive system of the invasive marine gastropod Crepidula fornicata are crucial in determining the success of this species along the European coasts. To analyse these factors, we developed seven microsatellite loci specific to C. fornicata. On the same set of individuals, the microsatellite loci exhibited a greater level of polymorphism than previously studied allozyme markers and, thus, will permit fine‐scale analysis and larval pool studies.     

Data on molecular taxonomy and genetic diversification of the European Hermit beetles, a species complex of endangered insects (Coleoptera: Scarabaeidae, Cetoniinae, Osmoderma)

A molecular analysis was carried out on the European hermit beetles (the Osmoderma eremita species complex) to explore their genetic diversification and the robustness of previous morphologically based taxonomic arrangements. Complete sequences of mtDNA cytochrome C oxidase I gene were obtained from 26 individuals. Mean levels of interspecific sequence divergence ranged from 0.044 to 0.186. The results indicate a clear-cut distinction between two clades. The first one includes the W-European O. eremita Scopoli 1763 ; and the two Italian endemic taxa Osmoderma italicum Sparacio, 2000 and Osmoderma cristinae Sparacio, 1994 ; from southern peninsular Italy and Sicily, respectively. The second one includes the widespread E-European Osmoderma barnabita ; and the southern Balcanic Osmoderma lassallei Baraud and Tauzin, 1991 from Greece and European Turkey. Within the two clades, molecular and morphological data well support a specific rank for O. lassallei and O. barnabita on one side, and for O. eremita and O. cristinae on the other side, while the taxonomic position of O. italicum , more closely related to O. eremita , is still uncertain. Current geographical distribution, interspecific genetic diversification, and very low levels of intraspecific genetic divergence in western European populations of O. eremita sensu stricto are hypothesized to be the result of multiple speciation events (mainly occurred in refugial forest areas of the Italian and Balkan peninsulas and Sicily before and during the Pleistocene glacial peaks), followed by fast post-glacial northward and westward expansion of some species.     

Taxonomy and phylogeny of Lineus torquatus and allies (Nemertea,Lineidae) with descriptions of a new genus and a new cryptic species

The heteronemertean genus Lineus Sowerby, 1806 has been badly in need of revision because of its apparent non-monophyly. In this paper, we focus on Lineus torquatus Coe, 1901, one of the heteronemertean species that occur commonly in waters around the North Pacific, as well as a few other allied species distributed in the western North Pacific, including Lineus alborostratus Takakura, 1898 and Cerebratulus montgomeryi Coe, 1901. Based on phylogenetic analyses using 16S, COI, 28S, 18S, and H3 gene and ITS sequences, we detected a well-supported clade comprised of heteronemerteans with a frontal white band on the head, to which we add Kulikovia gen. nov. This genus is nested within a more comprehensive, highly supported clade, here named the Siphonenteron-clade, which contains Tenuilineus bicolour (Verrill, 1892), Lineus flavescens Coe, 1905, Siphonenteron bilineatum (Renier, 1804), S. cf. bilineatum, Lineus cf. caputornatus, and Lineus sp. from Guam. Our analyses confirmed the presence of a cryptic species of what was formerly known as the cherry-red and reddish forms of Lineus torquatus, herein described as Kulikovia manchenkoi sp. nov. based on some external characters, internal morphology, and the four genetic markers (COI, 16S, H3, and ITS). In contrast to the species pair K. torquata–K. manchenkoi, the reddish form of K. alborostrata does not differ genetically from the typical form of this species. The significance of the external and internal characters for distinguishing cryptic species is discussed.

http://zoobank.org/urn:lsid:zoobank.org:pub:9BECBC60-9C82-48EC-AD36-FC564D82A5BChttp://zoobank.org/urn:lsid:zoobank.org:act:D02B2339-4F65-4517-9B13-DD4AAB0C55C5http://zoobank.org/urn:lsid:zoobank.org:act:8D239B62-E655-4721-90F0-A4944DD8A3C7     

Systematics of the Neotropical caddisfly genus Notidobiella Schmid (Trichoptera, Sericostomatidae), with the description of 3 new species

Three new species of Notidobiella Schmid (Insecta: Trichoptera) are described from South America: Notidobiella amazonianasp. n. (Brazil), Notidobiella brasilianasp. n. (Brazil), and Notidobiella ecuadorensissp. n. (Ecuador). In addition, the 3 previously described species in the genus, Notidobiella chacayana Schmid, Notidobiella inermis Flint, and Notidobiella parallelipipeda Schmid, all endemic to southern Chile, are redescribed and illustrated, including the females of each species for the first time, and a key to males of the species in the genus is provided. The occurrence of Notidobiella in Brazil and Ecuador represents a significant extension of the range of the genus beyond southern Chile where it previously was thought to be endemic. The biogeography of Sericostomatidae and other austral South American Trichoptera is reviewed. The presence of the family in South America may not be part of a "transantarctic" exchange, but instead may represent an earlier occurence in the region. The distribution of Notidobiella in tropical South America likely represents recent dispersal from southern South America to the north.     

基因组学时代的真菌分类学:机遇与挑战

真菌物种的形态特征有限,加之形态滞后和形态可塑性,仅靠外部形态、内部结构及生理生化指标,很难把握真菌的系统亲缘。应用DNA测序、基因组测序、比较基因组学及生物信息学等技术,研究人员可以快速识别真菌演化中出现的数量众多的单系支系,为建立各分类等级的新分类单元提供有力证据,为真菌分类学研究带来了新的希望和活力。自2000年以来,在真菌界至少发表了1新亚界、4新门、7新亚门、19新纲、9新亚纲、40余新目等高级分类单元。近3年来,我国发表了20余个真菌新属,其中绝大多数属的建立都有分子证据支持。可以预见,大量的新种、新属、新科乃至更高级分类单元将会在今后10年内持续发现和建立。这必将大大促进真菌分类学的发展,完善现有的真菌分类系统。我们应该顺势而上,利用我国丰富的真菌资源,为真菌分类学的发展做出应有贡献。与此同时,真菌分类学也面临着十分严峻的挑战。挑战主要来自3个方面,一是研究变得越来越综合,不但需要有相应的研究经费支持,而且要求从事该领域的研究人员技术更全面、知识更广博及知识更新速度更快捷;二是新物种描述进度偏慢,远远不能满足人们对物种认识和利用的日益增长的需要;三是研究人员亟需创新研究模式,以新技术、新思路、新机制来构建新的真菌分类学,加速新物种的发现和描述进度,最终为社会进步和科学发展服务。     

Molecular taxonomy: description of a cryptic Petitia species (Polychaeta: Syllidae) from the island of Mahé (Seychelles, Indian Ocean) using RAPD markers and ITS2 sequences

Petitia occulta sp. n. provides an example demonstrating that a morphologically indistinguishable species taxon can be described by molecular markers alone. Phenotypically the polychaete belongs to Petitia amphophthalma Siewing, 1956, one of the numerous meiofaunal species that have previously been regarded as cosmopolitan. Genotypically, however, by means of randomly amplified polymorphic DNA (RAPD)–polymerase chain reaction (PCR) (a DNA-fingerprinting technique) the population on the Indo-Pacific island of Mahé can be identified as a distinct taxonomic entity as: (1) genetic distance values between the Petitia from the Seychelles and from other sites (Mediterranean, Canary Islands) are relatively great; (2) differently generated cluster analyses of genetic distances produce phenograms revealing a distinctly separate clade (bootstrap 100%) for the Seychelles animals; and (3) the Seychelles animals are characterized by eight monomorphic diagnostic (i.e. autapomorphic) DNA-fragments. The RAPD procedure in this case requires the preparation of the whole organisms and, thus, no holotype is available. Instead the RAPD band-pattern with the diagnostic markers of one individual obtained with six primers, isolated DNA of one individual, and syntypes in the form of fixed, complete individuals are deposited. Species differentiation is confirmed by genomic DNA sequencing (ITS2).     

DNA taxonomy, cryptic speciation and diversification of the Neotropical-African liverwort, Marchesinia brachiata (Lejeuneaceae, Porellales)

The Neotropical-African liverwort Marchesinia brachiata has long been regarded as a polymorphic species. This hypothesis is examined using a dataset including sequences of the nuclear internal transcribed spacer region and the plastidic trnL–trnF region of 39 Marchesinia accessions. Maximum parsimony, maximum likelihood and Bayesian analyses indicate that Marchesinia robusta is nested within M. brachiata s.l. The molecular topologies support at least three partly sympatric biological species within M. brachiata s.l., the Neotropical M. bongardiana and M. languida, and the Neotropical-African M. brachiata s.s. These species are incompletely separated by subtle differences in underleaf shape and leaf dentation. Long branches within M. brachiata s.s. suggest ongoing speciation processes that are not yet reflected in distinguishable morphological variation. Divergence time estimates based on nrITS sequence variation and the liverwort fossil record indicate an establishment of the species M. bongardiana, M. brachiata, M. languida, M. madagassa, and M. robusta in the Late Oligocene and Miocene. The intraspecific diversity shows distinctive patterns with evidence for constant accumulation of genetic diversity in M. robusta and M. brachiata whereas M. bongardiana and M. languida likely went through a recent extinction or expansion process as indicated by the bottleneck pattern of genetic diversity. The tropical American-African disjunction of M. brachiata is the result of dispersal rather than Western Gondwanan vicariance.