Morphological Characters Research Articles

Devonian Harpetidae from the central and eastern Anti–Atlas, Morocco

Devonian Harpetidae from the central and eastern Anti–Atlas, Morocco

Distribution and genetic diversity of cobitid species in Iran (Teleostei: Cobitidae)

Several species of Cobitis have been reported within Iran, but only four are recognized as valid. The geographical distribution and genetic diversity of these species are not well-known. Two new populations of C. saniae and C. avicennae were reported herein based on their morphological and phylogenetic characters from the Mahabad River, a tributary of the Urmia Lake basin, and the Razavar River, a tributary of the Karkheh drainage, respectively. The genetic diversity and genetic structure of populations of C. saniae, C. avicennae, and C. faridpaki were analysed using the DNA sequences of the mitochondrial COI gene. COI sequences from various watersheds in Iran, Azerbaijan, and Georgia were used. A moderate to high level haplotype diversity and low nucleotide diversity were found in most of the populations of all three species. The AMOVA test and pairwise FST comparison revealed significant genetic structure and genetic distance between the Urmia Lake basin and other C. saniae populations. The results highlight the importance of conserving these species and their habitats, particularly in the Urmia Lake basin, where significant genetic differentiation was observed.

Genetic Divergence and Evolutionary Adaption of Four Wild Almond Species (Prunus spp. L.)

Parallel evolution usually occurs among related species with similar morphological characters in adaptation to particular environments. Four wild almond species (Prunus) sharing the character of dry mesocarp splitting are distributed in China, most of which occur in arid Northwestern China. In the present study, we aimed to clarify the phylogenetic relationship, evolutionary history, and environmental adaptation of these wild almond species based on genome-wide SNP data and chloroplast genomes. Chloroplast phylogeny showed P. pedunculata and P. tenella were clustered with wild cherry species (Prunus), while P. mongolica and P. tangutica were clustered with wild peach species (Prunus). Genomic phylogeny suggested P. tenella formed an independent clade. An ABC-RF approach showed P. pedunculata was merged with P. tenella and, then, diverged from the ancestor of P. mongolica and P. tangutica. P. tenella was split from other wild almond species at ca. 7.81 to 17.77 Ma. Genetic environment association analysis showed precipitation variables contributed the most to genetic variations between P. mongolica from an arid environment and P. tangutica from a humid environment. Finally, a total of 29 adaptive loci were successfully annotated, which were related to physiological processes in response to abiotic stresses. Inconsistent genomic and chloroplast phylogenetic positions of P. tenella suggested this species could have originated from historical hybridization among different clades of Prunus. Physiological mechanisms promoted P. mongolica in adapting to the arid environment in Northwestern China.

Pseudochroaptomus ecuadoriensis—a new genus and species of Philonthina and its systematic placement (Coleoptera: Staphylinidae: Staphylininae)

Pseudochroaptomus ecuadoriensis Chani-Posse et al., a new genus and species of the subtribe Philonthina (tribe Staphylinini) from the Tropical Andes of Ecuador, is described and illustrated. A dataset of 35 morphological characters scored for 23 taxa representing main clades of Philonthina, with focus on the Neotropical lineage and its subclades was prepared and analysed by maximum parsimony and Bayesian inference. Both analytical methods unambiguously placed Pseudochroaptomus as the sister-group of Chroaptomus Sharp.

Phenotypic convergence is more frequent and stronger in herbivorous freshwater fishes.

Constraints on phenotypic evolution can lead to patterns of convergent evolution, by limiting the 'pool' of potential phenotypes in the face of endogenous (functional, developmental) or exogenous (competition, predation) selective pressures. Evaluation of convergence depends on integrating ecological and morphological data within a robust, comparative phylogenetic context. The staggering diversity of teleost fishes offers a multitude of lineages adapted for similar ecological roles, and therefore, offers numerous replicated evolutionary experiments for exploring phenotypic convergence. However, our understanding of fish feeding systems has been primarily shaped by marine species, with the monolithic exception of freshwater cichlids. Here we use piranhas and pacus (Serrasalmidae) to explore the evolution of different feeding ecologies and their morphological proxies in Neotropical freshwater environments. Specifically, we explore whether convergence is more widespread among plant-eating fishes, arising from strong constraints on phenotypic evolution in herbivores. Using osteological micro-computed tomographic imaging (μCT), we describe the major axes of morphological variation in pacus and piranhas, regarding their diet and feeding behaviors. Next, we evaluated whether herbivorous niches are less labile than other dietary guilds and whether herbivorous species' phenotypes evolve at a slower evolutionary rate than other taxa. We then assess how convergent herbivorous taxa are, using three different suites of morphological characters (dental, jaw, and abdominal morphometrics). Ecologically, herbivory is not a dead end, exhibiting similar observed transition rates as those between carnivores and omnivores. However, we documented widespread convergence in herbivores and that herbivores have slower rates of phenotypic evolution than carnivores. Most instances of convergence are found in herbivorous taxa, specifically in frugivores and folivores. Moreover, instances of 'complete' convergence, indicated by positive convergence metrics observed in more than one morphometric dataset, were only found in herbivores. Herbivores do appear to evolve under constrained circumstances, but this has not limited their ecological lability.

Scale morphology variability in cyprinid fishes and its significance in taxonomy using light and scanning electron microscopy: A case study of the genus Garra Hamilton, 1822 (Teleostei: Cyprinidae).

To evaluate scale morphological variability (shape, size, topological macro- and microstructures, ornamentation patterns) of cyprinid fishes, nine species of the genus Garra were selected and their scales from five different body regions were studied by using light and scanning electron microscopy. The scales of the examined species were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. In addition to these typical characteristics, some morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, ovoid), and the focus shape. These variations were mainly dependent on the fish lengths and the flank region. Morphological analysis clustered the examined species into two distinct groups. Group I consisted of G. amirhosseini and G. gymnothorax, while Group II has three subgroups, which include G. persica and G. mondica (subgroup I), G. meymehensis, G. rossica, G. nudiventris, G. hormuzensis (subgroup II), and G. rufa (subgroup III). The grouping of the studied Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris. In addition, in the phylogenetic tree, G. persica, G. mondica, G. amirhosseini, and G. hormuzensis formed a distinct clade. However, these species did not represent close relationships in the dendrogram obtained from the scale morphology. A possible explanation why the grouping of the studied Garra species based on their scale morphological characters does not match their phylogenetic relationships is that most of the scale morphological traits vary depending on the fish size and the location of the scales on the flank. Therefore, except for some traits, that is, central or antero-centrally positioned focus, having no cteni, a specific sectioned form so called "tetra-sectioned" type, the other examined variables are not useful enough to be used in the taxonomic study of the examined cyprinid fishes. Therefore, scale morphological characters should be used carefully for taxonomic purposes. RESEARCH HIGHLIGHTS: Shape, size, topological macro- and microstructures, and ornamentation patterns of nine species of the genus Garra were studied by using light and scanning electron microscopy. The scales were thin with a central or antero-centrally positioned focus, with no cteni in the posterior part. Morphological variation was observed in the overall shape (irregular round, true oval, round-triangular, irregular pentagonal, hexagonal, irregular hexagonal, pentagonal, and ovoid), and the focus shape. The grouping of Garra species based on the current scale morphological characters and the molecular data was only consistent for G. rossica and G. nudiventris.

Integrative species delimitation and five new species of lynx spiders (Araneae, Oxyopidae) in Taiwan.

An accurate assessment of species diversity is a cornerstone of biology and conservation. The lynx spiders (Araneae: Oxyopidae) represent one of the most diverse and widespread cursorial spider groups, however their species richness in Asia is highly underestimated. In this study, we revised species diversity with extensive taxon sampling in Taiwan and explored species boundaries based on morphological traits and genetic data using a two-step approach of molecular species delimitation. Firstly, we employed a single COI dataset and applied two genetic distance-based methods: ABGD and ASAP, and two topology-based methods: GMYC and bPTP. Secondly, we further analyzed the lineages that were not consistently delimited, and incorporated H3 to the dataset for a coalescent-based analysis using BPP. A total of eight morphological species were recognized, including five new species, Hamataliwa cordivulva sp. nov., Hamat. leporauris sp. nov., Tapponia auriola sp. nov., T. parva sp. nov. and T. rarobulbus sp. nov., and three newly recorded species, Hamadruas hieroglyphica (Thorell, 1887), Hamat. foveata Tang & Li, 2012 and Peucetia latikae Tikader, 1970. All eight morphological species exhibited reciprocally monophyletic lineages. The results of molecular-based delimitation analyses suggested a variety of species hypotheses that did not fully correspond to the eight morphological species. We found that Hamat. cordivulva sp. nov. and Hamat. foveata showed shallow genetic differentiation in the COI, but they were unequivocally distinguishable according to their genitalia. In contrast, T. parva sp. nov. represented a deep divergent lineage, while differences of genitalia were not detected. This study highlights the need to comprehensively employ multiple evidence and methods to delineate species boundaries and the values of diagnostic morphological characters for taxonomic studies in lynx spiders.

A preliminary study of the morphological variation of rhizomes in Zingiber Mill. and its role in taxonomy

The rhizomes of Zingiber are highly diverse and have potential in taxonomy, but their fundamental structure has never been properly understood in connection with an understanding of the sympodial growth form of the whole plant. This study is based on a literature review and on observations of fresh materials of 32 Zingiber species mainly from China, representing all four sections of the genus. An analysis of the sympodial modular growth habit of these plants has recognised that both isomodular and heteromodular growth exist within the genus. The study shows that rhizomes of Zingiber are highly-organised, compound, sympodial structures. By introducing the term rhizome unit, Zingiber rhizomes can be meaningfully described by depicting the morphology of the rhizome units and the relative arrangement of these units to one another. Six morphological attributes of rhizome units (shape, size, direction of growth, colour and number of nodes per rhizome, and length of internodes) and two attributes of their relative arrangement to one another (dorsiventral vs lateral position of rhizome units and the ramification position along the length of rhizome unit) are discussed. A preliminary assessment of variation patterns and the taxonomic value of these characters are presented. Together, these attributes contribute to the overall morphology of rhizomes. The relationship between rhizome structure and the above-ground clumping habit is discussed. The term pseudo-neck is coined to refer to the narrowed basal part that occurs in the rhizome units of some Zingiber species while the thick apical part of rhizome units where the internodes are often shorter than those on the pseudo-neck is called head. Problems with existing terminology for rhizome and plant habit descriptions in Zingiber are highlighted. This study suggests that whether the plane of distichy of leaves is parallel or perpendicular to the rhizome unit, a key character that many previous studies used for subdivision of Zingiberaceae, needs re-assessment, because in Zingiber both states of the character exist. Characters of rhizome morphology of the four sections in Zingiber are discussed, but studies of a larger number of species are needed to better-assess the relevance of these characters to the infrageneric classification of the genus. Schematic illustrations and colour plates of rhizomes from representative species are provided to assist the descriptions and discussions. It is hoped that this preliminary study will facilitate and encourage more comprehensive studies of rhizomes of Zingiber and of other genera within Zingiberaceae. Such work will lead to a better understanding of these structures and help establish a more comprehensive and accurate terminology for them, which in turn will facilitate the taxonomy and identification of the family.

Another new micro-endemic, limestone-dwelling leaf-toed gecko (Gekkonidae: Dixonius) from Phetchaburi Province, western Thailand

We describe Dixonius chotjuckdikuli sp. nov. from Khao Ebid (Mount Ibit), Khao Yoi District, Phetchaburi Province, western Thailand. The new, limestone-dwelling species differs from all currently recognized species of Dixonius by the following combination of morphological characters and pattern: maximal known snout-vent length of 45.6 mm, 18 (rarely 16) longitudinal rows of dorsal tubercles; 31 to 34 paravertebral scales; 18 (rarely 16) longitudinal rows of ventral scales across the abdomen; 20 to 22 interciliary scales; 5 or 6 precloacal pores in males, no pores in females; a marked canthal stripe extending beyond the shoulder; and a blotched dorsal pattern in males, females and juveniles. This description brings the number of Dixonius species to 17, among which seven species are endemic to Thailand.

A revised tribal classification of Papaveraceae (poppy family) based on molecular and morphological data

AbstractPapaveraceae, commonly known as the poppy family, contains many species with horticultural and/or pharmaceutical importance and has been the subject of various molecular studies. However, a widely accepted tribal classification for Papaveraceae remains lacking. In this study, we used a sampling covering all 48 of the currently recognized genera of Papaveraceae. Our study is to employ broad morphological data in combination with sequence data from two nuclear and seven plastid DNA regions to reconstruct phylogenetic relationships within the family. Our analyses indicate that Pteridophylloideae is sister to the clade containing Hypecooideae and Fumarioideae, and these three lineages are in turn sister to Papaveroideae. The alternative topologies constraining Pteridophylloideae as sister to the other poppy species, to Papaveroideae or to Hypecooideae, as recovered in previous studies, are all rejected. Fumarioideae contains nine main clades, and Fumarieae is nested in traditional Corydaleae. Within Papaveroideae, three main clades are recovered and Platystemoneae is embedded within traditional Papavereae. Both topologies constraining traditional Corydaleae or Papavereae as monophyletic are significantly rejected. Within this phylogenetic framework, the evolution of selected characters is inferred and diagnostic morphological characters at different taxonomic levels are identified and discussed. Based on morphological and molecular evidence, a new tribal classification of Papaveraceae is presented, in which 4 subfamilies, 14 tribes (including 7 newly described tribes), and 43 genera are recognized.

Description of a new species of Cottus Linnaeus (Cottidae) from the Western Dvina / Daugava River system, Baltic Sea basin, based on integrative taxonomy

In the genus Cottus (family Cottidae), 72 species are known. Of these, 37 species are found in North America, 17 in Asia, and 18 in Europe. Over the past 18 years, nine new species have been described from Western and Central Europe, two from Eastern part of this continent. Also, the validity of two Eastern European species was confirmed. In the Western Dvina / Daugava River system (Baltic Sea basin), Cottus dorofeevi sp. nov. was found. To describe this species, an integrative approach was used that combines morphological and molecular methods. The new species differs from other species of the genus Cottus by a combination of morphological characters. Taxonomically the most conspicuous features are: flattened shape of head; long pelvic fins (reaching anus); incomplete trunk canal of lateral line with 25-27 pores; presence of melanophores on ventral side of body and fins. Genetically, C. dorofeevi sp. nov. is sister to C. koshewnikowi. Haplotypes (CR) of C. dorofeevi sp. nov. are differentiated from haplotypes of other European species of the genus Cottus by genetic distances between 1.3% and 3%.

Genomic analyses reveal the stepwise domestication and genetic mechanism of curd biogenesis in cauliflower.

Cauliflower (Brassica oleracea L. var. botrytis) is a distinctive vegetable that supplies a nutrient-rich edible inflorescence meristem for the human diet. However, the genomic bases of its selective breeding have not been studied extensively. Herein, we present a high-quality reference genome assembly C-8 (V2) and a comprehensive genomic variation map consisting of 971 diverse accessions of cauliflower and its relatives. Genomic selection analysis and deep-mined divergences were used to explore a stepwise domestication process for cauliflower that initially evolved from broccoli (Curd-emergence and Curd-improvement), revealing that three MADS-box genes, CAULIFLOWER1 (CAL1), CAL2 and FRUITFULL (FUL2), could have essential roles during curd formation. Genome-wide association studies identified nine loci significantly associated with morphological and biological characters and demonstrated that a zinc-finger protein (BOB06G135460) positively regulates stem height in cauliflower. This study offers valuable genomic resources for better understanding the genetic bases of curd biogenesis and florescent development in crops.

Morphological and Molecular Characters Differentiate Common Morphotypes of Atlantic Holopelagic Sargassum

Since 2011, massive new strandings of holopelagic Sargassum have been reported on the coasts of the Caribbean, northern Brazil, Guiana, and West Africa, causing severe economic and ecological damage. Three common morphotypes (S. fluitans III, S. natans I, and S. natans VIII) were identified as responsible for these catastrophic events, with dominance shifts between them over time. However, the taxonomic status of these holopelagic Sargassum morphotypes remains unclear. Using an integrative taxonomy framework, combining a morphological study and molecular analyses, this study aimed to clarify their taxonomic status. Morphological analyses of 54 characters revealed no intermediate form between the three morphotypes, with the overall shape, nature of the axis, and size and shape of blades and vesicles being the most discriminating. An analysis of mitochondrial (IGS, cox2, cox3, mt16S rRNA, and nad6) and plastid (rbcL) markers confirmed the genetic divergence among the three morphotypes, with a lower level of divergence between the two S. natans morphotypes. Without additional molecular characterization, these morphotypes cannot be classified as three distinct species. However, due to their distinct morphological characteristics and sympatry within drifting aggregations, a revision of holopelagic species names is proposed, with Sargassum fluitans var. fluitans (for S. fluitans III), Sargassum natans var. natans (for S. natans I), and S. natans var. wingei (for S. natans VIII). This revision provides necessary clarity on the species involved in inundations of the tropical Atlantic.

A new species of genus Urophonius Pocock, 1893 (Scorpiones, Bothriuridae), from Andean Mauline Chilean forests, with a phylogenetic re-analysis of the genus

Urophonius trewankesp. nov. is described from the Mauline Andean woods of northern Chilean Patagonia. This species belongs to the granulatus species group, which includes the most basal species within the genus. This species is only active in summer as in all species of its group. We performed a phylogenetic analysis of the genus Urophonius based on morphological characters to establish the position and relationships of the new species in the genus.

Redescription of Astylus atromaculatus (Blanchard, 1843) a taxonomic contribution to the Neotropical species of the genus Astylus (Coleoptera: Melyridae)

Astylus atromaculatus (Blanchard, 1843), the most widely distributed taxon of the genus, is redescribed. The original description is based mainly on the coloration patterns of the elytra. The study of the external morphological characters and genitalia of the type material and from specimens of collections allows the establishment of a new synonymy between A. atromaculatus and A. atromaculatus var. duodecimmaculatus. Geographic distribution data is provided for the taxon are provided.

A New Species of Zanthoxylum (Rutaceae) from the Brazilian Cerrado

A New Species of Zanthoxylum (Rutaceae) from the Brazilian Cerrado

Old World species of Trichanthecium (Poaceae: Panicoideae: Paniceae) including a new species from the Democratic Republic of Congo

Studies of African material of the tribe Paniceae (Poaceae) resulted in the transfer of 12 species from Panicum, the description of a new species, and the conclusion that the genus Trichanthecium now consists of 52 species. The new Trichanthecium delimitation was confirmed by phylogenetic studies based on chloroplast ndhF and rbcL sequences. Morphological and anatomical characters are discussed within their pylogenetic context. A new species is described: T. marunguensis. Lectotypes are designated for Panicum aequinerve, P. calvum, P. chionachne, P. hochstetteri var. glaberrimum, P. inaequilatum, P. lepidum, P. mokaense, and P. wiehei. The following new combinations are proposed: T. acrotrichum, T. aequinerve, T. calvum, T. chionachne, T. delicatulum, T. eickii, T. hochstetteri, T. inaequilatum, T. perrieri, T. pusillum, T. striatissimum, and T. wiehei. Full synonymies, descriptions, distribution and habitat information, citation of all specimens and a key to the Old World species of the genus are provided; seven species are illustrated.

Unveiling Trichosporon austroamericanum sp. nov.: A Novel Emerging Opportunistic Basidiomycetous Yeast Species

During an epidemiological survey, a potential novel species within the basidiomycetous yeast genus Trichosporon was observed. The clinical strain was obtained from a urine sample taken from a Brazilian kidney transplant recipient. The strain was molecularly identified using the intergenic spacer (IGS1) ribosomal DNA locus and a subsequent phylogenetic analysis showed that multiple strains that were previously reported by other studies shared an identical IGS1-genotype most closely related to that of Trichosporon inkin. However, none of these studies provided an in-depth characterization of the involved strains to describe it as a new taxon. Here, we present the novel clinically relevant yeast for which we propose the name Trichosporon austroamericanum sp. nov. (holotype CBS H-24937). T. austroamericanum can be distinguished from other siblings in the genus Trichosporon using morphological, physiological, and phylogenetic characters.

Cultural, Morphological and Pathogenic Variability in the Colletotrichum capsici Isolates, Inciting Anthracnose and Fruit rot of Chilli (Capsicum annuum L.) in different Agro-Climatic Zones of Kerala, India

Aims: To study the cultural, morphological and pathogenic variability existing among the pathogen isolates of Colletotrichum capsici, inciting anthracnose and fruit rot of chilli in Kerala. Study Design: Completely randomized design (CRD). Place and Duration of Study: Department of Plant Pathology, College of Agriculture (Kerala Agricultural University), Vellayani, Thiruvananthapuram during 2018-2019. Methodology: A survey was conducted in the five agro-climatic zones (ACZs) of Kerala viz., Northern zone, Central zone, Special problem zone, High range zone and Southern zone to assess the incidence and severity of anthracnose disease. The various symptoms in the surveyed locations were also noted. Pathogen isolates were grown in PDA medium in the laboratory and colony characters (colour and mycelial growth rate of pathogen colonies) were observed. Also, the morphological characters viz., mycelial width, shape and size of conidia, acervular diameter, number and size of setae, appressorial size were recorded. Results: Maximum anthracnose incidence of 90 per cent and severity of 52.60 per cent were noticed at Regional Agricultural Research Station (RARS), Pilicode (Northern zone). Characteristic leaf spot, fruit rot and die-back symptoms were observed in the survey locations. Pathogen colonies showed different shades of white, off-white to grey turning brown or black with regular or irregular margins and concentric rings of black acervuli in the potato dextrose agar (PDA) medium. The diameter of growth of C. capsici isolates ranged from 7.20 to 8.60 cm at 7 days after incubation. All the C. capsici isolates initiated hyaline mycelium having a width of 1.73 - 2.36 µm and produced numerous sickle shaped conidia with a size range of 19.42 - 20.46 µm × 2.16 - 3.09 µm. Black coloured, circular or ellipsoidal acervuli (122.14 - 189.08 µm dia.) had 20 – 46 setae of length 74.13 to 107.30 µm. Also, brown or black appressoria of size 8.64 - 12.64 µm × 5.54 - 7.84 µm were formed in slide culture. Cc3 from College of Agriculture, Vellanikkara was obtained as the most virulent isolate producing a lesion size of 1.13 cm and PDI of 45.33 in the artificially inoculated chilli fruits (var. Vellayani Athulya) at 5 days after inoculation. Conclusion: All the nine C. capsici isolates exhibited variability in their cultural, morphological and pathogenic characteristics. Variability in phytopathogenic fungi helps in identifying novel and sustainable control methods to tackle the diseases incited by them. Understanding pathogen variability provides new insights for developing effective disease management methods. This will help in promoting sustainable agriculture and preventing severe crop losses.

Taxonomy and phylogeny of the family Suberitidae (Porifera: Demospongiae) in California

This study presents a comprehensive taxonomic revision of the family Suberitidae (Porifera: Demospongiae) for California, USA. We include the three species previously known from the region, document two additional species previously known from other regions, and formally describe four new species as Pseudosuberites latke sp. nov., Suberites californiana sp. nov., Suberites kumeyaay sp. nov., and Suberites agaricus sp. nov. Multi-locus DNA sequence data is presented for seven of the nine species, and was combined with all publicly available data to produce the most comprehensive global phylogeny for the family to date. By integrating morphological and genetic data, we show that morphological characters may be sufficient for regional species identification but are likely inadequate for global classification into genera that reflect the evolutionary history of the family. We therefore propose that DNA sequencing is a critical component to support future taxonomic revisions.