Search Results (253)

Two new species of free-living marine nematodes from mangrove wetlands of Beihai, Guangxi province in China, are described and illustrated. Trissonchulus sinensis sp. nov. is characterized by a head continuous with the body, an amphidial fovea pouch-shaped, pharynx expanding gradually but not forming a posterior bulb, spicules sclerotized, blade-shaped, slightly curved ventrally, proximal part enlarged with a prominent central septum, posterior part slender and handle-like; gubernaculum small, composed of two distally connected sheet-like structures with tooth-like ends, and lacking apophysis. Metachromadora sinica sp. nov. is characterized by a cuticle that is finely annulated, labial sensilla papilliform, cephalic setae four in number, amphideal fovea loop-shaped, exhibiting a double-contoured appearance, pharyngeal bulb well-developed, internal cuticular lumen tripartite, lateral epidermal ridges present, spicules slender with an enlarged capitulum, gubernaculum boat-shaped, precloacal supplements absent, tail conical with two setose protuberances, three pairs of subventral preanal setae, and a pair of papillae situated anterior to the anus. Nearly full-length SSU sequences and D2-D3 of LSU sequences are provided for the new species. Phylogenetic analysis of SSU provided support for the current classification status of the two new species. In the SSU phylogenetic tree, the family Ironidae was recovered as a separate monophyletic clade. However, the phylogenetic relationships within the family Desmodoridae were complicated, and the subfamilies Desmodorinae and Spiriniinae were polyphyletic. A comprehensive taxonomic approach combining morphological observations and molecular phylogeny construction would be particularly valuable in a more robust nematode taxonomy. Full article

Sporothrix schenckii is a pathogenic fungus with both clinical and environmental origins that was traditionally described as a single species but is increasingly recognized as being genetically diverse. In this study, we analyzed multiple isolates recovered from human sporotrichosis cases and environmental sources across Latin America (Mexico, Guatemala, Colombia). We conducted a polyphasic analysis of 16 isolates, integrating morphological data with multilocus sequence analysis (MLSA) targeting the internal transcribed spacer (ITS), calmodulin (CAL), β-tubulin (BT2), and translation elongation factor 1-α (TEF) gene regions. Phylogenetic relationships were resolved via maximum likelihood, and genetic structure was corroborated via four independent clustering methods: minimum spanning tree, principal component analysis, multidimensional scaling, and self-organizing maps. MLSA reidentified six isolates as S. globosa and confirmed the absence of S. brasiliensis in the cohort. The remaining S. schenckii s. str. isolates were resolved into three clades (A, B, and C). Notably, clade B (EH748, EH194, and EH257) formed a genetically divergent cluster with the highest nucleotide diversity (π = 0.03556) and was consistently segregated by all clustering algorithms. Clinical and environmental isolates were phylogenetically intermingled, supporting an active environmental reservoir for human infections. Phenotypic data, including colony size and conidial and yeast dimensions, varied but did not clearly distinguish between clinical and environmental origins. Our study provides compelling molecular evidence for a previously unrecognized, highly divergent clade within S. schenckii s. str., indicative of ongoing cryptic speciation. These findings refine the taxonomy of medically important Sporothrix species and reveal a distinct epidemiological profile for sporotrichosis in the studied regions, separate from the S. brasiliensis-driven epizootic. This highlights the critical role of molecular surveillance for accurate diagnosis, treatment, and public health strategies. Full article

Dendrobium is an orchid genus with high economic and ecological importance, but its taxonomy based on morphology remains controversial. Dendrobium linawianum, a critically endangered species with both ornamental and medicinal value, represents a key taxon within this genus. However, its phylogenetic relationship has long been unplaced due to similar morphological traits. Despite its conservation and taxonomic importance, its complete chloroplast genome has not been previously characterized. Here, we newly sequenced and assembled the complete chloroplast genome of D. linawianum. The 150,497 bp genome exhibits a typical quadripartite structure, encoding 119 genes. A total of 161 simple sequence repeats (SSRs) were identified, predominantly mononucleotide and dinucleotide motifs. Condon usage analysis revealed leucine as the most abundant amino acid. Phylogenetic analysis based on complete chloroplast genome sequences strongly supported the close relationship of D. linawianum with D. hercoglossum, D. thyrsiflorum, and D. moniliforme, resolving its taxonomic position within the genus. The complete chloroplast genomes successfully resolved the phylogenetic relationships among 35 Dendrobium species, demonstrating their efficacy as powerful molecular markers for resolving taxonomic ambiguities within this morphologically complex genus. Our findings provide a genomic foundation for precise species identification and molecular breeding of D. linawianum, and enhance understanding of phylogenetic relationships in this taxonomically challenging group. Full article

This study reports the discovery of four novel Pinnularia species—P. latocentra sp. nov., P. rhombocentra sp. nov., P. seouloflexuosa sp. nov., and P. paristriata sp. nov.—from urban freshwater streams in South Korea. Species delimitation was achieved using a polyphasic approach that integrated light and scanning electron microscopy, ecological profiling, and molecular evidence from SSU rRNA and rbcL sequences. Each taxon was confirmed as morphologically and genetically distinct from its closest congeners. Our findings broaden the recognized diversity of Pinnularia in East Asia and demonstrate that urban streams, often regarded as degraded habitats, can harbor hidden diatom diversity and ecological complexity. By clarifying diagnostic traits, validating type material in a recognized repository, and aligning molecular and morphological evidence, this study contributes to a more robust taxonomy of Pinnularia. These results also highlight the importance of polyphasic taxonomy and the strategic inclusion of urban habitats in diatomological surveys and biodiversity assessments. Full article

China is a global hotspot for amphibian biodiversity, yet under-explored montane regions harbor undiscovered cryptic species. Using integrative taxonomy, we describe a new salamandrid species, Pachytriton cheni sp. nov., from Qingliangfeng Nature Reserve, Anhui. Phylogenetic analyses of mitochondrial (ND2, cytb) and nuclear (RAG1, POMC) genes strongly support it as a monophyletic sister lineage to P. granulosus, with significant mitochondrial p-distances (4.39–10.22%) and unique nuclear haplotypes. Bayes factor species delimitation under the multispecies coalescent model (MSC) decisively rejects conspecificity with P. granulosus (2lnBF = 24.52). Morphologically, it is diagnosed by its small size; oval, narrow head (length > width); nearly black dorsum lacking bright orange spots; smooth skin; occipital V-shaped ridge; orange-red abdomen with brown markings; prominent neck folds; and minimal digit gap when limbs are adpressed. This discovery increases Pachytriton species to ten, highlights high-elevation montane ecosystems as key biodiversity refuges in East China, and underscores the need for further surveys to clarify the genus’s phylogeny. Full article

Heliaster has long been considered to comprise seven nominal species of starfish distributed across the Eastern Pacific, from Baja California (Mexico) southward to central Chile. Along the southeastern Pacific coast, three taxa have been traditionally recognized: H. helianthus (Paita, northern Peru, to Concepción, central-southern Chile), H. polybrachius (Mexico to Perú), and H. canopus (Juan Fernández Archipelago and Desventuradas Islands). However, extensive morphological overlap among these forms has cast doubt on the validity of H. canopus, with some authors treating it as a synonym for H. helianthus. To clarify this ambiguity, we applied an integrative framework combining detailed morphometrics, phylogenetic inference from mitochondrial (COI) and nuclear (H3) markers, and two species delimitation approaches (bPTP and ASAP). Our sampling spanned Peru, continental Chile, and the oceanic islands of Juan Fernández and Desventuradas. Variation in ray number and relative arm length among H. helianthus, H. canopus, and H. polybrachius proved allometric, scaling strongly with body diameter rather than indicating discrete species boundaries. Molecular data show >95% sequence similarity across all nominal taxa and recover a single, well-supported clade; bPTP and ASAP likewise support one Heliaster lineage throughout the southeastern Pacific, corresponding to H. helianthus. Accordingly, we redescribe H. helianthus, designate a neotype from Quintay, Chile, and formally synonymize H. canopus and H. polybrachius under H. helianthus. Our results indicate that a single species spans the Eastern Pacific from Ecuador and Peru to central-southern Chile, including offshore islands, underscoring the value of integrative taxonomy for robust delimitation and accurate biodiversity assessments in marine invertebrates. Full article

The green macroalgae Ulva Linnaeus, 1753, also known as sea lettuce, is one of the most ecologically and economically significant algal genera. Its representatives occur in marine, brackish, and freshwater environments worldwide and show high adaptability, rapid growth, and marked biochemical diversity. These traits support their ecological roles in nutrient cycling, primary productivity, and habitat provision, and they also explain their growing relevance to the blue bioeconomy. This review summarizes current knowledge of Ulva biodiversity, taxonomy, and physiology, and evaluates applications in food, feed, bioremediation, biofuel, pharmaceuticals, and biomaterials. Particular attention is given to molecular approaches that resolve taxonomic difficulties and to biochemical profiles that determine nutritional value and industrial potential. This review also considers risks and limitations. Ulva species can act as hyperaccumulators of heavy metals, microplastics, and organic pollutants, which creates safety concerns for food and feed uses and highlights the necessity of strict monitoring and quality control. Technical and economic barriers restrict large-scale use in energy and material production. By presenting both opportunities and constraints, this review stresses the dual role of Ulva as a promising bioresource and a potential ecological risk. Future research must integrate molecular genetics, physiology, and applied studies to support sustainable utilization and ensure safe contributions of Ulva to biodiversity assessment, environmental management, and bioeconomic development. Full article

The genus Pasiphaea Savigny, 1816, comprises a diverse assemblage of meso- to bathypelagic shrimps, currently including 69 valid species. Taxonomic investigations have long been hampered by numerous synonymies and by species known only from their original, overly brief descriptions. Here, we address these deficiencies by examining Pasiphaea specimens collected in the Western and Central Pacific during multiple research cruises using mid-water trawls. Integrating traditional morphological characters (carapace carination, pleonal relief, telson end morphology, and pereopodal dentition) with a novel morphometric framework, we standardized terminology and defined a suite of quantitative measurements across the carapace, pleon, telson, and chelae. In order to corroborate species boundaries, we sequenced three mitochondrial gene markers (COI, 16S rDNA, and 12S rDNA) and calculated genetic distances under the Kimura two-parameter model. This combined approach extended or confirmed the geographic ranges of five described taxa, facilitated the formal description of eight new species, and demonstrated the synonymy of P. gracilis Hayashi, 1999, and P. fragilis Hayashi, 1999. Phylogenetic reconstructions further highlighted cases of pseudocryptic speciation in neighboring bathyal habitats. Our results expose substantial lacunae in the Southwest Pacific Pasiphaea fauna and substantiate the necessity for a comprehensive, genus-level revision. This study thereby contributes to both refining species diagnoses and advancing our understanding of deep-sea crustacean biodiversity. Full article

Our current knowledge of the cyanobacterial diversity in Egypt is still underestimated During our routine study on Egyptian cyanobacteria, two interesting and morphologically cryptic strains were isolated from streams of Bahr Yussef and Qarun Lake, one of the oldest lakes in the world, located at the Faiyum depression, Egypt. We applied the polyphasic approaches, combining the state-of-the-art morphotaxonomy, 16S rRNA gene phylogenies, and ecological preferences to precisely unravel the taxonomic positions of these two cyanobacterial strains. Based on a combination of their morphotaxonomic traits and 16S rRNA phylogenetic assessment, we identified them as Alkalinema pantanalense (Leptolyngbyaceae, Leptolyngbyales) and Roholtiella edaphica (Nostocaceae, Nostocales). Both species are considered new cyanobacterial records for Egypt and the African continent based on the available literature. From an ecological standpoint, both species are eutraphentic, where they could tolerate relatively elevated concentrations of NO₃⁻, NH₄⁺ (in particular for R. edaphica), and silicates, reflecting eutrophication signs in the ecosystems they colonize. This study adds to the limited molecular information available on the Egyptian cyanobacteria, and also highlights the need for re-investigation of Egyptian cyanobacteria, using polyphasic approaches, to better understand their taxonomy and ecology. Full article

Species diversity within the green pit vipers of the genus Trimeresurus is likely underestimated. In this study, we describe a new species of Trimeresurus from the Xizang Autonomous Region, China, based on both morphological and molecular evidence. The new species, Trimeresurus pretiosus sp. nov., is assigned to the subgenus Viridovipera Malhotra Thorpe. It is distinguished from its congeners by the following combination of morphological characters: (1) first supralabial completely separated from nasal scale; (2) hemipenis short and spinose, reaching the 12th subcaudal when fully everted; (3) small adult size, with a maximum known snout-vent length of 516 mm in males and 512 mm in females; (4) dorsal scales in 19–19–15 rows, weakly keeled except for the outermost rows; (5) 140–143 ventral scales; (6) 56–58 subcaudal scales in males and 54 in females, partially arranged in a single row; (7) iris reddish-brown in males, orange-yellow in females; (8) body uniformly bright grass-green; postocular streak absent or faint white in males, absent in females; (9) ventrolateral stripe consisting of red above and white below and wide in males, only white and narrow in females; (10) ventral surfaces greenish-yellow; (11) tail distinctly reddish-brown dorsally, with the colouration extending from tail base to tip. Molecular analyses based on the mitochondrial 16S, cyt b, and ND4 gene fragments indicate that the new species is genetically divergent from all congeners, with uncorrected p-distances ranging from 5.8% to 12.5% in the cyt b gene and from 6.7% to 11.0% in the ND4 gene. The new species is currently known only from the southern slopes of the central Himalayas in Yadong County, and it represents the second known Viridovipera species from the southern Himalayas. With this discovery, the total number of snake species known from the Xizang Autonomous Region increases to 67, underscoring the importance of continued herpetofaunal surveys in this biogeographically complex region. Full article

In a survey of Bajiaozhai National Forest Park (Guilin, China), several specimens of an Euseius sp. were collected. These specimens were very similar to Euseius nicholsi and Euseius oolong, based on morphological observations. However, some morphological characters, such as the body size, number of solenostomes on the dorsal plate, calyx shape of the spermatheca, the shape and number of metapodal platelet, teeth number on the fixed digit, length of setae j3, and macroseta Seg IV, Sti IV, and St IV were different between these specimens and E. nicholsi and E. oolong. To ascertain whether these morphological differences were interspecific or intraspecific variations, molecular analyses were conducted using mitochondrial DNA COI, 12S rRNA, and nuclear ITS markers. Based on the three molecular markers, minimal genetic distances were observed (COI 0–4%, 12S rRNA 0–2%, and ITS 0%) among the putative Euseius sp., E. nicholsi (collected from Bauhinia purpurea in IZGAS and from Eurya macartneyi and Ficus hispida in Shaoguan City), and E. oolong (collected from B. purpurea in IZGAS). Amblyseius swirskii was used as the outgroup. Using the maximum likelihood method, the phylogenetic tree showed that these specimens of Euseius sp., E. nicholsi, and E. oolong clustered in a single clade. Therefore, we propose that this putative Euseius sp. is E. nicholsi, and E. oolong is a junior synonym of E. nicholsi. This study demonstrates the importance of integrative taxonomy for the proper identification of phytoseiid mites. Full article

The genus Sclerodermus Latreille (Hymenoptera: Bethylidae) comprises over 80 species of ectoparasitoids of insect pests in forests, agricultural environments, and stored products with a cosmopolitan distribution. Despite its growing significance in biological control, behavioral ecology, and public health, the taxonomy of the genus remains poorly resolved. This is largely due to morphological reduction and simplification among species, outdated or incomplete original descriptions, and limited access to type material. A particularly problematic case is Sclerodermus cereicollis Kieffer, originally described from two geographically disjunct populations: Giglio Island (Italy, Palaearctic) and Annobón Island (Equatorial Guinea, Afrotropical). The syntype series includes morphologically divergent specimens, casting doubt on their conspecificity. In this study, we redescribe S. cereicollis based on both the original syntypes and newly collected material from Italy. A lectotype is designated to stabilize the nomenclature, and we provide the first molecular data for the species to assess genetic cohesion among populations. Comparative morphological and molecular analyses reveal that the Afrotropical syntypes represent a distinct, previously undescribed species. Accordingly, we describe Sclerodermus annobonensis Masini, Colombo & Azevedo sp. nov., designating a holotype. This study refines species boundaries within Sclerodermus and highlights the value of integrative taxonomy, combining historical and contemporary data, in resolving persistent systematic ambiguities in morphologically conservative taxa. Full article

The genus Sargassum is taxonomically complex and poorly studied in the Eastern Tropical Pacific. We analyzed specimens collected along the Pacific coast of Central America and compared them with historical records and herbarium material to clarify species identities. Using detailed morphological analyses with molecular phylogenetic reconstruction based on concatenated ITS2 (Internal Transcribed Spacer 2) and COX3 (Cytochrome Oxidase Subunit 3) sequences, we identify two distinct morphotypes corresponding to two well-supported clades. One clade matches the morphology and molecular profile of Sargassum liebmannii. We provide the most comprehensive description of this species to date, including the first published ITS2 and COX3 sequences. Since Taylor’s 1945 work on the tropical Pacific of the Americas, S. liebmannii has been widely reported and considered the predominant species. It forms a genetic clade with other species from the Gulf of California; therefore, we propose a new section, Herporhizum/Sinicola. The second clade represents a previously unrecognized taxon from Central America, which we describe as a new species: Sargassum lacrucense, within the subgenus Sargassum, section Sargassum. Contrary to previous reports, Sargassum brandegeei—now recognized as Sargassum herporhizum—was not found in the region. This study underscores the importance of integrating morphological and molecular data to resolve Sargassum taxonomy in Central America. Full article

The genus Raiamas currently comprises 18 valid species, only 2 of which occur in Asia; the remaining 16 are endemic to Africa. Raiamas harmandi was originally described by Sauvage in 1880 as Bola harmandi, which is distributed in the Great Lakes, Cambodia, the Mekong River Basin. It was considered a synonym of R. guttatus by later researchers. In this study, we examined 49 Raiamas individuals from the Mekong, Irrawaddy, and Salween river basins, recording both meristic counts and morphometric measurements. Based on the morphological evidence, we revised the taxonomy of Raiamas in the Mekong River Basin, confirming R. harmandi as a valid species and providing a comprehensive redescription. Raiamas harmandi can be distinguished from R. guttatus mainly by having more predorsal scales (25–28 vs. 21–23) and a different color pattern on the lateral body. Utilizing a total of 44 aligned COI and Cyt b sequences—including eight newly sequenced individuals of Raiamas from three river basins—we reconstructed its phylogenetic relationships. The analysis strongly supported four R. harmandi individuals from the Mekong River Basin forming a distinct clade, which was the sister to the clade comprising five R. guttatus individuals from the Irrawaddy and Salween river basins. Genetic distances between R. harmandi and R. guttatus ranged from 14.0 to 14.9% for COI and 16.1 to 17.0% for Cyt b. Distributionally, R. harmandi occurs throughout the Mekong River Basin, as evidenced by combined voucher specimens and molecular sequence data. Full article

The genus Discobola Osten Sacken, 1865 from China is taxonomically reviewed using an integrative approach that combines detailed morphological examination and molecular analysis. Discobola parvispinula (Alexander, 1947), a species widely distributed across the Palaearctic region, is newly recorded from China. Updated distributional data are presented for species known from China: D. annulata (Linnaeus, 1758), D. armorica (Alexander, 1942), D. margarita Alexander, 1924, and D. taivanella (Alexander, 1930). Detailed redescriptions and illustrations, including intraspecific morphological variation, are provided for these species. An identification key to Chinese Discobola species is also presented. Geographical analysis reveals a higher species richness in southern China and the Qinghai–Tibet region, with a progressive decline toward northern and northwestern China. The first DNA barcode reference library for Chinese Discobola is established, comprising 15 mt COI sequences from five species. These sequences, analyzed alongside an additional 101 mt COI sequences from Discobola species in other countries, show that intraspecific divergence within the genus remains below 7.4%, while interspecific divergence ranges from 7.6% to 17.7%. These findings provide important insights into the taxonomy, species delimitation, and biogeography of Discobola in China, contributing to a more comprehensive understanding of Discobola diversity across the region. Full article