Set Of Morphological Characters Research Articles

New species of Parapharyngodon (Nematoda: Pharyngodonidae) parasite of Osteocephalus taurinus (Anura: Hylidae) from Northern Brazilian Amazon Region.

Parapharyngodon spp. are nematodes parasites of amphibian and reptiles worldwide distributed. Of 55 valid species, only 11 are known for the Neotropical realm, and six were found parasitizing hylid frogs in the world. In the present work, we describe a new species of Parapharyngodon from the large intestine of Osteocephalus taurinus from Reserva de Desenvolvimento Mamirauá, Amazonas, Brazil, using light and scanning electron microscopy. Parapharyngodon curupira n. sp. is allocated to the group of species with three pairs of cloacal papillae. However, it shows a set of different morphological characters compared to its congeners. In the new species, males have gubernaculum and smooth cloacal lip, females have pre-bulbar ovaries, and we also observed some morphometric differences. Among Parapharyngodon spp. from the Neotropical realm, the new taxon resembles P. alverangai and P. politoedi. The last species was described from the same host and biome (Amazon); however, they can be easily distinguished from new species by the presence of gubernaculum and v-shape structure at the lower caudal lip. Thus, we characterize and propose a new species of Parapharyngodon from the western amazon.

Morphometric analysis provides evidence for two traditionally defined species of the Tillandsia erubescens complex (Bromeliaceae)

Background and aims – A linear morphometric analysis of three taxa of the Tillandsia erubescens complex, composed of T. erubescens var. arroyoensis, T. erubescens var. erubescens, and T. erubescens var. patentibracteata, is presented to evaluate their circumscription. Additionally, their taxonomic rank as varieties or species is discussed considering the obtained results. Geographic distribution, the influence of climate, elevation, and geographic distance on morphological differences between the taxonomic entities is explored.Material and methods – Of a total of 110 herbarium specimens reviewed, 44 were measured. These were previously identified as T. erubescens var. arroyoensis, T. erubescens var. erubescens, or T. erubescens var. patentibracteata. Factor and cluster analyses were performed using 16 quantitative morphological characters. The resulting groups were considered as taxonomic entities supported by morphometric characters, and species distributions were plotted against Mexican biogeographic provinces. A single Mantel test was performed to evaluate the correlation between morphology and climatic variables, elevation, and geographic distance.Key results – The specimens referred to as T. erubescens var. arroyoensis were separated morphometrically from the other two varieties. The most important characters to differentiate T. erubescens var. arroyoensis from T. erubescens var. erubescens were total size, width and length of the leaf sheath and leaf blade, and the number of flowers. The non-overlapping geographical distribution of T. erubescens var. arroyoensis and T. erubescens var. erubescens supports their recognition as independent taxonomic entities. Our study did not support the separation between T. erubescens var. erubescens and T. erubescens var. patentibracteata, which is also reflected by their overlapping geographic distributions. Both precipitation and geographic distance were correlated with the morphological differences among the species.Conclusion – Our morphometric and geographical distribution study supports the recognition of T. arroyoensis and T. erubescens as different species, while no evidence was found to maintain T. erubescens var. erubescens and T. erubescens var. patentibracteata as different taxonomic entities. We provide a set of morphological characters that can be used to distinguish between T. arroyoensis and T. erubescens, including the leaf sheath and leaf blade width, and the number of flowers. Morphological characters agree with the geographic distribution of the studied taxa.

Phylogenetic and morphological analyses of Pilosocereus leucocephalus group s.s. (Cactaceae) reveal new taxonomical implications

Pilosocereus is one of the Cactaceae family’s most relevant genera in terms of the number of species and its wide geographical range in the Americas. Within Pilosocereus, five informal taxonomic groups have been recognized, one of which is P. leucocephalus group s.s., whose phylogenetic relationships remain unresolved. Therefore, our objectives are to recognize the circumscriptions of the species in P. leucocephalus group s.s. and to corroborate the monophyly and phylogenetic relationships of this group through a set of morphological and molecular characters. This study is based on representative sampling along the broad distribution of this group in Mexico and Central America using multivariate and phylogenetic analyses. The morphological characters identified to contribute to species recognition and group formation are branch diameter, areole length, the areole length-width ratio, the distance between areoles, the length of the longest radial spine, and branch and spines colors. The chloroplast markers rpl16, trnL-trnF, and petL-psbE and the nuclear marker AT1G18270 support the monophyly of the P. leucocephalus group s.s., and two probable synapomorphies are suggested, including one transversion in rpl16 and another in petL-psbE. Together, our results demonstrate that sampled species of P. leucocephalus group s.s. encompass six species distributed in Mexico and Central America: P. alensis and P. purpusii in the western region, P. chrysacanthus and P. collinsii in the central region, and P. gaumeri and P. leucocephalus in the eastern region. A taxonomic key to recognized species is provided.

Morphology and morphometry of pharyngeal bone and teeth in cyprinid species from the Kurdistan Region, Iraq

The morphology of pharyngeal bones and teeth was determined on seven cyprinid species caught from the Greater Zab River, a tributary of Tigris River, located in the northern part of Iraq in the Kurdistan Region. Eleven morphological characters of the pharyngeal bone and teeth were identified, measured and compared from photographs of the 152 individual species collected. The relationship between pharyngeal bone total length and four-dimensional measurements of the pharyngeal bone were determined using linear regression and multivariate analysis. Results show bone characteristics of the studied species are distinctly different in terms of shape, tooth number, tooth formulae and dimensions of the pharyngeal bones. Regression analysis shows positive coefficients of TL with all parameters PL, DL, PW and DP while multivariate linear discriminate analysis shows distinct groupings of each species using non-dimensional measurements of the bone characters. The measurements gathered and application of biometric relationships to ease the identification of the cyprinid species contributes to the morphological information on cyprinid species in a data deficient region of the world. This work provides a new set of morphological characters of the pharyngeal bone and teeth of the seven cyprinid species from Northern Mesopotamia that may enable their separation from the members of their cyprinid genera.

Molecular phylogeny of Nipponacmea (Patellogastropoda, Lottiidae) from Japan: a re-evaluation of species taxonomy and morphological diagnosis.

The patellogastropod limpet genus Nipponacmea is widely distributed in Japan and adjacent East Asia. Species identification within Nipponacmea is challenging due to the high variation in shell morphology. In this study, we examined the taxonomy of this genus represented by nine nominal species from 43 localities (including type localities). Results of the molecular phylogenetic analysis revealed that: (1) N.gloriosa, the sole species in this genus inhabiting the subtidal zone, represents the most basal independent branch; (2) the remaining species are divided into two large clades with lower- and higher-apex shell profiles; and (3) the high-apex morphology was derived from the low-apex type. The terminal clades defined using the molecular data were consistent with nine morphospecies and had 100% bootstrap values, strongly supporting the conventional taxonomy of Nipponacmea. Although morphological similarities do not always reflect phylogeny, the set of morphological characters used in the current taxonomy were proven to be adequate for diagnosis. In conclusion, this study provided solid evidence to uphold the monophyly of known species of Nipponacmea in Japan and demonstrated the usefulness of morphological characters for species diagnosis.

Does sexual size dimorphism vary with female size in forest millipedes Centrobolus Cook, 1897?

This study aimed to determine whether the variation responsible for breaking Rensch's Rule when Sexual Size Dimorphism (SSD) increased with body size was due to male-biased or female-biased variation by studying a sex-based set of morphological characters. Variation in female volume based on length and width measurements was associated with the SSD in the forest millipede genus Centrobolus. There was a significant positive correlation between SSD and female size (r=0.56, Z score=2.76, n=22, p

Evidence for extensive hybridisation and past introgression events in feather grasses using genome-wide SNP genotyping

BackgroundThe proper identification of feather grasses in nature is often limited due to phenotypic variability and high morphological similarity between many species. Among plausible factors influencing this issue are hybridisation and introgression recently detected in the genus. Nonetheless, to date, only a bounded set of taxa have been investigated using integrative taxonomy combining morphological and molecular data. Here, we report the first large-scale study on five feather grass species across several hybrid zones in Russia and Central Asia. In total, 302 specimens were sampled in the field and classified based on the current descriptions of these taxa. They were then genotyped with high density genome-wide markers and measured based on a set of morphological characters to delimitate species and assess levels of hybridisation and introgression. Moreover, we tested species for past introgression and estimated divergence times between them.ResultsOur findings demonstrated that 250 specimens represent five distinct species: S. baicalensis, S. capillata, S. glareosa, S. grandis and S. krylovii. The remaining 52 individuals provided evidence for extensive hybridisation between S. capillata and S. baicalensis, S. capillata and S. krylovii, S. baicalensis and S. krylovii, as well as to a lesser extent between S. grandis and S. krylovii, S. grandis and S. baicalensis. We detected past reticulation events between S. baicalensis, S. krylovii, S. grandis and inferred that diversification within species S. capillata, S. baicalensis, S. krylovii and S. grandis started ca. 130–96 kya. In addition, the assessment of genetic population structure revealed signs of contemporary gene flow between populations across species from the section Leiostipa, despite significant geographical distances between some of them. Lastly, we concluded that only 5 out of 52 hybrid taxa were properly identified solely based on morphology.ConclusionsOur results support the hypothesis that hybridisation is an important mechanism driving evolution in Stipa. As an outcome, this phenomenon complicates identification of hybrid taxa in the field using morphological characters alone. Thus, integrative taxonomy seems to be the only reliable way to properly resolve the phylogenetic issue of Stipa. Moreover, we believe that feather grasses may be a suitable genus to study hybridisation and introgression events in nature.

Identification and characterization of hybrids of Acipenser ruthenus and Acipenser baerii (Actinopterygii, Acipenseriformes) from the Irtysh River

Two sturgeon species, Acipenser ruthenus (Linnaeus, 1758) and Acipenser baerii (Brandt, 1869), inhabit the Irtysh basin. In 2018, we received some “atypical” specimens of sturgeon, which were similar to A. ruthenus but had a number of pronounced external differences. The hybrids A. ruthenus × A. baerii, named “oster”, can sometimes be caught in natural habitats in the Ob and the Yenisei rivers. Despite the development of methods for the genetic identification of sturgeons, the molecular genetic characteristics of the hybrids of A. baerii and A. ruthenus have not been carried out. The purpose of this study is to develop a complex of morphological and genetic characters to identify the hybrid of A. ruthenus and A. baerii from the Irtysh River. We used a complex of morphological and genetic methods to compare the putative hybrids with parental species The putative hybrids were similar to A. ruthenus in the number of dorsal scutes, the number of rays in the dorsal and anal fins, the structure of stamens on the first gill arch, and the presence of fringe on the tendrils. The hybrids were similar to A. baerii in size and weight values, the structure of dorsal scutes, the number of lateral and ventral scutes, and the number of gill rakers on the first gill arch. Genotyping of putative hybrids by using the Inter Simple Sequence Repeat (ISSR) markers revealed the presence of sites characteristic of both parental species. The fragment of the control region of mitochondrial DNA in the hybrids matched to that of A. baerii that allowed us to identify females of A. baerii as maternal individuals of the hybrids. Possible causes and factors promoting interspecific hybridization of A. ruthenus and A. baerii were studied. This is the first described fact of the appearance of sturgeon hybrids in the Ob-Irtysh basin. It is necessary to continue monitoring studies to identify the number of these hybrids in the ecological system of the Irtysh River. The data set of morphological characters and genetic methods can be used to identify the hybrids of A. ruthenus and A. baerii.

Integrative taxonomy reveals a new genus from Central Chile and suggests a systematic rearrangement in Stenochiinae (Coleoptera: Tenebrionidae)

AbstractStenochiinae is a subfamily of Tenebrionidae with a mainly pantropical distribution, but with a few species distributed at higher latitudes. In general, Stenochiinae has been little studied, and the taxonomic effort been insufficient to understand all its diversity. Recently, a new taxon of Stenochiinae from Central Chile with remarkable morphological characters was collected. Based on phylogenetic analyses of concatenated 28S, 18S, 16S and COI genes and on morphological analyses, a new genus and two species of Stenochiinae are described from Central Chile. Our results suggest that Nestorinus gen. nov. (with the species Nestorinus roitmani sp. nov. and Nestorinus yanettae sp. nov.) has a basal position in Stenochiinae, related to Homocyrtus. The set of morphological characters shared between Stenochiini and Cnodalonini plus their phylogenetic position make it difficult to classify them at tribal level.

<p><strong>Taxonomic position and circumscription of Cardamine barbaraeoides (Brassicaceae), a systematically challenging taxon from the Balkan Peninsula</strong></p>

The Balkan Peninsula, and the territory of Greece in particular, is a significant biodiversity hotspot in the Mediterranean that is rich in endemic plants. The focal species of this study, Cardamine barbaraeoides, is a narrow Greek endemic that has been confused taxonomically since its original description. Based on a detailed multivariate morphometric study, we provide here a set of morphological characters that enables the reliable identification of this species. In addition, we present an identification key to C. barbaraeoides and related taxa. We have revised herbarium specimens and literature data on the occurrence of this species in Greece and ascertained that it occurs only in the Pindos mountains (the Southern Pindos and partly the Northern Pindos floristic regions). All reports of this species from the Greek floristic regions of North Central, Sterea Ellas and partly also Northern Pindos were based on misidentifications of specimens of C. acris.

A new cryptic species of yellow-eared bat Vampyressa melissa species complex (Chiroptera: Phyllostomidae) from Colombia

Abstract The Vampyressa melissa species complex comprises three rare bat species poorly represented in museum collections. Vampyressa melissa and V. sinchi are restricted to the eastern slope of the Andes, while V. elisabethae only is known from Panama, in Central America. The species complex has received recent attention in terms of systematic reviews, which concluded in the description of two species: one from Panama (V. elisabethae) and one from Colombia (V. sinchi). Vampyressa melissa recently was reported from the eastern slopes of the Cordillera Oriental of Colombia, in the department of Casanare. However, morphological and genetic (Cytochrome b) comparisons showed that these specimens belong to an undescribed species of the genus. The new species is the smallest member of the V. melissa complex and has a unique set of morphological characters compared to other Vampyressa species. Molecular evidence shows that the new species is sister to V. melissa (sensu stricto) from Colombia and Peru, albeit with high genetic divergence (7.9%). Nevertheless, Cytochrome b sequences of V. elisabethae and V. sinchi still are unknown. This new species increases to six the number of species in the genus. Vampyressa melissa, V. sinchi, and the new species, exhibit restricted distributions in the eastern slopes of the Andean Cordillera, in specific altitudinal ranges. Because of geographic constraints, their biological rarity, and the high deforestation rates in their distributional area, we suggest that these three species must be considered as taxa threatened with extinction.

A new species of Aplectana (Nematoda: Cosmocercidae) in the Marsupial frog Gastrotheca microdiscus (Amphibia: Hemiphractidae) from Brazil.

Aplectana longa n. sp. (Ascaridida: Cosmocercidae) from the small intestine of Gastrotheca microdiscus (Amphibia: Hemiphractidae) is described and illustrated. The new species is characterized by the combination of a unique set of morphological characters: 1) Large body size in both sexes; 2) Lateral alae absent; 3) Gubernaculum present, small, thin, weakly sclerotized, pointed at the distal end and curved proximally at the end, with a small and punctiform papilla-like dilation, and 4) Caudal papillae arrangement (9+1:0:6). The distribution pattern of caudal papillae is similar only to Aplectana chamaeleonsis. Nevertheless, Aplectana longa n. sp. is easily differentiated from this species by the arrangement of precloacal papillae. This is the 57th species of the Aplectana and the 16th species reported from Brazil.

A new species of Syzygium (Myrtaceae) from the Bird’s Head Peninsula, western New Guinea

Syzygium oransbariense Mustaqim, Y.W.Low & Heatubun (Myrtaceae) is here formally described. This species is found in the lowlands on the eastern flank of the Arfak Mountains, Bird’s Head Peninsula, western New Guinea. The species is similar to Syzygium longipes (Diels) Merr. & L.M.Perry, but differs based on a set of diagnostic morphological characters. Species description, distribution, a preliminary conservation status assessment, and notes on the new species are presented here.

A new species of Sphaerotheca Günther, 1859 (Anura: Dicroglossidae) from the degraded urban ecosystems of Bengaluru, Deccan Plateau, India.

The dicroglossid genus Sphaerotheca was erected by Günther in 1859, with its range of distribution in South Asia. Since then, 13 species have been described and 10 species are considered valid. Many of these descriptions were from low to mid-elevation ranges of homestead areas, agroecosystems and degraded landscapes with a few from forested areas. In the present account, a new species of Sphaerotheca, a genetically distinct lineage with a morphological character set distinguishable from its congeners, is described from the surroundings of Bengaluru city, India. Based on evidence for the origin of the original specimen, we also designated a neotype for Rana variegata Gravenhorst, 1829, a junior primary homonym of Rana variegata Linnaeus, 1758, and permanently invalid name, so that it is now a subjective synonym of Rana (Tomopterna) breviceps rolandae Dubois, 1983.

A multivariate morphometric analysis of diagnostic traits in southern Italy and Sicily pubescent oaks

Species identification within the species complex of Q. pubescens is a well-known taxonomic challenge among European botanists. Some of the specific pubescent oak binomials currently accepted in various European floras and checklists were originally described in Sicily and southern Calabria. As a consequence, several species belonging to the pubescent oaks group (Q. pubescens, Q. amplifolia, Q. congesta, Q. dalechampii, Q. leptobalana and Q. virgiliana) are reported in the taxonomic and phytosociological literature. To verify whether it was possible to associate a diverse set of morphological characters with each of these different taxa, thirteen natural populations of pubescent oak from Sicily and southern Calabria were sampled. A total of 391 trees, 3,887 leaves and 1,047 fruits were collected. Overall, 28 morphological characters of oak leaves and fruits were statistically analysed using univariate and multivariate procedures. The results showed that neither the groups of morphological diversity identified by cluster analysis, nor those obtained by our expert identification through the use of analytical keys, matched with the current taxonomical frameworks as proposed by the most recent floras and checklists. Nearly all of the morphological characters considered displayed a more or less continuous trend of variation, both within and among populations. In the light of these findings it seems unlikely that more than one biological species of pubescent oak occurs in Sicily and southern Calabria.

Phylogenetic analysis of the Euschistus group (Hemiptera: Pentatomidae) suggests polyphyly of Dichelops Spinola, 1837 with the erection of Diceraeus Dallas, 1851, stat. rev.

AbstractCarpocorini are the most diverse tribe within Pentatominae, comprising about 100 genera and 500 species, with the highest diversity found in the Neotropics. Within Carpocorini, some groups of genera have been, formally or informally, proposed based on morphological similarities and taxonomic history. The Euschistus group was informally proposed and comprises 20 genera, including Euschistus Dallas, 1851 and Dichelops Spinola, 1837. Both of these genera had their monophyly under dispute recently. Dichelops, which includes the species commonly known as the green‐belly stink bug, comprises 16 species in three subgenera, with an exclusively Neotropical distribution. The genus was revised recently, and for each subgenus, a set of distinct morphological characters was listed, which allow their precise identification. We tested the monophyly of the Euschistus group and of Dichelops under parsimony criteria using discrete and continuous characters and two‐character weighting methods. The Euschistus group was paraphyletic, and Dichelops was polyphyletic in every analysis, and the taxonomic characters formerly proposed as diagnostic for the genus and its subgenera were homoplastic. On the basis of the phylogenetic result, we propose the erection of Diceraeus Dallas, 1851, stat. rev. to the status of genus and Dichelops comprising two subgenera, the nominal and Prodichelops Grazia, 1978. This decision has implications for applied entomology, because species of Diceraeus are important crop pests in the Neotropics.

Entomoneis annagodhei sp. nov., a new marine diatom (Entomoneidaceae, Bacillariophyta) from the west coast of Sweden

The genus Entomoneis includes diatoms with an elevated bilobate keel, a sigmoid raphe canal and numerous girdle bands. It is known to inhabit various environments, from freshwater to marine, both plankton and benthos. During a phytoplankton investigation in the Kungälv estuary on the west coast of Sweden, we observed numerous cells belonging to Entomoneis. Further morphological investigations performed with light and electron microscopy allowed us to describe Entomoneis annagodhei, sp. nov., with a unique set of morphological characters. Most importantly, a still undocumented character proved to be an oblique transapical fascia across the centre of the valve. Other distinctive features of this species are a pronounced raphe canal with dense raphe fibulae, very fine striation, resolvable only with electron microscopy, external lanceolate slit-like opening of the central nodule, and fine, linear to undulate external ridges running more or less parallel and adjacent to the raphe and valve margin. The morphological characters and morphometry are discussed in comparison with similar taxa. Our results contribute to the under-appreciated diversity of Entomoneis, especially inhabiting the marine plankton.

Integrative taxonomy revisits the ontogeny and trophic niches of Rimicaris vent shrimps.

Among hydrothermal vent species, Rimicaris exoculata is one of the most emblematic, hosting abundant and diverse ectosymbioses that provide most of its nutrition. Rimicaris exoculata co-occurs in dense aggregates with the much less abundant Rimicaris chacei in many Mid-Atlantic Ridge vent fields. This second shrimp also houses ectosymbiotic microorganisms but has a mixotrophic diet. Recent observations have suggested potential misidentifications between these species at their juvenile stages, which could have led to misinterpretations of their early-life ecology. Here, we confirm erroneous identification of the earliest stages and propose a new set of morphological characters unambiguously identifying juveniles of each species. On the basis of this reassessment, combined use of C, N and S stable isotope ratios reveals distinct ontogenic trophic niche shifts in both species, from photosynthesis-based nutrition before settlement, towards a chemosynthetic diet afterwards. Furthermore, isotopic compositions in the earliest juvenile stages suggest differences in larval histories. Each species thus exhibits specific early-life strategies that would, without our re-examination, have been interpreted as ontogenetic variations. Overall, our results provide a good illustration of the identification issues persisting in deep-sea ecosystems and the importance of integrative taxonomy in providing an accurate view of fundamental aspects of the biology and ecology of species inhabiting these environments.

Taxonomic assessment and distribution of common toads (Bufo bufo and B. verrucosissimus) in Turkey based on morphological and molecular data

Abstract The Bufo bufo species group includes four species distributed in the western Palearctic: B. bufo, B. eichwaldii, B. spinosus and B. verrucosissimus. Both B. bufo and B. verrucosissimus are known to occur in Turkey, but their range boundaries and the taxonomic status of B. verrucosissimus are still uncertain. In this study, we analyzed the variation in a set of morphological characters and in two mitochondrial and two nuclear DNA markers to address these questions. Phylogenetic analyses of sequence data support two main clades of common toads in Turkey, corresponding to B. bufo and B. verrucosissimus. The latter is subdivided into two allopatric subclades including populations along the Mediterranean and Black Sea coast, respectively. Discriminant analysis of morphological data showed separation among groups as defined by molecular analyses. We discuss these results and their implications for the evolutionary history of common toads in Turkey.

Reviewing the identity of the Maltese Polypodium (Polypodiaceae) – new evidence from morphology and flow cytometry

The first record of Polypodium from Gozo (Maltese Islands) was described as a new endemic taxon, Polypodium vulgare subsp. melitense, based on its unique set of morphological characters. It was treated as a novelty and designated as a subspecies of P. vulgare mainly due to the lack of paraphyses, the presence of 10–16 annular cells, and a mean spore length of 64 μm. The fern was reassessed by us employing a more rigid morphological analysis and the application of flow cytometry. The absence of paraphyses was confirmed, but the number of annular cells (5–11) and the spore length (70–79 μm) differed from the previous study. These and other morphological traits, the phenology (leaf-shedding in spring), the calcareous growth habitat, and the southern distribution implied that the fern is P. cambricum. Final confirmation was obtained from flow cytometry; the genome size of 17 pg corresponds perfectly with the range obtained for other accessions of this diploid species. The Polypodium reported from Malta does not merit taxonomic distinction despite being a rare form of P. cambricum, which lacks paraphyses.