Search Results (554)

A previous analysis of diversity within the Monomorium nigrius Forel group, formally recognized as a single species, concluded that >200 species may occur in the Australian monsoonal tropics (AMT). Here, we test this conclusion by incorporating CO1 data from an additional 223 M. nigrius group specimens collected from the monsoonal tropics of the Northern Territory (NT). By integrating morphological variation, CO1 structure and divergence, and geographic distribution, we recognized 85 species from monsoonal NT. PTP and bPTP analyses, which consider CO1 structure and divergence alone, recognized 107 and 136 species, respectively. Using a distance-based clustering approach, the number of OTUs defined by a CO1 divergence threshold of 1–6% ranged from 163 to 37. Given that sampling remains highly patchy, many more than the 85 species recognized here are likely to occur in monsoonal NT. Only four of the 85 species are known from elsewhere in the AMT. Given such high rates of species turnover, our findings support the conclusion that the total number of AMT species in the M. nigrius group likely exceeds 200. Remarkable levels of unrecognized hyperdiversity occur in many ant species groups in the AMT, challenging the traditional understanding that peak ant diversity occurs in tropical rainforest biomes. Full article

The delimitation of cryptic species represents one of the main challenges, particularly in groups with low external morphological differentiation. In this context, scanning electron microscopy (SEM) enables the detection of diagnostic characters at the microscale. This study evaluates the potential of ocular morphology for interspecific discrimination within a group of species of the genus Temnothorax. A total of 246 workers from 52 nests, 13 populations, and 8 species from the Iberian Peninsula and North Africa were analyzed. Morphometric variables related to compound eyes were quantified from SEM images (ommatidia number, interommatidial setae, eye diameter). Data were analyzed using ANOVA, effect size estimation (η²), Linear Discriminant Analysis (LDA), and Random Forest models. All variables showed significant differences among species (p < 0.001), with varying discriminative power. Variables related to ommatidial organization exhibited the highest classification performance, achieving high rates of correct species assignment in multivariate analyses. The use of nest-level means values substantially improved classification accuracy. These results demonstrate that ocular morphology analyzed through SEM represents a promising complementary tool for species discrimination in Temnothorax, complementing traditional and molecular approaches. Full article

Stipitate stereoid fungi are saprotrophic basidiomycetes characterized by a leathery basidiome, a central-to-lateral stipe and infundibuliform pilei. Although numerous species of stipitate stereoid fungi have been recorded worldwide, understanding of their phylogenetic relationships remains extremely limited, and research on this group of fungi in China is insufficient. In this study, specimens of the three stipitate stereoid genera, namely Podoscypha s. l., Cymatoderma s. l. and Stereopsis s. l., from southern China were investigated. Phylogenetic analyses of the internal transcribed spacer (ITS) regions and the large subunit of the nuclear ribosomal RNA gene (LSU) using maximum likelihood (ML) and Bayesian inference (BI) methods revealed that all three genera are polyphyletic. Consequently, Podoscypha s. s. and Cymatoderma s. s. were delimited, and Cladoderris—previously synonymized with Cymatoderma—was resurrected. Cladoderris is characterized by an imbricate basidiome, tomentose pilei and basidiospores typically shorter than 4 μm in length. Three new species, Podoscypha casiae, Stereopsis buccinata and Cladoderris perennis, were described and illustrated. The morphological distinctions and affinities between the new species and closely related taxa were discussed, the thresholds for the intraspecific and interspecific demarcation within the three genera in this study were provided, and identification keys for the species of each genus were presented. Full article

Accurate species delimitation is fundamental yet challenging, particularly in recently diverged, phenotypically conservative taxa such as bats. The “Rhinolophus macrotis group” represents one of the most taxonomically contentious groups among horseshoe bats. During field surveys in Southwest China, we discovered an unidentified Rhinolophus sp. occurring sympatrically with R. osgoodi and R. episcopus, sharing broad morphological affinities with recognized species of the “R. macrotis group.” To explore its taxonomic status, we employed an integrative approach combining morphological, acoustic, and multi-locus genetic (mitogenomic and nuclear) data. Phenotypically, Rhinolophus sp. closely resembles R. osgoodi but can be distinguished by its divergent echolocation resting frequency. Genetically, while mitochondrial data deeply nested Rhinolophus sp. within R. osgoodi with a shallow divergence time, phylogenies based on two nuclear introns positioned it closer to two other species, R. episcopus and R. siamensis. Species delimitation based on these genetic markers revealed a pattern of mitochondrial subdivision contrasted by overly conservative nuclear signals. Such mito-nuclear discordance suggests a complex evolutionary history that complicates taxonomic assignments. Given that only three specimens of Rhinolophus sp. were available, which precludes a robust assessment of intraspecific variation, we provisionally designate it as a candidate lineage within the “R. macrotis group,” warranting future validation with additional comprehensive evidence. This study highlights the indispensable utility of integrative taxonomy in uncovering hidden diversity and provides insights into chiropteran evolutionary history. Full article

Describing novel microbial species opens access to uncharted biosynthetic gene clusters and their associated secondary metabolites, offering fresh opportunities in the search for new antibiotics urgently needed to combat multidrug resistance. In this study, we describe a new species of Streptomyces, S. marxii sp. nov. (type strain VKM Ac-3100), an actinobacterium isolated from soil in the Yaroslavl Region of Russia. Using a polyphasic taxonomic approach that included whole-genome sequencing (WGS), we found that the strain’s average nucleotide identity (ANI) and digital DNA–DNA hybridisation (dDDH) values relative to its closest relative, S. maoxianensis, were 92.53% and 47.9%, respectively. Both values fell significantly below the species delimitation thresholds. Functional screening using the pDualrep2 dual fluorescent reporter system identified a unique SOS-silent antimicrobial profile characterised by growth inhibition without induction of the SOS response or translation stress. High-resolution mass spectrometry (HRMS) and genomic mining revealed that this activity is linked to the production of kinanthraquinone B ([M+H]⁺ m/z 275.0550), a rare polycyclic aromatic polyketide. Genomic analysis identified a specialised type II polyketide synthase (T2PKS) biosynthetic gene cluster (BGC) with evidence of acquisition via horizontal gene transfer (HGT). Our findings characterise S. marxii as a promising natural producer of rare catalytic inhibitors of DNA topoisomerases II and IV, offering a scaffold for the development of antibiotics with potentially lower genotoxicity. Full article

Rivulid killifishes are among the most threatened components of freshwater biodiversity in the Brazilian Atlantic Forest, yet their biogeographic patterns remain poorly documented. This study provides the first comprehensive biogeographic assessment for rivulids across the Southeastern and Eastern Atlantic basins of Brazil. We compiled distribution records for 54 species, analyzing patterns of endemism, similarity between hydrographic regions, and sampling coverage. Our results reveal patterns of hyper-endemism, with 31 species (57.4%) restricted to single basins and a highly aggregated distribution. Faunal similarity between regions was negligible, indicating strong historical isolation, with only 3.7% of species shared between the Eastern and Southeastern Atlantic basins. Seventeen bioregions were delimited across the study area, with minimal faunal overlap. We identified that 50.0% of basins lack any rivulid records, despite the region having been extensively sampled for more than 150 years (including since the Thayer Expedition of 1865–1866). This study area contains the highest concentration of research institutions in Brazil, suggesting that the absence of records reflects genuine absence rather than a sampling artefact. Based on endemism values, we highlight 16 priority basins for urgent conservation management. These findings reveal that small coastal basins harbor a disproportionately high, imperiled, yet overlooked diversity. We argue that effective conservation of this unique evolutionary heritage requires targeted research in unsampled areas, basin-scale management, and expanded protected area mosaics to incorporate these high-endemism micro-basins. Our results provide the biogeographic foundation for evidence-based strategies to prevent the extinction of these fishes. Full article

Two new species of the flesh fly subgenus Sarcophaga Meigen, 1826 (Diptera: Sarcophagidae), Sarcophaga (S.) karai sp. nov. and Sarcophaga (S.) hayati sp. nov., are described from Türkiye. For each new taxon, detailed morphological descriptions, differential diagnoses, and high-resolution illustrations of the male terminalia are provided. The genital structures of the newly recognized taxa were further examined using scanning electron microscopy (SEM), allowing detailed characterization of surface morphology and fine ultrastructural features not discernible with conventional optical methods. The diagnostic value of key morphological structures of the male terminalia is discussed in the context of species delimitation within the subgenus. Each new species is compared with those most similar in terminalia morphology, and an updated identification key to the males of Turkish representatives of the subgenus is provided to facilitate future faunistic studies in the region. These findings contribute to a more comprehensive understanding of sarcophagid diversity across the Anatolian Peninsula and highlight the substantial species richness that remains to be documented within this group. Full article

Termite-associated Ophiocordyceps species remain understudied despite the high diversity of the genus. Here we describe Ophiocordyceps minuta (holotype CXAC 0026) from termites (Termitidae, Macrotermitinae) collected in Yunnan, China. Phylogenetic analyses based on nrLSU (nuclear large subunit ribosomal RNA), tef1-α (translation elongation factor 1-alpha), and rpb2 (RNA polymerase II second largest subunit) sequences resolve this fungus as a distinct lineage. Notably, deep genetic divergence (65 bp in tef1-α) between the two ex-type strains of the allied O. fusiformis (BCC 93025 and BCC 93026) reveals cryptic diversity within that nominal species. Beyond the new species, a morphological assessment of termite-associated Ophiocordyceps indicates that perithecial immersion status, ascospore morphology, and conidial features are the most taxonomically valuable characters for this ecological group. These findings expand the known diversity in southwest China and underscore the importance of integrating phylogenetic data with key morphological traits for species delimitation in under-explored habitats. Full article

Allium aralii Balos, Köse & Sonay sp. nov. (Amaryllidaceae, sect. Codonoprasum) is described as a new species from southeastern Anatolia, Türkiye. The species is morphologically distinguished from its closest relatives—A. euphraticum, A. turcicum subsp. turcicum, A. turcicum subsp. fusciflorum, and A. yilandaghense—by a unique combination of characters: blackish outer bulb tunics, semi-cylindrical solid leaves exceeding the inflorescence, an extremely long persistent two-valved spathe (4.5–28.0 cm), a lax hemispherical inflorescence (3–4 cm diam., 10–70 flowers), a goblet-shaped perigon with dentate inner tepals, exserted bicolored stamens (white at base and apex, purple in the middle), a reticulate-foveate ovary, and verrucate seed ornamentation with undulate anticlinal walls. Seed micromorphology examined by scanning electron microscopy (SEM) further supports species delimitation. Molecular phylogenetic analyses based on nuclear ITS and chloroplast matK sequences place A. aralii within a well-supported clade containing A. turcicum and allied species, corresponding to the eastern Mediterranean lineage of sect. Codonoprasum. ITS genetic distances between A. aralii and its morphologically closest relatives range 0.0632, falling within the typical interspecific range for Allium. The species is known from a single locality in Bozova district (Şanlıurfa) with fewer than 100 mature individuals and is assessed as Critically Endangered (CR) according to IUCN criteria. This discovery highlights southeastern Anatolia as an underexplored center of Allium diversification and underscores the importance of integrative taxonomy for species delimitation within this taxonomically complex group. Full article

The taxonomy and distribution of Kaempferia subgen. Protanthium (Zingiberaceae) in Myanmar remain incompletely documented despite the botanical significance of the region. This study aims to clarify the diversity and taxonomic status of species belonging to this subgenus in Myanmar through field investigations and herbarium studies. Detailed morphological examinations of newly collected and previously documented specimens were conducted to evaluate diagnostic characters and species delimitation. As a result, Kaempferia kayinensis is described in this paper as a new species from Kayin State, southeastern Myanmar, and K. simaoensis Y.Y.Qian as a new country record. In addition, the taxonomic status of K. parishii Hook.f. is reassessed and reinstated based on morphological evidence, distinguishing it from K. ovalifolia Roxb. These findings confirm the presence of four species of Kaempferia subgen. Protanthium in Myanmar (K. kayinensis, K. parishii, K. rotunda, and K. simaoensis) and increase the number of known Kaempferia species in the country to twelve. The results highlight the importance of continued floristic and taxonomic studies to better document the diversity of Kaempferia in Myanmar. Full article

Loricaria, the type genus of the armored catfish family Loricariidae, is a species-depauperate lineage in the subfamily Loricariinae, with only 18 valid species formally recognized to date. However, the extremely high morphological homogeneity across congeners of this genus has long posed great obstacles to accurate taxonomic delimitation when relying solely on phenotypic traits. In this study, we newly sequenced and fully annotated the complete mitochondrial genomes (mitogenomes) of L. parnahybae and L. simillima. The two assembled mitogenomes are 16,581 bp and 16,371 bp in length respectively, both carrying the conserved vertebrate mitochondrial gene set consisting of 37 functional units (22 transfer RNA genes, 13 protein-coding genes (PCGs), 2 ribosomal RNA genes) and 1 non-coding control region. Among Protein Control Genes, only the Cox1 gene uses GTG as the start codon, whereas the remaining 12 PCGs initiate with ATG. The observed stop codons include TAA, as well as the incomplete stop codons TA and T. We reconstructed phylogenetic trees using both maximum likelihood and Bayesian inference methods, based on a dataset covering mitogenome sequences of 22 Loricariidae species and 2 outgroup taxa. Phylogenetic analyses consistently supported the monophyly of Loricariinae, Hypostominae, and Hypoptopomatinae. These results clarify the evolutionary position of L. simillima and L. parnahybae within Loricariidae and will contribute to elucidating the complex phylogenetic relationships among Loricariidae species. Full article

Gibellula (Cordycipitaceae, Hypocreales) represents a group of highly specialized obligate fungal pathogens restricted to spider hosts. Species delimitation was conducted using morphological characteristics in combination with multilocus phylogenetic analyses (nrSSU, ITS, nrLSU, tef1-α, rpb1, rpb2), and we recognized nine spider-associated Gibellula species from specimens collected in the Lancang–Mekong biodiversity hotspot (China, Laos, Thailand, and Vietnam). Among them, four are described as new to science: Gibellula longiconidiophora sp. nov., G. mekongensis sp. nov., G. ovorum sp. nov., and G. pseudopilosa sp. nov. The other five species represent new national distributional records: G. yunnanensis (new to Laos), G. pseudopigmentosa (new to Thailand), G. trimorpha (new to Vietnam), G. penicillioides (new to Laos), and G. scorpioides (new to China and Laos). Phylogenetic analyses resolved these taxa into well-supported lineages. Notably, G. ovorum is a rare example of a Gibellula species parasitizing spider egg sacs rather than adult spiders, revealing an unusual substrate shift. Morphological distinctions among the new species include differences in conidiophore length, synnematal development, conidial size, and sporulation patterns. Detailed descriptions, illustrations, and taxonomic comparisons are provided. This study significantly expands the known diversity and geographic distribution of Gibellula in the Lancang–Mekong region and underscores the importance of integrative taxonomy for uncovering hidden diversity in spider-pathogenic fungi. Full article

Lepiota sect. Stenosporae is characterized by a trichodermal or cutis-like pileus covering and spurred basidiospores. Although macroscopic similarities among its members complicate field identification, species can be delimited by combining multi-locus (ITS, nrLSU, rpb2, and tef1-α) phylogenetic analyses with distinct micro-morphological features. Using this integrative approach, we investigated specimens of sect. Stenosporae collected from Northeast China. A total of 12 species were successfully delimited, including six species new to science (Lepiota dolichospora, L. hongshiensis, L. jilinensis, L. microstenospora, L. sinocastanea, and L. sirupa) and one new record for China (L. grangei). Comprehensive morphological descriptions and line-drawing illustrations of microscopic features are provided for all recognized taxa. These findings expand the known species diversity of Lepiota in China and contribute morphological and molecular data for further systematic studies of this fungal group. Full article

Environmental DNA (eDNA) metabarcoding has emerged as a powerful tool for biodiversity monitoring, yet its accuracy is fundamentally constrained by the completeness and taxonomic reliability of reference sequence databases. For the Three Gorges Reservoir (TGR), no integrated multi-marker eDNA reference library exists, hampering standardized fish conservation monitoring under the Yangtze River Ten-Year Fishing Ban. Here, we constructed a comprehensive, multi-marker eDNA reference database for the fish fauna of the TGR, encompassing mitochondrial 12S rRNA, 16S rRNA, and cytochrome c oxidase subunit I (COI) gene sequences from 173 specimens (120 species) collected between 2021 and 2024. After integrating publicly available sequences, the final database comprised 161 species. Then, we quantitatively compared species annotation performance between this local database and public repositories. Results showed that while public databases achieved higher nominal species coverage (94.67%), they exhibited critical deficiencies in annotation accuracy, correctly annotating only 77.97% (12S rRNA), 75.00% (16S rRNA), and 38.14% (COI) of sequences from shared species under controlled conditions. In contrast, the local database exhibited 92.37%, 93.10% and 100% annotation accuracy for the respective markers. Optimal interspecific Kimura 2-parameter (K2P) thresholds for species delimitation were 0.00448 (12S rRNA), 0.00531 (16S rRNA), and 0.00734 (COI). In addition, 15, 0, and 4 species pairs exhibited zero interspecific distance for 12S rRNA, 16S rRNA, and COI, respectively. These limitations reinforce the need for cautious interpretation of eDNA metabarcoding results and the integration of multiple markers or complementary nuclear loci. This study provides preliminary evidence that regionally curated, multi-marker reference libraries could improve taxonomic assignment reliability in eDNA metabarcoding compared to uncurated public repositories, providing a foundational resource for biodiversity conservation. Full article

A microsporidian species, Glugea sp., was identified infecting the visceral cavity of commercial sardines (Sardina pilchardus) from an Atlantic fishery. Macroscopic examination revealed a white, friable mass that readily disintegrates, releasing spherical to ovoid microsporidian spores. Ultrastructural analysis shows an isofilar polar tube with 10–15 coils arranged in one to three rows. The study combined macrophotography, light microscopy, histological staining, transmission electron microscopy (TEM), and molecular analyses. Morphologically, Glugea sp. shares some features with Glugea vincentiae; however, molecular data do not support a close phylogenetic relationship between these two species. Phylogenetic analysis based on 18S rRNA sequences places the organism within a clade comprising G. plecoglossi, G. thunni, G. atherinae, G. gasterostei, G. hertwigi and G. anomala. Despite the high sequence similarity observed within this group, morphological and ultrastructural characteristics allowed differentiation of the present species, highlighting the limitations of relying solely on conserved molecular markers for species delimitation. A comprehensive morphological and molecular description of Glugea sp. is provided. Given the ecological and economic relevance of microsporidia, as well as their recognized role in animal and human disease, this new host–parasite association may have implications for fisheries and food safety, particularly considering the widespread consumption of sardines. Full article