Search Results (361)

The rhabdocoel family Trigonostomidae has been the subject of recent phylogenetic revisions. However, due to the limited number of sequenced taxa, questions regarding intrafamilial and intrageneric relationships remain unresolved. To address these gaps, we collected trigonostomids from the North Sea, the Mediterranean, and the Atlantic Ocean, and examined them using an integrative approach. Nineteen specimens, representing ten species, were sequenced for phylogenetic analyses. Eight species were sequenced for the first time, including the first molecular data for Lutheriella. All genera were recovered as monophyletic; however, Ceratopera falcata (type species of Messoplana) and a new closely related species were found to cluster with species of Beklemischeviella, while the remaining species of Ceratopera formed a distinct clade. Based on these findings, we propose the resurrection of Messoplana, which had previously been synonymised with Ceratopera. Notably, genetic divergence and differences in the bursal mouthpiece between specimens of M. falcata suggest the possible presence of cryptic diversity or geographical isolation within this taxon. The inclusion of Trigonostomum breitfussi provided molecular support for its morphologically defined group. Furthermore, L. diplostyla was found to be closely related to species of Ptychopera. In addition to phylogenetic analyses, we describe four new species: Ceratopera bransoni sp. nov., Messoplana judithae sp. nov., Parapharyngiella scotti sp. nov., and Ptychopera woodyi sp. nov. The discussion of the new species of Parapharyngiella and Ptychopera motivated the reclassification of Pt. scutulifera as Pa. scutulifera comb. nov. We record for the first time eight species from Florida, seven from the Indian River Lagoon, and two from the Florida Keys National Marine Sanctuary, in the USA. This study refines the phylogenetic framework and internal classification of Trigonostomidae by providing new molecular evidence for previously unsampled taxa and by re-evaluating generic boundaries within the family. Full article

Xinjiang, northwestern China, encompasses sharply contrasting desert–wetland and montane forest ecosystems, providing a natural setting to study species limits and habitat-associated morphological variation in Agaricus subgen. Pseudochitonia. We examined 303 specimens collected from 2021 to 2025 and generated 905 sequences across three loci (ITS, LSU, tef1). Species delimitation followed an integrative framework incorporating morphology, multilocus phylogeny, pairwise genetic distances, chemical reactions, and habitat data. We recognized ten species from Xinjiang. Among them, Agaricus acanthosquamosus is described as a new species in sect. Bohusia. It is recovered as a sister to A. bohusii and is distinguished by conspicuous squarrose spinose pileus scales, subglobose to broadly ellipsoid basidiospores, a solitary to scattered fruiting habit, and reddening context. We also document newly observed morphological variation in several previously described species. These include irregularly clavate cheilocystidia in A. desjardinii, clavate pleurocystidia in A. subperonatus, non-digitate pleurocystidial apices in A. sinodeliciosus, and habitat-associated macromorphological variation in A. xanthodermus. These observations extend the known morphological range of each taxon. Exploratory PCA, PERMANOVA, and trait comparisons revealed significant assemblage-level morphological structuring between the Ebinur Lake desert–wetland assemblage and the Qiongkushitai montane forest assemblage, notably in basidioma size, robustness, and basidiospore dimensions. In addition, we compiled a comprehensive identification key and species checklist for Agaricus subgen. Pseudochitonia in Xinjiang. These integrative results highlight both the diversity of subgen. Pseudochitonia in arid northwestern China and the value of combining morphological, ecological, and molecular evidence for accurate species delimitation. Full article

Unraveling rhizosphere microbial assembly and plant–microbe co-adaptation is essential for understanding how fragile mountain ecosystems respond to environmental stress. This study investigated the rhizosphere bacterial communities of Carex enervis C. A. Mey, a dominant species in arid and semi-arid alpine meadows, along an altitudinal gradient from 1160 to 1860 m. By integrating high-throughput sequencing, iCAMP-based community assembly analysis, niche differentiation assessment, and partial least squares path modeling, we examined associations among macro-environmental gradients, rhizosphere soil conditions, bacterial community assembly, and ammonium nitrogen availability. The results revealed a dual-track assembly pattern. Macro-environmental heterogeneity, particularly in elevation and precipitation, was associated with rare microbial diversity primarily through heterogeneous selection. In contrast, abundance-weighted patterns suggested homogeneous selection of core dominant microbial groups in the rhizosphere. Within several dominant genera, closely related taxa showed divergent covariation patterns rather than uniform responses along the environmental gradient, suggesting potential fine-scale differentiation in environmental responses. Path analysis further indicated that enzyme-based rhizosphere activity proxies were associated with the relative abundance of microbial response groups and with the availability of ammonium nitrogen. These findings suggest that the rhizosphere conditions of Carex enervis are associated with bacterial assembly patterns, fine-scale taxon differentiation, and nutrient-related soil variables along the elevational gradient. This study provides new insight into plant–microbe co-adaptation in arid and semi-arid mountain ecosystems. Full article

Background/Objectives: Aphids are among the most economically damaging agricultural pests globally. However, the internal phylogeny of their largest subfamily, Aphidinae, remains contentious, particularly regarding intergeneric relationships, tribal boundaries, and monophyletic status. Here, we coupled refined taxon sampling with rigorous data-filtering strategies to resolve these persistent phylogenetic discordances. Methods: We sequenced the genomes of four aphid species: Lipaphis pseudobrassicae, Rhopalosiphum maidis, Hyalopterus arundiniformis, and Uroleucon helianthicola. Integrating these new data with public genomic and transcriptomic resources, we established a comprehensive phylogenomic framework for Aphidinae. To address conflicting topologies, we compared a taxonomically broad 157-taxa dataset against a high-completeness 47-taxa core dataset. Furthermore, we evaluated the impact of intrinsic sequence properties, such as compositional heterogeneity and substitution rates, on phylogenetic conflict. Results: Our analyses demonstrate that filtering phylogenetically inconsistent loci and accounting for site heterogeneity significantly improve the topological stability of previously recalcitrant taxa. Conclusions: This study provides a refined evolutionary framework for the Aphidinae and underscores the critical importance of rigorous data curation when resolving rapid evolutionary radiations. Full article

Seashore paspalum (Paspalum vaginatum), a salinity-tolerant turfgrass, lacks well-characterized viral profiles. This study reports the discovery of a novel virus, tentatively named Paspalum latent virus (PaLV), representing a new taxon within the Alphaflexiviridae. Using high-throughput sequencing and RACE PCR, the 6995 nt genome was determined, revealing five open reading frames. Notably, PaLV lacks the AlkB domain and exhibits unique features, including overlapping start-stop codons (ORF4/ORF5) and a second in-frame AUG in the coat protein (CP) region. Phylogenetic analysis of the replicase placed PaLV in a distinct clade, separate from Potexvirus and Lolavirus. Despite low sequence identity, AlphaFold2 revealed conserved CP structural domains. Genetic analysis of 11 isolates showed low diversity and strong purifying selection. Pathogenicity assays through mechanical transmission demonstrated a broad but latent host range, including Zea mays and Sorghum spp. These findings suggest PaLV represents a novel species within a putatively new genus, Paspalovirus. Given its 90% incidence rate and latent profile, the RT-PCR assay developed here is vital for routine molecular diagnostics in turfgrass management and germplasm conservation. Full article

The floodplains of the Paraná and Paraguay rivers form the Chaco wetland, one of the most species-rich plant ecosystems in Argentina. Because wild grasses can serve as reservoirs of fungal species that cause disease and mycotoxin contamination of cereal crops, we examined asymptomatic, wild grasses from the Chaco wetlands for the presence of the genus Fusarium, which includes multiple species that cause agriculturally important diseases and/or mycotoxin contamination of crops. We focused our efforts on the identification and characterization of the multispecies lineage known as the Fusarium fujikuroi species complex (FFSC). Using morphological traits and partial DNA sequences of the TEF1 gene, we determined that 58 isolates recovered from the grasses were members of FFSC. Fifty of the isolates were identified as one of six FFSC species, including the economically important plant pathogenic species F. proliferatum, F. subglutinans, and F. verticillioides. To our knowledge, two of the species, F. anthophilum and F. pseudocircinatum, have not been reported previously in Argentina. Our analyses also indicated that eight of the FFSC isolates were a novel species, herein described as Fusarium varsavskyanum. A polymerase chain reaction (PCR) assay and genome sequence data indicate that each isolate of F. varsavskyanum isolate had only one mating type idiomorph (MAT1-1 or MAT1-2), which suggests that the fungus is heterothallic. Genome sequence analysis indicated that F. varsavskyanum has the genetic potential to produce, (i) the emerging mycotoxins fusaric acid and beauvericin (or enniatins); (ii) the pigments bikaverin, carotenoids, and fusarubin; and (iii) the plant hormones auxins, cytokinins, and gibberellins. Thus, asymptomatic grasses from the Chaco wetland can harbor Fusarium species that in some agroecosystems can cause economically important diseases and/or mycotoxin contamination of crops. It remains to be determined whether the genotypes of Fusarium species that occur on the wetland grasses, including F. varsavskyanum genotypes, can negatively impact agriculture. Full article

A new genus and species of the Cochliopidae are described from the Dudu cenote, Dominican Republic, Hispaniola Island. Shell and its measurements, soft parts morphology and pigmentation, radula, female reproductive organs, and penes are described. Mitochondrial cytochrome oxidase subunit I (COI), 16S and 12S, and nuclear 18S sequences have been applied to reconstruct phylogenetic relationships. The Hispaniolan taxon clearly belongs to a clade that also includes many Heleobia W. Stimpson, 1865, species from the Americas, the European Eupaludestrina Mabille, 1877, as well as North American Heleobops F. G. Thompson, 1968. All analyses support the assignment of the Hispaniolan taxon to a distinct genus, new to science. Its known geographic distribution is restricted to this cenote so far. Full article

The family Otididae (bustards) is one of the oldest groups of extant neoavian birds with a very patchy fossil record and almost unknown evolutionary history. This paper describes an exceptional collection of Early Pleistocene (1.8–1.6 Ma) bustards of two taxa from the Taurida cave in Crimea (Eastern Europe), which enables the first detailed morphological characterization of the poorly known large-sized species Otis lambrechti, confirming its validity and osteological distinction from the modern Great Bustard (Otis tarda). A rich sample of the smaller taxon Tetrax kalmani shows this fossil species to be consistently larger than its modern relative, the Little Bustard (Tetrax tetrax). A comprehensive critical review of Eurasian fossil Otididae, correcting previous misidentifications, is also provided. The new fossil evidence suggests that the Early Pleistocene bustard fauna of Europe was composed of morphologically distinct taxa, which were later replaced by their modern counterparts around the Middle Pleistocene, probably as a result of the mid-Pleistocene climate transition. Full article

Two new mesophotic species of Chrysymenia are reported for the Gulf of Mexico. Chrysymenia oliverhardyii sp. nov. is a broadly foliose species growing attached to rhodoliths (free-living carbonate nodules predominantly accreted by crustose coralline algae) at 58–66 m depth offshore Louisiana (northwestern Gulf) and at ~64–68 m depth in the vicinity of the Dry Tortugas, Florida (southeastern Gulf). A multi-marker phylogenetic analysis based on chloroplast-encoded rbcL and UPA, as well as nuclear LSU rDNA sequences, indicates that this taxon is most closely related to C. stanlaurelii sp. nov., a slender, branched species from the vicinity of the Florida Middle Grounds, Florida (northeastern Gulf), growing at 60 m depth. These two species from the eastern Gulf of Mexico share a basal most recent common ancestor with respect to the other known species of Chrysymenia. Illustrations and discussion are provided for the new species, as well as for the other Gulf of Mexico members C. planifrons, C. littleriana, C. halymenioides and C. nodulosa. A nomenclatural list, morphological figures, a dichotomous key, and a phylogenetic tree of pertinent Chrysymenia are provided. Full article

Callistosporiaceae is a recently established family within the suborder Tricholomatineae, encompassing tricholomatoid, collybioid or pleurotoid morphological forms. While most species of this family exhibit a saprotrophic lifestyle and have been predominantly documented in Europe and Americas, records from Asia remain comparatively sparse. In this study, Pulchragaricus rhodophyllus gen. et sp. nov., discovered in a Pinaceae and Fagaceae mixed forest in southwestern China, is described based on a comprehensive approach integrating both multigene phylogenetic analyses and morphological methods. A concatenated dataset comprising nuclear ribosomal DNA (ITS, LSU) and protein-coding genes (rpb2, tef1-α) provides robust statistical support for the placement of Pulchragaricus within Callistosporiaceae. Morphologically, this new taxon is characterized by a tomentose and yellowish-brown pileus, pink to pinkish lamellae, a solid and basally tapering stipe, broadly ellipsoid to ellipsoid basidiospores, sparse and subclavate cheilocystidia, and plentiful clamp connections. This discovery not only broadens the known diversity and distribution of the poorly documented Chinese Callistosporiaceae, but also offers a potential clue for understanding the evolutionary origins of the ectomycorrhizal symbiosis within the family. 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

Decomposing whale carcasses on the seabed (whale falls) are known to support distinct communities, with many taxa new to science. This paper describes a new polynoid species, Macellicephala irisae sp. nov., from a natural whale fall at 1240 m depth in Santa Catalina Basin off California, USA. The new species was associated with a cladorhizid sponge growing on a bone, transitioning from the sulphophilic to reef stage. We also highlight the biodiversity of exclusively deep-sea Macellicephalinae subfamily and its most species-rich genus Macellicephala. Morphological and molecular data support the description of the new species, which is also placed within a phylogenetic context using COI, 16S and 18S markers. The new species possesses distinctive filamentous notochaetae not previously reported in Macellicephala, and with the future increase in taxon coverage, an erection of new genus may be warranted. Full article

The genus Hydrochara (Coleoptera: Hydrophilidae) comprises large-bodied water beetles associated with shallow, well-vegetated freshwater habitats and is characterised by considerable taxonomic complexity. While Hydrochara caraboides is relatively well studied in western and central Europe, lineage diversity and species boundaries within the genus remain poorly resolved in eastern and south-eastern Europe. This study uses an integrative approach combining mitochondrial DNA data, morphometric analyses, and male genital morphology to investigate Hydrochara populations in continental Croatia. Specimens were collected from floodplain and lowland aquatic habitats across major river basins, morphologically identified and verified using cytochrome oxidase subunit I (16S) sequences through comparison with reference data from public databases (GenBank and BOLD). Molecular analyses confirmed the presence of H. caraboides and Hydrochara flavipes in continental Croatia. A single specimen from the upper Drava River basin (CROH030-26) formed a distinct mitochondrial lineage positioned between H. caraboides and Hydrochara dichroma in the COI phylogeny. Morphometric analyses showed extensive overlap between this specimen and H. caraboides, indicating no clear differentiation in external body size. In contrast, examination of male genitalia revealed an intermediate aedeagus morphology with transitional characters between H. caraboides and H. dichroma. Haplotype network analysis revealed a star-like structure with a dominant central haplotype shared by most H. caraboides specimens and several low-frequency variants, while the divergent specimen occupies a peripheral position, separated from the main cluster by multiple mutational steps. These results indicate that H. caraboides is a genetically heterogeneous taxon comprising multiple divergent mitochondrial lineages, suggesting that lineage diversity within this species may be underestimated. By integrating molecular and morphological evidence, this study provides new insights into the lineage diversity of Hydrochara in floodplain ecosystems of south-eastern Europe and highlights the importance of integrative approaches for resolving species boundaries and informing freshwater biodiversity conservation. Full article

Pycnospatha is a small and poorly known genus of Araceae distributed in Indochina and currently comprising only two accepted species. During botanical surveys in Si Sa Ket Province, eastern Thailand, an unusual population of Pycnospatha was discovered in a dry dipterocarp forest and found to differ from both P. arietina and P. palmata. Here, we describe this plant as a new species, Pycnospatha phanomdongrakensis. The new species is distinguished by a combination of characters, including a slender habit, shorter petiole and peduncle, a medium-sized spathe, a short and dense spadix, a distinctly curved style directed toward the apex of the spadix, a geophilous and ovoid infructescence, obovate berries, and asymmetrically ovoid seeds. The new taxon is currently known only from a single population in the Phanom Dong Rak mountain range. A preliminary conservation assessment is provided, and the species is treated as Critically Endangered (CR) following IUCN guidelines. An identification key to all species of Pycnospatha is also presented. The discovery of this new species highlights the continuing importance of field-based taxonomy in revealing overlooked aroid diversity in the seasonally dry forests of eastern Thailand. Full article

The ‘Tenuifoliae irises’ are a distinctive group of beardless, rhizomatous perennial irises, which are characterised by their somewhat vertical rhizomes, typically clothed at the apex with long maroon-brown, sharp fibrous remains of leaf sheaths; perianth tube long, filiform to scapiform; stigma bilobed; capsules often trigonous to six-ribbed, apically beaked; and seeds angulose to subcubic or pyriform, lacking fleshy appendages, and with testa hard, irregularly wrinkled. The representatives of the aggregate are mostly native to the dry steppes and grasslands from lowland to high mountain habitats of Central and Eastern Asia, extending westwards to the Black Sea and Caspian regions. Morphological classification of the ‘Tenuifoliae irises’ recognises about ten to eleven species, which are arranged into two genera, Sclerosiphon and Cryptobasis. Diverse molecular research recovered members of the ‘Tenuifoliae irises’ in contrasting placements within the ‘Iris-flower clade’. Sometimes, Sclerosiphon was sister to Eremiris, but Cryptobasis aligned with the ‘Spuria irises’ (Chamaeiris) and the ‘Spanish irises’ (Xiphion and related genera); in other cases, both Sclerosiphon and Cryptobasis formed a clade sister to Chamaeiris, or Cryptobasis alone was identified as the basal member of the Iris s.l. clade, positioned immediately after Siphonostylis. To examine these taxonomic discrepancies within a rigorous molecular systematic framework and using 12 reliably authenticated specimens, we generated 24 sequences of the matK gene (12) and the trnL (UAA)–trnF (GAA) loci (12) from members of the ‘Tenuifoliae irises’. These sequences were subsequently incorporated into a comprehensive dataset of the ‘Iris-flower clade’, enabling a broader analytical assessment. The obtained three-taxon statement hierarchy of patterns and maximum likelihood phylogenetic trees both recover the ‘Tenuifoliae irises’ as monophyletic and sister to Chamaeiris, and in turn to the ‘Xiphion s.l. clade’. We also found Sclerosiphon and Cryptobasis as sister genera. The morphological and karyological data supporting those relationships are discussed, which allow getting back to Rodionenko’s sources and recovering Sclerosiphon in his original sense, alongside Cryptobasis. Furthermore, the molecular results allow us to expand Sclerosiphon to include the Eastern Chinese members of the aggregate. In consequence, five new combinations (one series and four species) are established in the genus, one lectotype is designated, and data on nomenclature, distribution and ecology of the accepted species are reported. Full article