Hybridization with invasive Rosa rugosa threatens the genetic integrity of native Rosa mollis

Hybridization between invasive and native species often has severe consequences on fitness and survival of the native relative. We investigated the extent of hybridization between the neophyte Rosa rugosa and native R. mollis, an endangered species in Germany. Rosa mollis is found in only one large population in Germany close to the Baltic coast, which has been heavily invaded by R. rugosa for at least 60 years. We analysed all individuals of R. mollis from this mixed population using microsatellite markers and morphological characters and compared these data with those from allopatric populations of R. mollis and R. rugosa. In the mixed population we identified nine plants (45% of the population) as hybrids between R. mollis (seed parent) and R. rugosa (pollen parent) by the presence of microsatellite alleles private for R. rugosa. These individuals were also morphologically intermediate between the parental species. Gene flow from R. mollis into R. rugosa was negligible. We detected a very low genetic diversity and a low number of seeds per hip in the mixed population of R. mollis, pointing to genetic depletion and low fitness. In the light of these results and the difficulties in removing invasive R. rugosa from European coastlines, we discuss possible conservation strategies for this endangered population. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 472–484.     

Genetically Distinct Populations in an Asian Soldier-Producing Aphid, Pseudoregma bambucicola (Homoptera: Aphididae), Identified by DNA Fingerprinting and Molecular Phylogenetic Analysis

To estimate genetic structure of a soldier-producing aphid, Pseudoregma bambucicola, samples from natural populations throughout southeastern Asia were analyzed by a DNA fingerprinting technique. We unexpectedly found that P. bambucicola comprises two geographic groups, the northern group and the southern group, which are genetically distinct from each other but morphologically almost indistinguishable. Molecular phylogenetic and statistical analyses based on mitochondrial ribosomal DNA sequences demonstrated that the northern and southern groups of P. bambucicola are not closely related but constitute distinct lineages in the genus Pseudoregma. Detailed morphological reexamination revealed that the two groups could be distinguished by the number of setae on the 8th abdominal tergite of 1st instar nymphs and soldiers. From these results, it was suggested that P. bambucicola should be divided into two species. The northern group from Japan, Taiwan, Hong Kong, and northern Vietnam retains the name P. bambucicola, whereas we suggest that the name P. carolinensis (R. Takahashi, 1941, Tenthredo 3, 208–220) should be used for the southern group from Thailand, Malay Peninsula, Java, Irian Jaya, and Micronesia. The morphological resemblance between P. bambucicola and P. carolinensis might be due to shared ancestral characters of the genus Pseudoregma.     

Species limits and morphometric and environmental variation within the South Andean and Patagonian Mulinum spinosum species-group (Apiaceae-Azorelloideae)

Delimiting species is an important, but frequently difficult aspect of systematics that should be addressed using data from multiple sources. Here we combine morphometric analyses and environmental characteristics to delimit species in the South Andean and Patagonian taxonomically difficult species-group composed by Mulinum spinosum, M. echinus and M. leptacanthum (Apiaceae-Azorelloideae). Molecular phylogenies have shown that these three species form part of a polytomy together with other Mulinum species, and therefore these data are not useful for their delimitation. We include measurements of 25 morphometric variables from 163 herbarium specimens and perform univariate and multivariate principal component analysis (PCA) and discriminant analysis (DA) to establish the limits amongst the three mostly sympatric, morphologically similar, and phylogenetically unresolved species. We also use 19 bioclimatic and three geographic variables from localities of the specimens to infer environmental characteristics of the taxa and test their relation with morphological variation. Morphological evidence supports the inclusion of M. echinus within the morphologically and climatically variable M. spinosum, and rejects its recognition as a distinct taxon at any rank. On the contrary, M. leptacanthum is considered a morphologically distinct species, generally restricted to high altitude areas of the southern Andes with a cooler and wetter climate. Within the widespread M. spinosum, environmental gradients of precipitation and temperature relate to morphological gradients (e.g., in leaf and inflorescence sizes, in leaf acicularity, and in fruit-wing width). These last results showed that the large morphological variation in vegetative and reproductive characteristics of this species that grows in arid and semiarid habitats are related to regional climatic gradients that have probably been important in the evolution of this species' plasticity, diversification, and differentiation.     

Systematics of the amphiatlantic Microphthalmus-listensis-species-group (Polychaeta: Hesionidae): Facts and concepts for reconstruction of phylogeny and speciation

Previous studies established the existence of morphologically highly similar amphiatlantic populations of the predominantly interstitial genus Microphthatmus (European coastline - from the German Bay to the Bay of Biscaya; American coastline - from Maine to Massachusetts and at the coast of North Carolina). Originally these three populations were seen as belonging to a single species. By using a broad spectrum of different methodologies for character investigations (especially through the use of electron microscopy) three, distinct species can now be distinguished: M. listensis Westheide 1967, M. nahantensis n. sp. and M. carolinensis n. sp. While habitat structure and external morphology - generally important in polychaete systematics - were found to be rather similar between the three species, this study uncovered distinct differences between the species in their internal organization. Such sharp differences could even be followed down to the ultrastructure of single cells (e. g. copulatory stylets, position and number of ovaries, sperm and secretory granules of male accessory glands). Within population character variability is significantly lower in several features of M. carolinensis than in the same characters of the other two species. Similarities as well as differences have been noted in behavioural features and population dynamics between the species.     

Natural hybridization origin of <Emphasis Type="Italic">Rhododendron agastum </Emphasis>(Ericaceae) in Yunnan,China: inferred from morphological and molecular evidence

The natural hybridization that occurs between two sympatric species of Rhododendron subgenus Hymenanthes in Yunnan, China, was investigated. The assumed parents, Rhododendron delavayi Franch. and R. decorum Franch., are morphologically distinct, and the putative hybrid species, R. agastum Balf. f. et W. W. Smith, has an intermediate morphology. We used the main morphological characters, sequences of the nuclear ribosomal DNA ITS region, and the chloroplast DNA trnL-F intronspacer to analyze the three species, and compared these morphological and molecular data with an artificial hybrid between R. decorum (♀) × R. delavayi (♂). From the results, we conclude that R. agastum is a natural hybrid between a female R. delavayi and a male R. decorum.     

Molecular diversity and relationships of North American Elymus trachycaulus and the Eurasian E. caninus species

The morphological similarity of Elymus trachycaulus to the Eurasian E. caninus has often been noted. This has lead to controversial and contradicting taxonomic treatments. Nevertheless, there has been no systematic investigation on molecular genetic similarity between E. trachycaulus and E. caninus. In this study, random amplified polymorphic DNA (RAPD) analysis was used to study the similarity between the two species. RAPD analysis of 38 samples representing E. caninus and E. trachycaulus complex yielded 111 interpretable RAPD bands. The Jaccard’s similarity values for E. caninus ranged from 0.38 between accessions H10345 and H10353 to 0.97 between accessions H8745 and H10096, with an average of 0.67. The Jaccard’s similarity values for E. trachycaulus complex ranged from 0.09 between E. trachycaulus ssp. subsecundus (PI 537321) and E. trachycaulus ssp. violaceus (PI 272612) to 0.78 between accessions PI 315368 and PI 372644, with an average of 0.43. The results from different analyses (NJ and PCA) were similar but not identical. The molecular genetic separation between E. caninus and E. trachycaulus was consistent. The PCA analysis clearly separated all E. caninus accessions from E. trachycaulus and its subspecies. The NJ analysis also showed separation between most accessions of E. caninus and E. trachycaulus. Further analysis excluding E. trachycaulus ssp. subsecundus and ssp. violaceus revealed that E. caninus species and E. trachycaulus species were clearly separated into two distinct groups. The RAPD data thus support the treatment of E. caninus and E. trachycaulus as distinct species. The analyses further indicate that E. violaceus is nested within E. trachycaulus, and more related to E. trachycaulus complex rather than to E. caninus.     

Molecular and morphological patterns across Acanthocyclops vernalis‐robustus species complex (Copepoda,Cyclopoida)

Bláha, M., Hulák, M., Slouková, J. & Tě?itel, J. (2010). Molecular and morphological patterns across Acanthocyclops vernalis‐robustus species complex (Copepoda, Cyclopoida).—Zoologica Scripta, 39, 259–268. Morphological traits within Acanthocyclops (Kiefer, 1927) are highly variable, and morphology is too constrained to give complete information of phylogenetic relationships. This study combined morphological and molecular techniques to investigate the taxonomic and phylogenetic relationships of three species of Acanthocyclops (Acanthocyclops trajani, Acanthocyclops einslei and Acanthocyclops vernalis) inhabiting continental Europe. Morphological indices subjected to principal component analysis (PCA) separated sample populations into three distinct clusters corresponding with the taxonomic status of the species analysed. In addition, the taxonomy status of A. trajani and A. einslei was in agreement with molecular data; however, the intraspecific variation in sequences of 12S rRNA was lower in contrast to specimens morphologically determined as A. vernalis, which were divided into two deeply divergent clades, based on mtDNA sequence divergences. Moreover, high sequence divergence (26%) between these clades indicated the existence of another species that may not be a sister taxon of A. vernalis s.s. Results point to the need for further taxonomic work on Acanthocyclops.     

Phylogeny and form in fishes: Genetic and morphometric characteristics of dragonets (Foetorepus sp.) do not align

Measures of biodiversity are often hindered by a lack of methodological practices that distinguish cryptic or morphologically similar cohabiting species. This is particularly difficult for marine fishes where direct observations of the ecology and demography of populations are difficult. Dragonets (Foetorepus c.f. calauropomus) were collected as bycatch from research trawls deployed in waters off north-eastern Tasmania, Australia. Morphometric and genetic analyses were conducted on the 43 specimens recovered. Sequence analysis of two mitochondrial loci distinguished three genetic clusters, each having levels of dissimilarity consistent with species-level distinctions between other members of the Callionymidae. While clear morphological distinctions were observed between male and female fish, limited morphometric analyses could not differentiate between members of the three genetic groups. This finding highlights questions about the ability of genetically distinct but morphologically similar groups to occupy the same ecological niche, and points to additional and undescribed hidden biodiversity amongst cryptic species of fish.     

Systematics of a widespread Southeast Asian frog,Rana chalconota (Amphibia: Anura: Ranidae)

The abundant Sundaland forest frog, Rana chalconota, has long been considered a single widespread species, although some authors have recommended its division into regional subspecies. The discovery of co‐occurring pairs of morphologically distinct populations in three widely separated parts of the range led to a morphological and molecular analysis of populations from all parts of the known range. The results suggest that R. chalconota consists of at least seven species from Thailand through Borneo and Java. Existing names are applied to three of these species, R. chalconota (Schlegel), R. raniceps (Peters) and R. labialis Boulenger. We describe four others as new species and suggest the existence of one or two additional, unnamed species. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 123–147.     

Systematic placement of the recently discovered beetle family Meruidae (Coleoptera: Dytiscoidea) based on molecular data

The family Meruidae has been established recently for the newly discovered species Meru phyllisae Spangler & Steiner, 2005 from Southern Venezuela. These beetles are morphologically highly distinct and at a body length of 0.8 mm represent the perhaps smallest individuals of Adephaga. Here, we use DNA sequence data to place this enigmatic taxon relative to other aquatic groups in this suborder. Meruidae was most closely associated with Noteridae, supporting a previous analysis of morphological structures which had suggested this sister relationship, albeit with weak support. While different alignment strategies did not affect the topology, the precise placement of Meruidae was affected by the choice of tree reconstruction method. Bayesian inference suggests a sister relationship of Meruidae + Noteridae, while parsimony analyses retrieve Meruidae + Notomicrus (a basal noterid genus), which combined are the sister group of all remaining Noteridae. Considering morphological evidence, the former placement appears more plausible.     

Proboscis profiler: a tool for detecting acanthocephalan morphotypes

Molecular studies conducted over the past 25 years have revealed previously unrecognised diversity in the phylum Acanthocephala. Several nominal species have been shown to represent complexes of morphologically cryptic biological species, a situation potentially confounding the analysis of ecological data. A software tool, ‘Proboscis profiler’, was developed to detect morphological heterogeneity in collections of superficially similar acanthocephalan worms based on the multivariate statistical analysis of proboscis hook dimensions. Proboscis profiler identifies objective, natural groups in a collection of acanthocephalans which may correspond to distinct biological species or populations. Initial trials demonstrate that Proboscis profiler can discriminate biological acanthocephalan species of the Echinorhynchus gadi Zoega in Müller, 1776 complex and differentiate between dorsal and ventral hook rows from the proboscis of E. salmonis Müller, 1784. Proboscis profiler is free software and can be downloaded from .     

Zonal plant communities of the Ribesalbes‐Alcora Basin (La Rinconada mine,eastern Spain) during the early Miocene

Changes in lobule morphology in Radula subgenus Cladoradula show liverworts have the capacity for dramatic, relatively rapid morphological change by heterochrony. In individuals of R. bipinnata, R. boryana and R. tenax, lobules on secondary and tertiary shoots are progenetic with respect to lobules on primary shoots, in that the slope of the relationship between growth duration and shape does not change. However, in R. campanigera, lobules on secondary and tertiary branches exhibit different slopes from primary branches, but have the same growth duration, a pattern consistent with neoteny. The trajectory of allometric growth is extended or truncated in different species compared with outgroup and ancestral nodes. Changes in duration of lobule growth explain 85% of variation in lobule shape between species. Species are related by relatively shallow nodes in the crown of the Radula subgenus Cladoradula clade, suggesting that divergence and associated heterochronic changes have occurred relatively recently. The rapid morphological diversification in the crown contrasts with the relative stasis between the ancestral node and R. brunnea, the outgroup used in this analysis. A robust primary axis may be required to hold shoots away from vertical surfaces to maximize light interception, and hypermorphosis in lobule ontogeny could be a by‐product of the longer growth durations required to build axes sufficiently large to perform this structural role. Alternatively, the large auriculate lobules could function in external water transport systems by providing continuity of surfaces for solute transport via capillary action. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 153–175.     

Untangling the taxonomic ambiguities of the spotted seerfish Scomberomorus guttatus with the description of a new species from India

Scomberomorus guttatus has been subjected to a series of synonym assignations over the years. Its taxonomy has been mired with ambiguities due to the greater-than-average morphological variations observed in samples from different regions. An integrated taxonomic revision with molecular support indicated that the species that was thought to be a single entity, in reality, is a complex of three distinct species. They are morphologically distinct with respect to the body depth and elongation, cephalic morphometry, and meristic characteristics. Otolith morphometry and phylogenetic evidence further established the taxonomic divergence within the spotted seerfish complex. The phylogenetic characteristic as indicated by the mitochondrial Cytochrome c Oxidase subunit I (COI) sequence unveiled that S. guttatus had a high intraspecific divergence of 11.1% from its two identical congeners and a divergence of 2.34% between the congeners, indicating scope for categorizing them as separate species. Based on the morphological and molecular evidence, S. guttatus is redescribed; the senior synonym Scomberomorus leopardus is resurrected as a valid species; and a new species Scomberomorus avirostrus n. sp. is described with keys for species distinction.     

Sympatric occurrence of three leaf beetle species of Macroplea Samouelle, 1819 (Coleoptera,Chrysomelidae, Donaciinae) in Finland with a key to species in Northern Europe

Macroplea Samouelle, 1819 is the only known fully aquatic leaf beetle genus with three European species that have earlier been classified by their assumed water salinity preferences. We studied the inter- and intraspecific variation of the specimens living in Northern Europe using both molecular (cytochrome c oxidase subunit I, COI) and morphological evidence. The variation in the COI sequences between M. mutica (Fabricius, 1792) and M. pubipennis (Reuter, 1875) was 8.4%–9%, M. mutica and M. appendiculata (Panzer, 1794) – 3.9%–4.9%, and M. appendiculata and M. pubipennis – 8.8%–9.2%. All three species were sampled together in the Bothnian Sea on the same water plants, showing that neither salinity nor plant species bear a decisive importance in their occurrence in the region. Phylogenetic results suggest the existence of two currently unknown Macroplea species that are evolutionarily close to M. appendiculata. A key to the Nordic species is provided.