Morphological Evidence Research Articles

Morphological evidence of a potential arrhythmogenic substrate in the caudal and cranial vena cava in horses.

Three-dimensional electro-anatomical mapping, previously performed in horses with atrial arrhythmias, has demonstrated the medial region of the caudal vena cava (CaVC), 1-8 cm caudal to the fossa ovalis, as an anatomical predilection site for atrial tachycardia associated with areas of slow conduction and conduction block. Slow conduction has also been recorded in the cranial vena cava (CrVC). To investigate the morphological characteristics of the myocardial sleeves (MS) in the CaVC and CrVC, in order to identify a potential substrate of right sided atrial arrhythmias. Cross sectional. Post-mortem dissection of 37 hearts from adult warmblood horses without known cardiovascular disease. Macroscopic examination of the myocardial distribution, evaluated the MS area, length, width, and shape in the CaVC and the CrVC. At least 2 samples from each vena cava MS were histologically examined using Masson's trichrome staining. Myocardial sleeves into the medial CaVC and into the CrVC were observed in all horses and showed variations in distribution, shape, and size between horses. Their mean ± standard deviation length from the limbus into the CaVC reached 5.7 ± 1.0 cm (maximum 8.3 cm), and from the azygos vein into the CrVC 5.3 ± 1.6 cm (maximum 8.6 cm). Myocardium-free islands were observed in the CaVC and CrVC in 30% and 6% of horses, respectively. Histologically, MS showed a non-uniform myocardial fibre arrangement, with presence of fibroadipose tissue, features known to result in slow conduction and pro-arrhythmia. Study only included horses without history of atrial arrhythmia. Myocardial sleeves are present in both CaVC and CrVC, showing anatomical variations between horses. Tissue characteristics known to favour re-entry were identified indicating that these venae cavae MS are a potential substrate for atrial tachyarrhythmias and a target for treatment by ablation.

On the status of Helicops wettsteini Amaral, 1929, a senior synonym of Hypsiscopus murphyi (SERPENTES: Homalopsidae).

We redescribe the name-bearing types of Helicops wettsteini Amaral, 1929, a species described from central Costa Rica. However, while Helicops wettsteini has been considered in the literature a synonym of Hypsiscopus plumbeus (previously Enhydris plumbea), we present here morphological evidence for considering Helicops wettsteini a synonym of the recently described species Hypsiscopus murphyi Bernstein, Voris, Stuart, Phimmachak, Seateun, Sivongxay, Neang, Karns, Andrews, Osterhage, Phipps & Ruane, 2022, which hence becomes a junior subjective synonym of Hypsiscopus wettsteini (Amaral, 1929).

Armillaria korhonenii, the sixteenth biological species of Armillaria from China

Armillaria korhonenii, designated as Chinese biological species Q (CBSQ) here, is described as a new species based on phylogenetic and morphological evidence as well as the results of mating tests. This species is the sixteenth biological species of Armillaria reported from China following the discovery of 15 previously known biological species. Phylogenetically, A. korhonenii is the earliest divergent lineage of the genus Armillaria as inferred from the nucleotide sequences of the Elongation Factor 1-Alpha (EF1a). Morphologically, it is characterized by its ellipsoid to elongate basidiospores, yellowish orange to honey yellow pileus with fibrillose squamules. Mating tests indicated that A. korhonenii is a tetrapolar heterogeneous species and is inter-sterile with all the tested species except partial compatibility with CBSH.

Campanula bergomensis (Campanulaceae), a new species from Bergamo Prealps (Northern Italy)

A new species of Campanula (Campanulaceae), C. bergomensis sp. nov., is described from the Bergamo Prealps (Orobic Prealps, Lombardy, Northern Italy), based on both morphological and molecular evidence. The new species was considered in the past as an isolated population of C. cespitosa, which presents an eastern Alpine distribution. C. bergomensis is morphologically well distinguishable from C. cespitosa on the number of flowers in the racemose inflorescence, the corolla shape, and the whitish-yellow pollen surface with many spinulae. Genetically, the presence of an insertion of 81-bp in the trnL-F sequences is very characteristic. Further studies are needed to better define the phylogenetic relationship among the three closely related species, C. bergomensis, C. cespitosa and C. cochleariifolia. C. bergomensis inhabits dolomitic debris cones at low elevations. The species is range-restricted and is severely threatened by human activities. Therefore, it is urgent to adopt protection and conservation measures for the new species.

A new species of Zhangixalus (Anura, Rhacophoridae) from Yunnan, China

We described herein Zhangixalus yunnanensissp. nov., a new treefrog species from central and western Yunnan, China, which had previously been confused with Z. nigropunctatus, based on morphological and molecular evidence. Our phylogenetic analyses revealed that the new species is sister to the clade of Z. nigropunctatus and Z. melanoleucus with strong support (100% and 73% for BI and ML, respectively). Our morphological analysis suggested that Z. yunnanensissp. nov. is distinctly different from all known congeners by the combination of the following morphological characters: black blotches on body flank and hind-limb, medium body size (SVL31.3–36.0 mm in males and 47.6–48.6 mm in females), head wider than long, iris yellowish-brown, dorsum uniformly green, vocal sac external, throat black, webbing greyish and fingers webbed one third and toes webbed half. Additionally, we revealed that the specimens ROM 38011 (Sa Pa, Vietnam) and VNMN 4099 (Son La, Vietnam) are neither Z. dorsoviridis nor Z. nigropunctatus, but probably represent one or two cryptic species of Zhangixalus pending further morphological and molecular data. Including the new species described herein, the genus Zhangixalus currently comprises 42 species, 30 of which are distributed in China with 11 species known from Yunnan. Amongst different zoogeographic regions in Yunnan, south-eastern Yunnan has the highest diversity of Zhangixalus, followed by western Yunnan and southern Yunnan. More studies are required to clarify the species diversity of this genus based on multiple lines of evidence (e.g. morphological and molecular data).

The Pylus complex sensu Opitz revisited (Coleoptera: Cleridae: Korynetinae): non-homogeneity of its genera addressed by alternative species-assignment hypothesis.

Apparent superficial non-homogeneity of species assigned to the genera Apopylus Kolib, Fallopylus Opitz and Pylus Newman prompted reassessment of genus characters and species assignment of those genera plus Parapylus Blackburn and Pseudopylus Opitz, all of which were defined by Opitz (2015) primarily on the number of tibial spurs. Morphological investigation resulted in discovery of suites of correlating character state pairs providing more robust evidence for monophyly of the genera under study than tibial spurs alone. On this basis, genus definitions were revised, and species assigned accordingly to the newly defined genera. Taxonomic changes proposed include synonymy of Fallopylus Opitz, 2012 new synonym and Pseudopylus Opitz, 2012 new synonym with Pylus Newman, 1841, plus the following new combinations: Apopylus astrictus (Opitz, 2015) new combination (transferred from Fallopylus); Apopylus creperus (Opitz, 2015) new combination (transferred from Fallopylus); Apopylus leptofustus (Opitz, 2015) new combination (transferred from Fallopylus); Apopylus redactus (Opitz, 2015) new combination (transferred from Fallopylus); Pylus apterus (Opitz, 2015) new combination (transferred from Pseudopylus); Pylus cavus (Opitz, 2015) new combination (transferred from Fallopylus); Pylus cruslumus (Opitz, 2015) new combination (transferred from Apopylus); Pylus kolibaci (Opitz, 2015) new combination (transferred from Apopylus); Pylus nactus (Opitz, 2015) new combination (transferred from Apopylus). Pylus okei Elston, 1929 and Pylus pallipes Macleay, 1872 are returned to their original combinations from Apopylus and Fallopylus respectively. In addition to evidence for the monophyly of genera being based on more robust lines of morphological evidence, the newly defined genera are also more obviously homogenous, with superficially similar looking insects now grouped together.

Convergent and environmentally associated chromatic polymorphism in Bryconops Kner, 1858 (Ostariophysi: Characiformes: Iguanodectidae).

Bryconops Kner, 1858, includes two well defined subgenera based on morphological evidence, with each containing at least one species (B. (Bryconops) caudomaculatus and B. (Creatochanes) melanurus) with a very wide distribution, within which regional populations present color variations. To test if phenotypic variation is related to cladogenetic events, we performed tests for phylogenetic independence and determined the strength of convergence for color characters in relation to water type, as the variation between clear, black and white waters is considered to be one of the major driving forces in the evolution of Amazonian fishes. Color characters for fins above the median line of the body were generally found to be independent from phylogeny and the Wheatsheaf test strongly supports convergence of the dorsal fin color between populations of species in the same type of water, with a similar trend suggested for the color of the dorsal lobe of the caudal fin. This means that simple color characters cannot necessarily be relied upon for taxonomic revisions of the genus as local phenotypic variants may represent environmentally determined plasticity or convergent evolution. Further studies are required to determine the validity of these characters.

Molecular phylogenetics of the Ophiocordyceps sinensis-species complex lineage (Ascomycota, Hypocreales), with the discovery of new species and predictions of species distribution

Ophiocordyceps sinensis is a famous traditional Chinese medicine adapted to the alpine environment of the Qinghai-Tibet Plateau and adjacent regions. Clarification of the species diversity of Ophiocordyceps sinensis and its relatives could expand the traditional medicinal resources and provide insights into the speciation and adaptation. The study is prompted by the discovery of a new species, O. megala, described here from a biodiversity hotspot in the Hengduan Mountains, China. Combined morphological, ecological, and phylogenetic evidence supports its distinctiveness from O. sinensis, O. xuefengensis, and O. macroacicularis. Additionally, based on the phylogenetic construction of Ophiocordyceps, a special clade was focused phylogenetically on the more closely related O. sinensis complex, which was defined as the O. sinensis- species complex lineage. A total of 10 species were currently confirmed in this lineage. We made a comprehensive comparison of the sexual/asexual morphological structures among this species complex, distinguishing their common and distinctive features. Furthermore, using the method of species distribution modelling, we studied the species ocurrences in relation to climatic, edaphic, and altitudinal variables for the eight species in the O. sinensis-species complex, and determined that their potential distribution could extend from the southeastern Qinghai-Tibet Plateau to the Xuefeng Mountains without isolating barrier. Thus, the biodiversity corridor hypothesis was proposed around the O. sinensis-species complex. Our study highlights the phylogeny, species diversity, and suitable distribution of the O. sinensis-species complex lineage, which should have a positive implication for the resource discovery and adaptive evolution of this unique and valuable group.

Phylogeny, biogeography, and character evolution of Anaphalis (Gnaphalieae, Asteraceae).

The HAP clade, mainly including Helichrysum Mill, Anaphalis DC., and Pseudognaphalium Kirp., is a major component of tribe Gnaphalieae (Asteraceae). In this clade, Anaphalis represents the largest genus of Asian Gnaphalieae. The intergeneric relationships among Anaphalis and its related genera and the infrageneric taxonomy of this genus are complex and remain controversial. However, there are few studies that have focused on these issues. Herein, based on the current most comprehensive sampling of the HAP clade, especially Anaphalis, we conducted phylogenetic analyses using chloroplast (cp) genome and nuclear ribosomal DNA (nrDNA) to evaluate the relationships within HAP clade, test the monophyly of Anaphalis, and examine the infrageneric taxonomy of this genus. Meanwhile, the morphological characters were verified to determine the circumscription and infrageneric taxonomy system of Anaphalis. Additionally, the biogeographical history, diversification processes, and evolution of crucial morphological characters were estimated and inferred. Our phylogenetic analyses suggested that Anaphalis is polyphyletic because it nested with Helichrysum and Pseudognaphalium. Two and four main clades of Anaphalis were identified in cp genome and nrDNA trees, respectively. Compared with nrDNA trees, the cp genome trees were more effective for phylogenetic resolution. After comprehensively analyzing morphological and phylogenetic evidence, it was concluded that the achene surface ornamentation and leaf base showed less homoplasy and supported the two Anaphalis lineages that were inferred from cp genome. Our biogeographical analyses based on cp genome indicated that HAP clade underwent rapid diversification from late Miocene to Pliocene. The two Anaphalis lineages appeared to have originated in Africa, then spread to Western and Southern Asia, and subsequently moved into Southwestern China forming a diversity center. The dispersal patterns of the two Anaphalis lineages were different. One dispersed around the world, except in Africa and South America. The other one dispersed to Eastern and Southeastern Asia from the ancestral origin region.

Additions to Crassiparies and Neobrevicollum (Neohendersoniaceae, Pleosporales) associated with woody hosts in Southwest China

During an investigation of ascomycetous fungi from decaying wood in southwest China, seven taxa with sexual morphs were found to be saprobic from terrestrial habitats. These taxa were identified based on morphology, phylogeny, and cultural characteristics. The morphology and phylogenetic evidence placed these new fungal collections in Neohendersoniaceae, distributing in the genera Crassiparies and Neobrevicollum. The phylogenetic analyses of a combined ITS, LSU, SSU, RPB2, and TEF1-α sequence dataset also confirmed their taxonomic placement. A new species, Neobrevicollum biancaeae is introduced to accommodate the two taxa, which have thin-walled ascomata without ostiole, and smaller asci and ascospores compared to the type species, N. oleae. The other five samples were identified as Crassiparies quadrisporus and N. oleae representing three and two taxa, respectively. The identification and establishment of these species are justified based on morpho-molecular analyses. In addition, the new host records of C. quadrisporus and N. oleae were reported. Detailed descriptions and illustrations are provided for collected taxa. This study contributed to the microfungal diversity in Southwest China.

Serpentirhabdias mexicanus n. sp. (Nematoda: Rhabdiasidae), a parasitic lungworm of the nauyaca viper Bothrops asper (Serpentes: Viperidae) in the Mexican Neotropics

Serpentirhabdias mexicanusn. sp. (Nematoda: Rhabdiasidae) is described from the lung of the nauyaca viper Bothrops asper in Puebla State, central Mexico. This new species is the fifth of the genus described having onchia. Among the species included in this group, the new species is morphologically closest to S. viperidicus and S. atroxi. However, it differs from both species mainly by having only one excretory gland (compared to two present in S. viperidicus and S. atroxi). In addition, S. mexicanusn. sp. can be separated of S. viperidicus by tail length, shape of vulval lips, geographic distribution and host species and from S. atroxi by body length, number of papillae in the cephalic region, as well as the host species and geographic distribution. In the present study, we propose the new species based on morphological, host spectrum and genetic evidence. Phylogenetic analysis indicated Serpentirhabdias as a monophyletic group, with two subgroups that are congruent with the presence/absence of onchia in the esophagostome, host association and other relevant morphological characters.

Two new Erythrobasidium species inhabiting the phyllosphere discovered in the Baotianman Nature Reserve in China.

The genus Erythrobasidium is kind of species-scarce and undersampling basidiomycetes. Currently, only six species have been accepted into the genus and the diversity still remains incompletely understood. In this study, five Erythrobasidium strains were isolated in the surface of plant leaves collected from the Baotianman Nature Reserve, Henan Province, central China. Phylogenetic analyses of the small ribosomal subunit (SSU) rRNA gene, the internal transcribed spacer (ITS) region, the D1/D2 domain of the large subunit (LSU) rRNA gene, and the translation elongation factor 1-α (TEF1-α) gene coupled with morphological studies were employed to characterize and identify these isolates. As a result of these, two new species, namely E. turpiniae sp. nov. and E. nanyangense sp. nov., were delimited and proposed based on morphological and molecular evidence. A detailed description and illustration of both new species, as well as their differences with the close relatives in the genus are provided. An identification key for Erythrobasidium species is also provided. This study provides further insights into our understanding of Erythrobasidium species.

Morphological and molecular evidence for a new species of the genus Milnesium Doyère, 1840 (Tardigrada: Apochela) from south America

Tardigrades are aquatic microinvertebrates, that can be found from the poles to the tropical regions. However, knowledge about their diversity and distribution is still limited, especially regarding the Neotropical region. In addition, many species described in the past were considered cosmopolitan but new morphological, morphometric and especially molecular studies have demonstrated the existence of species complexes. The species Milnesium tardigradum Doyère, 1840 is an example that highlights this issue. Many M. tardigradum records made in South America date from the time when this species was considered cosmopolitan and exhibiting large intraspecific variability. However, current revisions of the genus using modern techniques indicate that the M. tardigradum sensu stricto is most likely restricted to the Palaearctic region. In this contribution, we describe a new species, Milnesium iniquum sp. nov. from south-eastern Brazil, with additional records from Argentina and French Guiana, utilising integrative taxonomy framework. The new species is characterised by having smooth cuticle, presence of dorsal pseudoplates, adult claw configuration [3-3]-[3-3] and [2-2]-[2-2] in hatchlings (early positive CC change), with internal and anterior spurs larger than external and posterior spurs and by presence of short cuticular bars on legs IV.

Volvariella lanata (Pluteaceae, Agaricales), a new species from the Middle Volga Region, Russia

One new species of Volvariella (V. lanata) is described based on a combination of morphological and molecular evidence. The species is characterized by rather large basidiomata with grey-brown, fibrillose to pubescent pileus, pubescent stipe and brownish trilobate volva, cheilocystidia with long apical appendages, utriform or fusiform pleurocystidia, and basidiospores 5.9–7.4 × 3.7–5.0 µm. Sequences of nrITS and nrLSU of the studied specimens were generated, and the phylogenetic analyses were performed with Maximum likelihood and Bayesian inference methods for nrITS+nrLSU dataset. The analyses showed that the new species is clustered within the genus Volvariella, forming a distinct phylogenetic lineage with V. krizii as its sister taxon.

Morphological and genetic evidence suggest gene flow among native and naturalized mint species.

Cultivation and naturalization of plants beyond their natural range can bring previously geographically isolated taxa together, increasing the opportunity for hybridization, the outcomes of which are not predictable. Here, we explored the phenotypic and genomic effects of interspecific gene flow following the widespread cultivation of Mentha spicata (spearmint), M. longifolia, and M. suaveolens. We morphologically evaluated 155 herbarium specimens of three Mentha species and sequenced the genomes of a subset of 93 specimens. We analyzed the whole genomes in a population and the phylogenetic framework and associated genomic classifications in conjunction with the morphological assessments. The allopolyploid M. spicata, which likely evolved in cultivation, had altered trichome characters, that is possibly a product of human selection for a more palatable plant or a byproduct of selection for essential oils. There were signs of genetic admixture between mints, including allopolyploids, indicating that the reproductive barriers between Mentha species with differences in ploidy are likely incomplete. Still, despite gene flow between species, we found that genetic variants associated with the cultivated trichome morphology continue to segregate. Although hybridization, allopolyploidization, and human selection during cultivation can increase species richness (e.g., by forming hybrid taxa), we showed that unless reproductive barriers are strong, these processes can also result in mixing of genes between species and the potential loss of natural biodiversity.

A Global Survey of Gravitationally Deformed Volcanoes on Venus

AbstractGravitational instabilities can develop at volcanoes of any size and in any geological setting and can lead to various types of volcano deformation, ranging from small‐scale landslides on the flanks of the edifice to large, deep‐seated sector collapses. As volcanoes grow, they impose an increasing load on the underlying basement, which can result in styles of gravitational deformation where the edifice sags or spreads outward under its own weight. In this study, we utilize our previously developed global catalog of volcanoes on Venus to analyze a subset of edifices that appears to have undergone gravitational deformation. We identify 162 volcanoes that display morphological evidence for gravitational deformation and classify them into four main categories based on associated deformational structures: landsliding, sector collapse, spreading, and sagging. Landsliding of volcano flanks or full sector collapse are the most common and geographically widespread deformational styles on Venus, and account for ∼64% of our data set. Edifices exhibiting structures linked to volcano spreading and sagging are relatively rare; nonetheless, we note for the first time on Venus the presence on a shield volcano of flank terraces, structures linked to sagging. We find that deformed volcanoes are distributed globally, are found at a range of elevations, are spatially proximal to a variety of tectonic structures, and are associated with various crustal thickness values, which together suggest that there are numerous drivers of volcano deformation on Venus.

Prevocalic word-initial glottal stops in Rote: Implications to language revitalisation

This paper presents an analysis of word-initial glottal stops in Rote and its implications for language revitalization programs. A number of phonological, morphological and syntactic evidence confirms that, in most cases, the status of the initial glottal stops can be determined; some are epenthetic, while others are contrastive. The difference between the two is evident in specific environments. Only a few instances are found in which the data are ambiguous. The data from Rote shows that a unitary analysis of the word-initial glottal stops is not possible. Thus, the status of such glottal stops needs to be carefully considered in orthography design for Rote languages to avoid underrepresentation or overrepresentation, which may lead to issues in the learnability of the orthography. This study contributes to (i) the exploration of variation and universality of prevocalic initial glottal stops, especially in Eastern Indonesian languages, and (ii) the orthography development of languages in Rote and the neighboring languages as an effort to language revitalization.

Molecular and morphological evidence support a new species of Rosaceae Prunus subg. Cerasus from Wuyishan National Park, southeast China

Prunus tongmuensis, a new species of cherry blossom, is described and illustrated from Wuyishan National Park, southeast China. This species is characterized by its tubular to nearly bottle-shaped receptacles and dark purple drupes. It can be distinguished from other wild cherry trees by its flowers and leaves, reddish brown young leaves, presence of 1–2 glands at the base of leaves, petioles densely covered with yellowish brown villi, longer pedicels (0.6–2.5 cm), villous pistil, and dark purple drupes. In the present study, we conducted a comprehensive morphological study based on specimens of the new species and its morphologically close species, field observations, and examination of pollen morphology. In addition, our phylogenetic analysis based on the complete plastid genome sequences further confirms the status of the new species and indicates that it is closely related to Prunus clarofolia, however, it notably differs in leaf shape, size, petiole villus color, gland location, timing of flower and leaf openings, and reflexed or spread sepals, as well as drupe color.

Morphological, phylogenetic, and genomic evidence reveals the causal agent of thread blight disease of cacao in Peru is a new species of Marasmius in the section Neosessiles, Marasmius infestans sp. nov.

The thread blight disease (TBD) of cacao ( Theobroma cacao) in the department of Amazonas, Peru was recently reported to be caused by Marasmius tenuissimus (sect. Neosessiles). This same species is known to be the main causal agent of TBD in West Africa. However, some morphological characteristics, such as the presence of rhizomorphs, the almost exclusively white color, and pileus sizes less than 5 mm, among others, differ to the description of M. tenuissimus. Therefore, we aimed to conduct a taxonomic revision of the cacao-TBD causal agent in Peru, by using thorough micro and macro morphological, phylogenetic, and nuclear and mitochondrial genomic approaches. We showed that the causal agent of TBD of cacao in Amazonas, Peru, belongs to a new species, Marasmius infestans sp. nov. This study enriches our knowledge of species in the sect. Neosessiles, and strongly suggests that the M. tenuissimus species complex is highly diverse.

Three New Species of Laccaria (Hydnangiaceae) from India (Darjeeling Hills) Based on Molecular and Morphological Evidence.

Three new species of Laccaria infundibuliformis, L. pallidus, and L. darjeelingensis, collected from Darjeeling, India, are described based on morphological and molecular evidence. Laccaria infundibuliformis is characterized by its small infundibuliform basidiocarps, and echinulate basidiospores with spines up to 1.36µm long. Laccaria pallidus is characterized by medium-sized greyish-red basidiocarps, and echinulate basidiospores with spines up to 1.9µm long. Laccaria darjeelingensis is characterized by dull red basidiocarps, and echinulate basidiospores with spines up to 1.27µm long. Altogether, the study shows that these three Laccaria species are previously unknown to science.