Species Hypotheses Research Articles

From Parasitized to Healthy-Looking Ants (Hymenoptera: Formicidae): Morphological Reconstruction Using Algorithmic Processing.

Background: Parasites cause predictable alternative phenotypes of host individuals. Investigating these parasitogenic phenotypes may be essential in cases where parasitism is common or taxa is described based on a parasitized individual. Ignoring them could lead to erroneous conclusions in biodiversity-focused research, taxonomy, evolution, and ecology. However, to date, integrating alternative phenotypes into a set of wild-type individuals in morphometric analysis poses extraordinary challenges to experts. This paper presents an approach for reconstructing the putative healthy morphology of parasitized ants using algorithmic processing. Our concept enables the integration of alternative parasitogenic phenotypes in morphometric analyses. Methods: We tested the applicability of our strategy in a large pool of Cestoda-infected and healthy individuals of three Temnothorax ant species (T. nylanderi, T. sordidulus, and T. unifasciatus). We assessed the stability and convergence of morphological changes caused by parasitism across species. We used an artificial neural network-based multiclass classifier model to predict species based on morphological trait values and the presence of parasite infection. Results: Infection causes predictable morphological changes in each species, although these changes proved to be species-specific. Therefore, integrating alternative parasitogenic phenotypes in morphometric analyses can be achieved at the species level, and a prior species hypothesis is required. Conclusion: Despite the above limitation, the concept is appropriate. Beyond parasitogenic phenotypes, our approach can also integrate morphometric data of an array of alternative phenotypes (subcastes in social insects, alternative morphs in polyphenic species, and alternative sexes in sexually dimorphic species) whose integrability had not been resolved before.

Clustering community science data to infer songbird migratory connectivity in the Western Hemisphere

AbstractMigratory connectivity describes the spatial linkage among migrating individuals through time. Accounting for it is necessary for full annual cycle conservation planning, to avoid uneven protection leading to overall population declines. However, conventional methods used to study migratory connectivity usually demand substantial fiscal and human resources. We present a methodology that infers patterns of migratory connectivity for songbirds using relative abundance models created from eBird, a global community science program. We compare our inferences with previously described patterns of migratory connectivity for two species assumed to exhibit broadscale parallel migration strategies: wood thrush (Hylocichla mustelina) and Wilson's warbler (Cardellina pusilla). Initial findings suggest that our method has the potential to be a rapid and inexpensive way to infer broad patterns of connectivity for species that do not engage in leapfrog migration nor deviate much from parallel migration. Our flexible framework can be used to guide sampling designs for studies of migratory connectivity and to generate hypotheses for species in need of urgent conservation planning for which migratory connectivity has not yet been established.

Phylogeography and species delimitation of the Neotropical frog complex (Hylidae: Scinax granulatus)

AbstractUnderstanding which factors driving the genetic structure, geographic distribution patterns, and divergence of populations/species are of great interest in ecology and evolutionary biology. Phylogeographic and species hypotheses combined to distribution models may elucidate which phenomena drove evolutionary history of the biota of different biomes and ecoregions. Herein, we used distribution, environmental and genetic data to shed light on the evolutionary diversity of the Scinax granulatus complex, exploring the phylogeographic patterns, genetic structure and species boundaries across the Pampa and Southern Atlantic Forest biomes. We recovered four mitochondrial lineages which correspond to two putative species within the S. granulatus complex. We used genetic data to define species hypothesis with three discovery methods: bGMYC, bPTP and ASAP, and two delimitation approaches: BPP and BPP + gdi. We validated the species boundaries, confirming the differentiation of Scinax sp. lineage D from Atlantic Forest lowlands habitats, based on genetic data, ecological divergence and monophyly. Lineage D exhibited niche differentiation from S. granulatus sensu stricto (s.s.) based on distribution and environmental data. The climatic suitability of S. sp. D is defined by thermal variables, while that of S. granulatus s.s. was associated with rainfall. The diversification of the S. granulatus complex began during the Pliocene, but the colonization and divergence of lineages took place more recently during the Pleistocene. This study strongly suggests species‐level evolutionary divergence among lineages of S. granulatus complex, and highlights the need to carry out a comprehensive evaluation of diagnostic characters to confirm the lineage D as a distinct species.

Ten new species of Ulva (Ulvophyceae, Chlorophyta) discovered in New Caledonia: genetic and morphological diversity, and bloom potential

ABSTRACT Ulva is a green macroalgal genus with rich species diversity and worldwide distribution. While current knowledge on Ulva diversity focuses on temperate regions, genetic and morphological data in tropical and subtropical areas are scarce and the species richness is not clearly defined. The genus is known for its bloom-forming ability that can induce green tides leading to severe environmental and economic damage. In the last two decades, several important blooms of Ulva spp. have occurred in New Caledonia, requiring further investigations to identify the species involved. As knowledge of New Caledonian Ulva diversity is limited, an update to the Ulva spp. inventory in the area is essential. Based on Ulva specimens collected throughout New Caledonia (Grande Terre, Isle of Pines and Loyalty Islands), we (1) reassessed species diversity using species delimitation methods, (2) analysed morpho-anatomical characters to identify species and/or enrich their diagnosis, and (3) reconstructed a multilocus phylogeny (ITS, rbcL, tufA) of the genus. We found 21 secondary species hypotheses (SSHs) among our dataset, from which five were successfully assigned to U. lactuca, U. ohnoi, U. tepida, U. meridionalis and U. taeniata. Ten SSHs were defined as new species for which we provided taxonomic description, and six other SSHs were singletons that will need to be data-enriched for better interpretation. Our concatenated multilocus matrix included 61 Ulva species. Of these, 15 species were found in New Caledonia and were moderately to strongly supported. Among the Ulva species found in New Caledonia, seven are known to be bloom-forming which highlights the need for strict regulation and regular monitoring of water quality, particularly in areas exposed to strong nutrient input where these species can form green tides.

A striking color variation is detected in Poneratestacea Emery, 1895 (Hymenoptera, Formicidae) across its Western Palaearctic geographic range.

In this paper, we provide numeric morphology-based evidence that the dark-colored Poneracoarctatavar.lucida Emery, 1898, formerly considered a synonym of P.coarctata (Latreille, 1802), is conspecific with the lighter-colored Poneratestacea Emery, 1895. Species hypotheses are developed via NC-PART clustering, combined with Partitioning Algorithm based on Recursive Thresholding (PART), and via PCA combined with gap statistics. We obtained our results from an extensive dataset from the 10 continuous morphometric traits measured on 165 workers belonging to 73 nest samples. Linear discriminant analysis (LDA) confirmed the grouping of hypotheses generated by exploratory analyses with 100% classification success when all ten morphometric traits were involved. The Anatolian Turkish black and the predominantly European yellow samples, did not separate based on their morphometric characteristics. These two color variations broadly overlap in their geographic range in Anatolian Turkey. The investigated type series of Poneracoarctatavar.lucida Emery, 1898 (collected from Kazakhstan) fell within the P.testacea cluster instead of P.coarctata and is also classified with high certainty as P.testacea by confirmatory LDA. Therefore, we propose the synonymy of Poneracoarctatavar.lucida Emery, 1898 with Poneratestacea Emery, 1895. As no other morphological differences than color patterns were detected between the “black” and “pale” P.testacea samples, we hold that these populations constitute geographically occurring color variations of the same species. Finally, our quantitative morphology-based results show that relying on color patterns is not a robust approach in identifying European Ponera samples, particularly in the east, but using multivariate analyses of morphometric traits is advised instead.

A taxonomic revision of the Malagasy endemic subgenus Mayria of the genus Camponotus (Hymenoptera, Formicidae) based on qualitative morphology and quantitative morphometric analyses.

The subgenus Mayria of the genus Camponotus (Hymenoptera: Formicidae) is revised. The subgenus is endemic to Madagascar where it occupies a broad range of habitats, from deciduous and dry forest to rainforest. A taxonomic review is provided of this subgenus, integrating multiples lines of evidence including qualitative morphology and quantitative morphometry. Species hypotheses are formed by Nest Centroid clustering. In total, 36 species are treated, of which eleven are newly described: Camponotusandrianjakasp. nov., Camponotusantsaraingysp. nov., Camponotuschrislainisp. nov., Camponotusclaverisp. nov., Camponotusivadiasp. nov., Camponotusjjacquiasp. nov., Camponotusmaintilanysp. nov., Camponotusnorvigisp. nov., Camponotusihazofotsysp. nov., Camponotustsimelahysp. nov., Camponotuszorosp. nov. Five species are redescribed. Camponotusthemistocles Forel stat. nov., is raised to species. In addition, the subgenus is redefined to include 39 species. Twenty-two previously described species are transferred to this subgenus and thirteen species previously placed in the subgenus are transferred out of the subgenus. Nine morphologically consistent species groups are delineated to facilitate species identification within the subgenus. This revision includes a classification, a key to species groups, and an updated key to species based on the minor worker caste.

Vertebral morphology in extant porpoises: Radiation and functional implications.

Vertebral morphology has profound biomechanical implications and plays an important role in adaptation to different habitats and foraging strategies for cetaceans. Extant porpoise species (Phocoenidae) display analogous evolutionary patterns in both hemispheres associated with convergent evolution to coastal versus oceanic environments. We employed 3D geometric morphometrics to study vertebral morphology in five porpoise species with contrasting habitats: the coastal Indo-Pacific finless porpoise (Neophocaena phocaenoides); the mostly coastal harbor porpoise (Phocoena phocoena) and Burmeister's porpoise (Phocoena spinipinnis); and the oceanic spectacled porpoise (Phocoena dioptrica) and Dall's porpoise (Phocoenoides dalli). We evaluated the radiation of vertebral morphology, both in size and shape, using multivariate statistics. We supplemented data with samples of an early-radiating delphinoid species, the narwhal (Monodon monoceros); and an early-radiating delphinid species, the white-beaked dolphin (Lagenorhynchus albirostris). Principal component analyses were used to map shape variation onto phylogenies, and phylogenetic constraints were investigated through permutation tests. We established links between vertebral morphology and movement patterns through biomechanical inferences from morphological presentations. We evidenced divergence in size between species with contrasting habitats, with coastal species tending to decrease in size from their estimated ancestral state, and oceanic species tending to increase in size. Regarding vertebral shape, coastal species had longer centra and shorter neural processes, but longer transverse processes, while oceanic species tended to have disk-shaped vertebrae with longer neural processes. Within Phocoenidae, the absence of phylogenetic constraints in vertebral morphology suggests a high level of evolutionary lability. Overall, our results are in accordance with the hypothesis of speciation within the family from a coastal ancestor, through adaptation to particular habitats. Variation in vertebral morphology in this group of small odontocetes highlights the importance of environmental complexity and particular selective pressures for the speciation process through the development of adaptations that minimize energetic costs during locomotion and prey capture.

Phylogenetic relatedness and competition: a pot experiment with semiarid tree species

Background: Factors determining the coexistence of species have been recognized since Darwin, but empirical studies have brought the relationship between niche similarity and competition into question. Knowing the mechanisms of coexistence makes it possible to predict biological invasions and determine better species combinations for the restoration and recovery of degraded areas. The aim of this study was to test the competition-relatedness hypothesis for semiarid tree species. Thus, an experiment was carried out with a phylogenetic gradient of tree species, planted in pairs. The phylogenetically closest pair consisted of congeneric species of the same clade, the intermediate pair comprised congeneric species of distinct clades, and the more distant pair were species of the same family. Results: Our results show that the phylogenetically closest and the more distant pairs corroborated the competition-relatedness hypothesis, but the presence of one species with high competitive ability in the intermediate pair caused an unexpected pattern. Conclusion: Niche differences are important for coexistence, but it is necessary to know the competitive ability of each species and the specific associations that are more productive to improve the efficiency of restoration programs and to reveal the degree of aggressiveness in the case of invasive species.

Integrative taxonomy of the stick insect genus

Austrocarausius Brock, 2000 is a stick insect (Phasmatodea: Lonchodidae) genus containing two species restricted to the tropical rainforests of northern Queensland. Recent specimen collections between the two species’ type localities, Lizard Island and Rockhampton, have suggested that Austrocarausius might represent more than the two nominal species. Here, we apply morphological and molecular analyses to revise the taxonomy of this genus. Using both field-collected and historic museum samples, we developed morphological species hypotheses and descriptions. Genetic sequencing of mitochondrial COI and 16S were undertaken for species delimitation and phylogenetic analysis, including an estimate of the evolutionary timescale of the genus. Based on these results, we propose nine new Austrocarausius species, increasing the number of species in the genus to eleven: A. nigropunctatus (Kirby, 1896), A. mercurius (Stål, 1877), A. coronatus sp. nov., A. decorus sp. nov., A. eirmosus sp. nov., A. gasterbulla sp. nov., A. tuberosus sp. nov., A. macropunctatus sp. nov., A. truncatus sp. nov. A. waiben sp. nov. and A. walkeri sp. nov. Our results suggest Austrocarausius species diversified over the last c. 25–70 Ma, resulting in the now endemic distributions in the tropical rainforests of the central and northern Queensland coasts. This is the first integrative systematic study of an Australian phasmid genus, combining morphological, molecular and biogeographical methods. Additional species of Austrocarausius likely remain undescribed as can be inferred from methodical sampling of rainforest patches along the Queensland coast.

Improving Taxonomic Practices and Enhancing Its Extensibility—An Example from Araneology

Planetary extinction of biodiversity underscores the need for taxonomy. Here, we scrutinize spider taxonomy over the last decade (2008–2018), compiling 2083 published accounts of newly described species. We evaluated what type of data were used to delineate species, whether data were made freely available, whether an explicit species hypothesis was stated, what types of media were used, the sample sizes, and the degree to which species constructs were integrative. The findings we report reveal that taxonomy remains largely descriptive, not integrative, and provides no explicit conceptual framework. Less than 4% of accounts explicitly stated a species concept and over one-third of all new species described were based on 1–2 specimens or only one sex. Only ~5% of studies made data freely available, and only ~14% of all newly described species employed more than one line of evidence, with molecular data used in ~6% of the studies. These same trends have been discovered in other animal groups, and therefore we find it logical that taxonomists face an uphill challenge when justifying the scientific rigor of their field and securing the needed resources. To move taxonomy forward, we make recommendations that, if implemented, will enhance its rigor, repeatability, and scientific standards.

Incongruent molecular and morphological variation in the crab spider Synemaglobosum (Araneae, Thomisidae) in Europe.

Establishing species boundaries is one of the challenges taxonomists around the world have been tackling for centuries. The relation between intraspecific and interspecific variability is still under discussion and in many taxa it remains understudied. Here the hypothesis of single versus multiple species of the crab spider Synemaglobosum (Fabricius) is tested. The wide distribution range as well as its high morphological variability makes this species an interesting candidate for re-evaluation using an integrative approach. This study combines information from barcoding, phylogenetic reconstruction based on mitochondrial CO1 and ITS2 of more than 60 specimens collected over a wide range of European localities, and morphology. The findings show deep clades with up to 6% mean pairwise distance in the CO1 barcode without any biogeographical pattern. The nuclear ITS2 gene did not support the CO1 clades. Morphological assessment of somatic and genital characters in males and females and a morphometric analysis of the male palp uncovered high intraspecific variation that does not match the CO1 or ITS2 phylogenies or biogeography either. Screening for endosymbiotic Wolbachia bacteria was conducted and only a single infected specimen was found. Several scenarios might explain these inconsistent patterns. While the deep divergences in the barcoding marker might suggest cryptic or ongoing speciation or geographical isolation in the past, the lack of congruent variation in the nuclear ITS2 gene or the studied morphological character systems, especially the male palp, indicates that S.globosum might simply be highly polymorphic both in terms of its mtDNA and morphology. Therefore, more data on ecology and behaviour and full genome sequences are necessary to ultimately resolve this taxonomically intriguing case.

Podocarpus in the palaeogeographically complex island of Hispaniola: A stepping‐stone colonization and conservation recommendations

AbstractAimHispaniola is the second largest island in the Caribbean and a hot spot of biodiversity. The island was formed by the fusion of a northern and southern palaeo‐islands during the mid‐Miocene (15 Ma). The historical split of Hispaniola together with repeated marine incursions during the Pleistocene is known to have influenced lineage divergence and genetic structure in a few birds and mammals, but the effect on vascular plants is less understood. The conifer genus Podocarpus has two species, P.hispaniolensis and P.buchii, that are endemic to the mountains of Hispaniola and are IUCN endangered. The former occurs in the mountains of the north, and the latter in the south, with a region of sympatry in the Cordillera Central. Here, we evaluate the historical split of the two palaeo‐islands and repeated marine incursions as dispersal barriers to the geographical distribution of genetic diversity, genetic structure, divergence patterns and the historical demography of the two species.LocationHispaniola island, Caribbean.MethodsUsing genotyping‐by‐sequencing in 47 Podocarpus samples, we identified two sets of single nucleotide polymorphisms for our analyses (74,260 and 22,657 SNPs). We conducted a phylogenetic and an approximate Bayesian computation analysis to test evolutionary hypotheses of sympatric and allopatric speciation and stepping‐stone colonization.ResultsPodocarpus showed a population genetic structure that corresponds to the geographic distribution of the species. Podocarpus on Hispaniola fit a stepping‐stone colonization model with bottlenecks at each mountain colonization event and speciation in Cordillera Central.Main conclusionsThe historical events in question did not seem to have influenced the genetic structure, diversity or demography of Podocarpus; instead, the current geographic barriers imposed by lowland xeric valleys did. The clear divergence between species together with the elevated within‐population genetic diversity and significant genetic structure calls for a multi‐population in situ conservation of each species.

Molecular species delimitation refines the taxonomy of native and nonnative physinine snails in North America

Being able to associate an organism with a scientific name is fundamental to our understanding of its conservation status, ecology, and evolutionary history. Gastropods in the subfamily Physinae have been especially troublesome to identify because morphological variation can be unrelated to interspecific differences and there have been widespread introductions of an unknown number of species, which has led to a speculative taxonomy. To resolve uncertainty about species diversity in North America, we targeted an array of single-locus species delimitation methods at publically available specimens and new specimens collected from the Snake River basin, USA to generate species hypotheses, corroborated using nuclear analyses of the newly collected specimens. A total-evidence approach delineated 18 candidate species, revealing cryptic diversity within recognized taxa and a lack of support for other named taxa. Hypotheses regarding certain local endemics were confirmed, as were widespread introductions, including of an undescribed taxon likely belonging to a separate genus in southeastern Idaho for which the closest relatives are in southeast Asia. Overall, single-locus species delimitation was an effective first step toward understanding the diversity and distribution of species in Physinae and to guiding future investigation sampling and analyses of species hypotheses.

Molecular species delimitation of shrub frogs of the genus Pseudophilautus (Anura, Rhacophoridae).

Sri Lanka is an amphibian hotspot of global significance. Its anuran fauna is dominated by the shrub frogs of the genus Pseudophilautus. Except for one small clade of four species in Peninsular India, these cool-wet adapted frogs, numbering some 59 extant species, are distributed mainly across the montane and lowland rain forests of the island. With species described primarily by morphological means, the diversification has never yet been subjected to a molecular species delimitation analysis, a procedure now routinely applied in taxonomy. Here we test the species boundaries of Pseudophilautus in the context of the phylogenetic species concept (PSC). We use all the putative species for which credible molecular data are available (nDNA–Rag-1; mt-DNA– 12S rRNA, 16S rRNA) to build a well resolved phylogeny, which is subjected to species delimitation analyses. The ABGD, bPTP, mPTP and bGMYC species delimitation methods applied to the 16S rRNA frog barcoding gene (for all species), 12S rRNA and Rag-1 nDNA grouped P. procax and P. abundus; P. hallidayi and P. fergusonianus; P. reticulatus and P. pappilosus; P. pleurotaenia and P. hoipolloi; P. hoffmani and P. asankai; P. silvaticus and P. limbus; P. dilmah and P. hankeni; P. fulvus and P. silus.. Surprisingly, all analyses recovered 14 unidentified potential new species as well. The geophylogeny affirms a distribution across the island’s aseasonal ‘wet zone’ and its three principal hill ranges, suggestive of allopatric speciation playing a dominant role, especially between mountain masses. Among the species that are merged by the delimitation analyses, a pattern leading towards a model of parapatric speciation emerges–ongoing speciation in the presence of gene flow. This delimitation analysis reinforces the species hypotheses, paving the way to a reasonable understanding of Sri Lankan Pseudophilautus, enabling both deeper analyses and conservation efforts of this remarkable diversification. http://zoobank.org/urn:lsid:zoobank.org:pub:DA869B6B-870A-4ED3-BF5D-5AA3F69DDD27.

Integrative taxonomy clarifies species limits in the hitherto monotypic passion‐vine butterfly genera Agraulis and Dryas (Lepidoptera, Nymphalidae, Heliconiinae)

AbstractThe Heliconiini genera Agraulis and Dryas are widely distributed throughout the Neotropics and into adjacent temperate regions, and although they are currently treated as monotypic, both show significant geographic phenotypic variation. In this work, we employ six genetic markers (4199 bp), two mitochondrial and four nuclear, to perform coalescent species delimitation analyses in Bayesian Phylogenetics and Phylogeography (BPP) and in integrated BPP (iBPP), the latter also includes linear measurements and wings landmarks. We also analyze cytochrome c oxidase I (COI) barcode sequences for each genus using genetic distances, haplotype networks and a character‐based approach. Based on the model testing results, complemented with data from previous studies, we performed morphometric analyses to compare fore and hindwing size, aspect ratio and shape among the new species. In addition, we compared the forewing spot pattern of hypothesizes species using the r package patternize and, for Dryas, compared the colour patterns of mature larvae. Model testing of the molecular species delimitation outputs favoured a seven species hypothesis for Agraulis and a four species hypothesis for Dryas. Average distances among COI barcode sequences of these groups were from 1.09 to 5.81% in Agraulis and from 1.09 to 3.44% in Dryas. Within‐group distances ranged from 0 to 1.11% and between 0 and 2.43%, respectively. NeighborNet haplotype networks showed that all but one of the species are monophyletic, and the character‐based approach found exclusive diagnostic positions for most species, while the rest can be recognized by unique combinations of the 44 informative nucleotide positions analysed. Morphometric analysis supported all species of Agraulis and Dryas based on wing shape, and also in several cases on wing sizes and aspect ratio (hindwing length–forewing length), including A. v. galapagensis, which was absent from the molecular study. The analysis of the forewing spot pattern also revealed differences among most species hypothesis. The colour pattern of the last instar larva is also diagnostic for each Dryas species hypothesis. Locality data for species in both genera show that most of them are allopatric albeit a few have contact zones being parapatric at some locations. Based on the observed genetic differences, which covary with morphology and geographical distribution, we recommend the recognition of eight species of Agraulis: A. incarnata, A. vanillae, A. forbesi new status, A. insularis reinstated status, A. maculosa new status, A. lucina reinstated status, A. galapagensis new status and one undescribed species, and four species of Dryas: D. iulia, D. dominicana revised status, D. lucia revised status and D. alcionea reinstated status. Further work is needed to investigate, which selective forces have led to the current configurations of venation and wing shape, the probable gene flow among species with a focus on Agraulis and gather more data on species ecology.LSIDurn: lsid: zoobank.org: pub: 9E8C9F6E‐91C3‐4FB2‐804D‐1A9C4BD2EABB.

Integrative taxonomic revision of the New Caledonian endemic genus Taophila Heller (Coleoptera: Chrysomelidae, Eumolpinae)

Abstract There are 96 endemic species of Eumolpinae (Coleoptera: Chrysomelidae) described from New Caledonia, but some estimates propose that the actual number could be at least twice this figure. Not surprisingly, when a particular species assemblage has been revised, the number of species in that group increases significantly. Here, we revise the New Caledonian endemic genus Taophila Heller, 1916, the best studied in this fauna and currently known to include eleven species, one in the subgenus Jolivetiana Gómez-Zurita & Cardoso, 2014, and ten in the nominal subgenus. The analysis of morphological differences in a large sample of Taophila and the validation of the resulting species hypotheses in an integrative fashion based on a phylogenetic analysis of partial mtDNA sequences (cox1 and rrnS) resulted in the addition of eleven more taxa. Taxonomic splits mainly reinterpreted the previous observation of mtDNA paraphyly affecting T. subsericea Heller, 1916, shown to represent a complex of species mostly distinguishable by diagnostic differences among females. The new species described are: T. bituberculata n. sp., T. carinata n. sp., T. dapportoi n. sp., T. davincii n. sp., T. draco n. sp., T. goa n. sp., T. hackae n. sp., T. samuelsoni n. sp., T. sideralis n. sp., T. taaluny n. sp. and T. wanati n. sp. These additions and the synonymy T. subsericea Heller = Stethotes mandjeliae Jolivet, Verma & Mille, 2010 n. syn., bring to 21 the total number of species in Taophila. Moreover, we also found the first evidence of mtDNA introgression between species of New Caledonian Eumolpinae, resulting from putative recent hybridization of T. subsericea and T. dapportoi where these species coexist. We describe a model incorporating the mtDNA genealogy of T. subsericea about the conditions that may have favored the secondary geographic encounter required for the hybridization of these species.

Pragmatic Assignment of Species Groups Based on Primary Species Hypotheses: The Case of a Dominant Component of the Southern Ocean Benthic Fauna

Ecological studies that enhance our understanding of the structure and function of the natural world rely heavily on accurate species identification. With rapid sample accumulation and declining taxonomic expertise, cladistics, phylogenetics and coalescent-based analyses have become key tools for identification or discrimination of species. These tools differ in effectiveness and interpretation depending on researcher perspective and the unique evolutionary histories of the taxa. Given the cost and time required for taxonomic assessment of ambiguous species groups, we advocate a pragmatic approach to clarify species assignment. We carried out a case-study on species from the diverse ophiuroid genusOphiacanthacommon in shelf habitats around the Southern Ocean. Although several of the species are formally described with clear and distinctive morphological characters and reproductive strategies (O. vivipara,O. pentactis,O. densispina,O. antarctica, andO. wolfarntzi), recent molecular data has highlighted issues with these morphospecies, the characters that formally define them and their evolutionary histories. Here we provide evidence that key morphological features of species can be deceptive and show that six-armedO. vivipara, for example, is not a widely distributed Southern Ocean species as currently accepted, rather, three disparate clades.Ophiacantha pentactis, described as having five arms, frequently has six arms and the six-armed form is mistakenly classified asO. vivipara. All six-armed specimens collected from the Antarctic continental shelf fall into theO. pentactisspecies clade. Molecular tools designed for species delimitation appear to fail to reflect the “true” species composition. Rather than rely on a single tool for species recognition, we advocate an integrated approach using traditional detailed taxonomic morphology, summary statistics of molecular sequence data from populations, robust phylogenies, sufficient geographical sampling and local biological knowledge to ensure that species hypotheses can be built on mutually supporting lines of evidence.

Rare, deep-water and similar: revision of Sibogasyrinx (Conoidea: Cochlespiridae)

The genus Sibogasyrinx has to date included only four species of rare deep-water Conoidea, each known from few specimens. In shell characters it strongly resembles three distantly-related genera, two of which, Comitas and Leucosyrinx, belong to a different family, the Pseudomelatomidae. A molecular phylogenetic analysis of a large amount of material of Conoidea has revealed the existence of much additional undescribed diversity within Sibogasyrinx from the central Indo-Pacific and temperate Northern Pacific. Based on partial sequences of the mitochondrial cox1 gene and morphological characters of 54 specimens, 10 species hypotheses are proposed, of which six are described as new species: S. subula sp. nov., S. lolae sp. nov., S. maximei sp. nov., S. clausura sp. nov., S. pagodiformis sp. nov. and S. elbakyanae Kantor, Puillandre & Bouchet sp. nov. One of the previously described species was absent in our material. Most of the new species are very similar and are compared to Leucosyrinx spp. Species of Sibogasyrinx are unique among Conoidea on account of the high intrageneric variability in radular morphology. Three distinct radula types are found within Sibogasyrinx, two of which are confined to highly supported subclades.

Species Delimitation of Asteropyrum (Ranunculaceae) Based on Morphological, Molecular, and Ecological Variation.

Objectively evaluating different lines of evidence within a formalized framework is the most efficient and theoretically grounded approach for defining robust species hypotheses. Asteropyrum Drumm. et Hutch. is a small genus of perennial herb containing two species, A. cavaleriei and A. peltatum. The distinction of these two species mainly lies in the shape and size of leaf blades. However, these characters have been considered labile and could not differentiate the two species reliably. In this study, we investigated the variation of the leaf blades of 28 populations across the whole range of Asteropyrum using the landmark-based geometric morphometrics (GMM), sought genetic gaps within this genus using DNA barcoding, phylogenetic reconstruction and population genetic methods, and compared the predicted ecological niches of the two species. The results showed that the leaf form (shape and size) was overlapped between the two species; barcode gap was not detected within the genus Asteropyrum; and little ecological and geographical differentiation was found between the two taxa. Two genetic clusters detected by population genetic analysis did not match the two morphospecies. The results suggest that there are no distinct boundaries between the two species of Asteropyrum in terms of morphology, genetics and ecology and this present classification should be abandoned. We anticipate that range-wide population genomic studies would properly delineate the species boundaries and help to understand the evolution and speciation within Asteropyrum.

Two new species of the problematic harpacticoid genus Itunella (Copepoda, Canthocamptidae)

Abstract The genus Itunella Brady, 1896 has a troubled taxonomic past, partly because of paucity of its members, but mostly because of inadequate research. A lack of detail in species descriptions and redescriptions, absence of alternative methods for testing species hypotheses, combined with a notion that most marine and estuarine animals have wide distributions and enormous intraspecific variability, all resulted in blurring of some interspecific boundaries, synonymizing without examination of the type material, and founding species diagnoses on dubious characters. Itunella yeondeokensis sp. nov. is described here in great detail from a small sandy beach on the east coast of Korea. It differs from all reported and illustrated congeners by an extremely long inner apical seta on the third exopodal segment of second to fourth swimming legs. This is the second member of this genus from Korea, the first one being described from three estuaries also on the east coast. All other congeners are European species. An overview of all published species and records of this genus is provided, as well as a dichotomous key to valid species to aid in their identification. Itunella kieferi sp. nov. is a new name for a single female from Germany, previously reported as a member of a widely distributed and polymorphic species.