Taxonomic Approach Research Articles

Linking new DNA sequence data to old scientific names of Parvodinium (Peridiniopsidaceae, Dinophyceae)

ABSTRACT Parvodinium (Peridiniopsidaceae) comprises a fairly species-rich group of relatively small peridinialean dinophytes that differ only in inconspicuous traits. No DNA sequence information is available for many of these species, although such links are important for their unambiguous identification. We examined two species of Parvodinium using light and scanning electron microscopy. Sequences of the rRNA complex (including 32 new GenBank entries) were obtained and embedded in a representative taxon sample of Peridiniopsidaceae for molecular phylogenetics. Based on DNA sequence comparison the two species are closely related and comprise the sister group to Parvodinium marciniakii. The morphologies grossly matched the descriptions of Parvodinium dzieduszyckii and Parvodinium lubieniense, respectively, to which the studied materials are tentatively assigned. Our approach of integrative taxonomy provides links between morphologies and DNA sequences, filling the gaps in reference data bases that are essential in metabarcoding studies. Species of Parvodinium are not identifiable based on a single autapomorphy but rather based on a unique combination of traits. Developmental processes of both species, such as vegetative mitosis and sexual reproduction, appear similar to other species of Parvodinium, but life history of dinophytes remains understudied in general.

Assessing coastal zooplankton in the St. Lawrence estuary: spatio-temporal patterns of taxonomic and functional biodiversity.

Biodiversity assessment promotes information on the state of an ecosystem. Zooplankton, as a sentinel group at the basis of aquatic food webs, are, thus, an important component to monitor for ecosystem conservation and management. For the first time, we characterized biodiversity of coastal zooplankton along the shallow Northern shoreline of the lower St. Lawrence estuary (LSLE) using an integrated taxonomic and trait-based approach. For 3 years (2019-2021), in July and October, the zooplankton community and environmental parameters were sampled at < 35m depth. Mesozooplankton were identified at the lowest possible taxonomic level and assigned functional traits. Community structure and diversities revealed high spatio-temporal variations among three different geographic sectors and between seasons, mainly driven by water temperature, Chlorophyll-a concentration and less by salinity. Hotspots of taxonomic and functional diversities occurred in different sectors in the same month, underlining the complementarity of the two approaches. Seasonal shifts in functional diversity hotspots highlight how environmental variability affects biodiversity beyond taxonomic metrics alone. The results of our study in the LSLE establish a first robust baseline to improve our understanding of zooplankton dynamics in the coastal LSLE, to allow future tracking of ongoing change due to the increase of anthropogenic activities and climate changes and to support future monitoring efforts.

Different Approaches to Measuring Diversity Affect the Strength of the Relationship Between Biodiversity and Ecosystem Function in Freshwater Studies: A Meta‐Analysis

ABSTRACT The notion that biodiversity begets greater ecosystem functioning is an enduring paradigm in ecology, supported by a growing body of research demonstrating the significant effects of biodiversity on ecosystem functioning (BEF). These studies use several diversity metrics, which can be estimated through taxonomic, functional and molecular approaches. Here we aim to investigate the performance of different approaches (taxonomic, functional and molecular), considering the different biodiversity metrics in each approach (e.g., richness, composition, among others). Additionally, we assess the individual response of ecosystem processes (e.g., productivity, decomposition, among others) to biodiversity in each approach. To this end, we perform a review and meta‐analysis of studies that assessed BEF relationship in continental aquatic environments, encompassing 94 studies and 322 effect sizes. Our data set includes diverse contexts, with different organisms, environments and ecosystem processes. We found an overall positive association between biodiversity and the functioning of continental aquatic ecosystems (Effect size = 0.37). We also found differences in the proportions of biodiversity metrics applied in the studies between the different approaches, as well as some geographic bias, with a predominance of studies conducted in the northern hemisphere. Additionally, lakes were the most commonly studied systems, and productivity functions were frequently analysed. We found that the molecular approach, applied exclusively in microbial studies in our dataset, showed better performance in evaluating the BEF relationship. Despite the strengths of the molecular approach, it is not without limitations. Some challenges such as high costs of sequencing and maintaining database infrastructure, can hinder its application. In light of these limitations, we understand that applying functional approaches, specifically functional richness and functional evenness metrics, in the study of the BEF relationship in continental aquatic ecosystems is promising. This can be an alternative for the continuity and advancement of studies of the BEF relationship in these environments. We also highlighted the need for studies in the southern hemisphere, covering the different freshwater ecosystem and multiple functions.

Redescription and phylogeny of the little-known type species Rhinakis faurei Deroux, 1994 (Alveolata, Ciliophora, Nassophorea).

Ciliates of the class Nassophorea Small & Lynn, 1981, inhabit a wide range of aquatic environments and serve as a trophic link in microbial food webs. However, their diversity remains underestimated. In the present study, the morphology and molecular phylogeny of Rhinakis faurei Deroux, 1994, an insufficiently known nassulid ciliate, were investigated using an integrative taxonomic approach. The studied population was collected from a freshwater pond in Qingdao, China. Details of the live morphology and ciliature of R. faurei are documented for the first time, and an improved species diagnosis is provided. Phylogenetic analyses of the small subunit ribosomal RNA gene sequence revealed that R. faurei clusters within the family Nassulidae de Fromentel, 1874. However, evolutionary interrelationships within the Nassulidae remain obscure owing to under-sampling, the lack of sequence data for most nominal species, and low nodal support or unstable gene tree topologies.

Modelling the alpha and beta diversity of copepods across tropical and subtropical Atlantic ecoregions

Copepods, the most abundant individuals of the mesozooplankton, play a pivotal role in marine food webs and carbon cycling. However, few studies have focused on their diversity and the environmental factors influencing it. The objective of the present study is to model the alpha and beta diversity of copepods across the tropical and subtropical ecoregions of Atlantic Ocean using both taxonomic and functional approaches. The study used a dataset of 226 copepod species collected by stratified plankton hauls (0–800 m depth) across the tropical and equatorial Atlantic, from oligotrophic waters close to the Brazilian coast to more productive waters close to the Mauritanian Upwelling. To perform the functional analysis, six traits related to the behaviour, growth, and reproduction of copepods were selected. Several alpha diversities were estimated using taxonomic metrics (SR, Δ+, and Λ+) and functional metrics (FDis, FEve, FDiv, FOri, FSpe), and modelized with GAM model across spatial and environmental gradients, and day/night. The overall and two components of β-diversity (turnover and nestedness) were shared between depth and stations. The surface layers of stations from oligotrophic, equatorial, and Cape Verde ecoregions displayed higher values of taxonomic α-diversity. More unpredictable were the facets of functional α-diversity, although they showed a tendency to be positive with depth during the daytime. The GAM analysis revealed spatial gradients as the key factors modelling the taxonomic α-diversity, whereas depth was the most relevant for functional α-diversity. The turnover component drove taxonomic β-diversity in depth and station, whereas the nestedness component acquired relevance for the functional β-diversity. The taxonomic structure of the copepod community varied spatially across depths and ecoregions, but this was not linked to functional changes of the same magnitude.

An integrative approach to a revision of the freshwater mussel genus Songkhlanaia (Bivalvia, Unionidae), with the description of a new species.

Mainland Southeast Asia, also known as Indochina, is recognized as a global biodiversity hotspot for freshwater mussels, hosting a significant number of species and exhibiting high levels of endemism. Recently, the monotypic genus Songkhlanaia was described from the Songkhla Lake Basin in southern Thailand. In this study, two additional lineages are revealed, S.moreleti comb. nov. and S.songkhramensis sp. nov., from the Mekong Basin through an integrative taxonomic approach combining morphological characters and molecular phylogenetic analyses. The multi-locus phylogenetic inference supported the monophyly of the genus and further elucidated the sister relationship between S.moreleti and the new species, and with S.tamodienica positioned as a basal lineage. Pairwise uncorrected COI p-distances among these three species also supported the species validity and ranged from 4.2% to 8.24%. Notably, S.songkhramensis sp. nov. and S.moreleti exhibit similarities in shell morphology; however, the new species can be differentiated by more robust pseudocardinal teeth. Both species are distinguishable from S.tamodienica by their approximately twice larger size, more inflated shells, and more prominent, roughened, irregular growth lines on the shell surface. Furthermore, based on the current data, these three species are recognized as endemic and are restricted to disjunct biogeographic areas in Indochina: S.tamodienica in the Songkhla Lake Basin in southern Thailand, S.moreleti in the Tonle Sap and Lower Mekong basins, and S.songkhramensis sp. nov. in the Songkhram Basin and its nearby tributaries of the Middle Mekong Basin.

New insights in the systematics of the Hemiuroidea (Digenea: Hemiurata) based on the integrative taxonomy approach.

Opistholecithum sandugaense n. g. n. sp. was collected from the intestine of Oncorhynchus keta (Walbaum) in the Nezhinka (=Sanduga) River, Primorsky region, Russia. Based on the position of the vitellarium in hindbody and significant genetic differentiation, ten species from the genus Lecithaster Lühe, 1901 were transferred to the newly established Opistholecithum as follows: O. gibbosum (Rudolphi, 1802) n. comb., O. macrocotyle (Szidat & Graefe, 1967) n. comb., O. micropsi (Zdzitowiecki, 1992) n. comb., O. salmonis (Yamaguti, 1934) n. comb. According to the morphometrics and topology of the internal organs, O. sandugaense appears similar to O. salmonis. These species are distinct based on novel sequence data - 28S rRNA gene (p-distances 0.4%) and the cox1 mtDNA gene (p-distances 4.4-4.8%). Large-scale phylogeny reconstruction showed that the lecithasterid subfamily Lecithasterinae sensu stricto include two genera Lecithaster (type taxon) and Opistholecithum n. g.; other genera Lecithophyllum and Aponurus were transferred to the family Lecithophyllidae n. stat. Based on the morphological features, we consider four subfamilies Lecithasterinae, Trifoliovariinae, Prolecithinae and Macradenininae belonging to Lecithasteridae. Analysis of indels in the 28S divergent domains proved to be a robust technic for family delimitation within the superfamily Hemiuroidea. Especially it allows to reveal the molecular symplesiomorphies affecting phylogenetic reconstructions. Taxonomic rearrangements proposed in this study are supplemented by dichotomous keys: (1) for two genera of the subfamily Lecithasterinae; (2) for the genus Opistholecithum; (3) for the genus Lecithaster; (4) for six closely related hemiuroid families, with Lecithophyllidae n. stat. (genera Lecithophyllum, Aponurus, Monorchiaponurus, Weketrema) and Merlucciotrematidae n. fam. (Merlucciotrema).

Dactyliform appendage contributes to delayed selfing in the diminutive orchid Stigmatodactylus sikokianus

Societal Impact StatementUnderstanding plant reproductive strategies is vital for conserving endangered species. This study reveals a novel self‐pollination mechanism in the diminutive orchid Stigmatodactylus sikokianus, facilitated by the movement of a finger‐like appendage beneath the stigma. While this less‐than‐1‐mm‐long structure inspired the name Stigmatodactylus, its ecological function remained unknown for over 130 years—until now. The findings suggest that this appendage facilitates delayed self‐pollination, likely ensuring reproductive success under conditions of pollinator scarcity. Furthermore, the research highlights the value of integrating taxonomy with functional morphology to advance our understanding of pollination ecology.Summary Orchidaceae is one of the largest and most morphologically diverse plant families, largely due to intricate relationships with pollinators. However, autonomous self‐pollination is relatively common, likely as an adaptation to limited pollinator availability. This study examines the reproductive mechanism of the diminutive orchid Stigmatodactylus sikokianus, focusing on the finger‐like appendage beneath the stigma. The reproductive biology of S. sikokianus was investigated through pollination observations, artificial pollination experiments, and detailed studies of column morphology. Pollination experiments demonstrated that S. sikokianus primarily relies on autonomous self‐pollination, as indicated by high fruit set in bagged flowers and no fruit set in emasculated ones. Microscopic analysis revealed that the dactyliform appendage arcs toward the stigma, maintaining its straight structure, and eventually adheres to the stigma surface, allowing contact between the appendage apex and pollinia. UV microscopy showed thick bundles of pollen tubes penetrating the appendage adhered to the stigma and reaching the base of the column. The absence of pollen tube formation before contact between the appendage apex and pollinia suggests that autogamy occurs exclusively through the appendage at a later flowering stage. This study uncovers a novel self‐pollination mechanism in orchids, where the movement of the stigma appendage likely facilitates delayed selfing. This mechanism ensures seed production and likely reproductive success in S. sikokianus, enabling it to thrive in shaded environments with limited pollinator availability. The discovery highlights the value of integrating taxonomic and ecological approaches, as morphological traits provide valuable insights into species life histories.

Intraspecific Morphometric Variation in a New Species of Ceratomyxa Thélohan 1892 (Cnidaria) from the South Atlantic Ocean: An Ecomorphological Study Using Geometric Morphometrics.

A new species of Ceratomyxa (Ceratomyxidae, Myxosporea) was found infecting the gall bladder of the Argentine croaker Umbrina canosai Berg 1895 (Sciaenidae, Perciformes) from the Argentine sea. Using an integrative taxonomic approach that combines morphological, bioecological, and molecular analyses, we provide evidence that clearly differentiates this species from known taxa and formally describe Ceratomyxa fialai as a new species. This study is the first to apply landmark-based geometric morphometrics (GM) in myxozoan research, providing a detailed analysis of conspecific morphometric variation of ceratomyxid myxospores, examining their natural variation within and among different ceratomyxids infecting the gall bladder of U. canosai. Using GM analyses, we successfully capture and quantify phenotypic variation at the organismal level. Our results suggest that myxospore shape variation may be driven by both developmental noise and phenotypic plasticity. The work highlights the utility of GM in advancing the understanding of myxozoan morphology and its evolutionary implications and emphasizes the need for further research on myxospore shape evolution and its ecological and adaptive significance in natural populations.

A new species of Namib Day Gecko (Gekkonidae: Rhoptropus Peters, 1869) from the Serra da Neve inselberg, southwestern Angola

The genus Rhoptropus comprises nine recognized species of diurnal geckos endemic to the arid regions of Angola and Namibia. Seven species occur in Angola, including the widespread R. boultoni and the poorly known Angolan endemics R. benguellensis and R. montanus, formerly recognized as subspecies of R. boultoni. While R. benguellensis is relatively widespread in the Angolan Escarpment highlands, R. montanus is geographically restricted to the Huíla Plateau. Recent fieldwork on the Serra da Neve inselberg, a herpetological diversity hotspot in southwestern Angola, revealed the presence of an undescribed species of Rhoptropus at an elevation of approximately 1600 m. An integrative taxonomic approach combining coloration, morphological and molecular data supports the recognition of this population as a distinct taxonomic unit with affinities to R. montanus, which we describe herein as Rhoptropus nivimontanus sp. nov. The discovery of a new species of Rhoptropus endemic to Serra da Neve is discussed in the biogeographic context of the region.

Two new species of ectoparasitic microfungi within the Hesperomyces virescens complex from Algeria, Italy, and Malaysia

Arthropods are hosts to a variety of parasitic fungi, including those within the order of Laboulbeniales (Ascomycota, Laboulbeniomycetes). Species in the genus Hesperomyces are specialized in growing on ladybirds (Coccinellidae). Recent studies have uncovered multiple cryptic species within the Hesperomyces virescens species complex. They found that these species are segregated not only by host, but also by a geographic component. Here, we describe two new species in this species complex, based on morphological, molecular phylogenetic, ecological, and geographical evidence: Hesperomyces chilocori-bipustulati sp. nov. on Chilocorus bipustulatus from the Mediterranean region, and He. coccinellae-transversalis sp. nov. on Coccinella transversalis from Peninsular Malaysia. Hesperomyces chilocori-bipustulati is the second species known to associate with a representative of the genus Chilocorus, after He. virescens sensu stricto which was described from Ch. stigma from the USA. The findings of this paper contribute to our understanding of the diversity, host specificity, and biogeographical distribution within the Hesperomyces virescens species complex and highlight the need for further integrative taxonomy approaches in Laboulbeniales.

A new species of Astragalus (Fabaceae) from the Irano-Turanian biodiversity hotspot: an integrative approach

BackgroundThe genus Astragalus is the largest and one of the most diverse genera of flowering plants, particularly in the Northern Hemisphere, with a significant concentration of species in the Irano-Turanian region. Within this genus, section Hymenostegis is notable for its complexity and high levels of endemism, especially in northwestern Iran. During recent field explorations in West Azarbaijan province, a distinct population of Astragalus was identified, differing from known species within section Hymenostegis. This study aimes to describe and analyze this new species and clarify its relationship with closely related taxa using an integrative approach.ResultsAstragalus kuzehrashensis sp. nov. is described following detailed morphological comparisons with its closest relatives, A. chehreganii and A. hakkianus. The new species is distinguished by unique stipule characteristics, leaflet shape, inflorescence structure, and seed micromorphology. Molecular phylogenetic analysis using ITS and ycf1 sequences reveals that A. kuzehrashensis forms a clade with A. chehreganii and A. hakkianus, although it exhibits genetic differences. Genome size estimation confirms that A. kuzehrashensis is hexaploid (2n = 6x = 48), aligning it more closely with A. hakkianus than with the tetraploid A. chehreganii. The distinct morphological characters and genomic data support recognizing A. kuzehrashensis as a new species within section Hymenostegis.ConclusionsThe identification of A. kuzehrashensis underscores the importance of an integrative taxonomic approach, combining morphological, molecular, and cytogenetic data to resolve species boundaries within complex groups like Astragalus section Hymenostegis. This study highlights the rich biodiversity of the Irano-Turanian floristic region, emphasizing the need for ongoing exploration and conservation efforts, particularly in areas of high endemism. Our findings contribute to a deeper understanding of the taxonomy and evolutionary relationships within the genus Astragalus.

Comparative species delimitation of a biological conservation icon.

The United States Endangered Species Act (ESA) of 1973 set a precedent for biodiversity conservation across the globe.1 A key requirement of protections afforded by the ESA is the accurate delimitation of imperiled species. We present a comparative reference-based taxonomic approach to species delimitation that integrates genomic and morphological data for objectively assessing the distinctiveness of species targeted for protection by governmental agencies. We apply this protocol to the Snail Darter (Percina tanasi), a freshwater fish from the Tennessee River that was discovered in 1973 and declared an endangered species under the ESA in 1975.2 Concurrently, the Snail Darter's habitat was slated to be destroyed through the construction of the Tellico Dam by the Tennessee Valley Authority (TVA),3,4 inspiring nationwide protests advocating for the suspension of the federal project. This David versus Goliath struggle between supporters of the 3-inch fish and the TVA culminated in the first major legal conflict over protections afforded by the ESA, the US Supreme Court case Hill v. TVA, 437U.S. 153 (1978), with a 6 to 3 ruling in favor of protecting the Snail Darter and interrupting the completion of the Tellico Dam. Here, we integrate multiple lines of evidence in a comparative framework to demonstrate that despite its legacy, the Snail Darter is not a distinct species but is a population of the Stargazing Darter (Percina uranidea) described in 1887. These results illustrate how a reference-based framework for species delimitation dramatically aids the proper direction of efforts toward protecting biodiversity.

Novel contribution to the taxonomy and molecular phylogeny of scuticociliates (Protozoa): Resolving the non-monophyly of the genus Paranophrys Thompson and Berger, 1965 and the establishment of the genus Anteparanophrys n. gen.

During a field survey of parasitic ciliates diversity in South Korea, a scuticociliate was found in a water sample collected during scuba diving. At first glance, the species looks similar to members of the genus Paranophrys especially P. magna but they differ mainly in the body size and the number of somatic kineties. Thus, integrative taxonomic approaches (i.e., silver impregnations, scanning electron microscopy, and molecular phylogeny) were applied and confirmed that the isolate is a new species. Detailed comparison between the new species and the three members of the genus Paranophrys revealed that the new species is similar to P. magna in having membranelle 1 slightly shorter than membranelle 2 and the monokinetids are randomly scattered between dikinetids within each somatic kinety. On the other hand, membranelle 1 in both P. marina (type species) and P. thompsoni is about three times longer than membranelle 2 and their ciliary rows invariably consist of dikinetids anteriorly and monokinetids posteriorly. Observations on the feeding behavior and habitat suggest that the new species is facultative histophagous. Phylogenetic analyses based on 18S rRNA gene indicate that the new species and P. magna belong to the newly established genus Anteparanophrys n. gen. i.e., Anteparanophrys koreana n. sp. and Anteparanophrys magna (Borror, 1972) n. comb.

Phenylobacterium ferrooxidans sp. nov., isolated from a sub-surface geothermal aquifer in Iceland.

A novel bacterial strain, HK31-GT, was isolated from a subsurface geothermal aquifer (Hellisheidi, SW-Iceland) and was characterized using a polyphasic taxonomic approach. Phylogenetic analysis of 16S rRNA gene along with phylogenomic position indicated that the novel strain belongs to the genus Phenylobacterium. Cells are motile Gram-negative thin rods. Physiological characterization showed that strain HK31-GT is a mesophilic bacterium able to grow from 10 to 30°C, at pH values between 6 and 8 and at NaCl concentrations between 0 and 0.5%. Optimal growth was observed without sodium chloride at 25°C and pH6. Strain HK31-GT is chemoorganoheterotroph and its major saturated fatty acids are C18:1ω7c, C16:1ω6c and C16:0, the predominant quinone is Q-10 and the major polar lipid is phosphatidylglycerol. The new strain also possesses the capacity to use ferrous iron (Fe(II)) as the sole energy source and can also be considered as a chemolithoautotrophic microorganism. The overall genome of strain HK31-GT was estimated to be 4.46 Mbp in size with a DNA G+C content of 67.95%. Genes involved in iron metabolism were identified, but no genes typically involved in Fe(II)-oxidation were found. According to the overall genome relatedness indices (OGRI) values, six MAGs from groundwater have been assigned to the same species as the new strain HK31-GT. Furthermore, OGRI values between the genome of strain HK31-GT and the genomes of its closest relatives are below the species delineation threshold. Therefore, given the polyphasic approach used, strain HK31-GT represents a novel species of the genus Phenylobacterium, for which the name Phenylobacterium ferrooxidans sp. nov. is proposed. The type strain is HK31-GT (DSM 116432T=UBOCC-M-3429T=LMG 33376T).

Deciphering the Patterns and Correlates of Zooplankton Functional Diversity in Mountain and Lowland Ponds

ABSTRACT Biodiversity studies have usually been conducted considering only the taxonomic dimension of ecological communities. However, diversity measurements taking into account the functional traits of species may be more sensitive in capturing aspects of community functioning that are not apparent with the more traditional taxonomic approach. Functional diversity (either based on alpha or beta diversity levels) is, therefore, a facet of diversity that provides a link between ecosystem functioning and community structure and may be an important metric for assessing the impact of global change in the context of applied conservation schemes. Zooplankton is a key element of lentic ecosystems due to its linkage between primary producers and secondary consumers. Here, we tried to disentangle the spatial patterns and correlates of zooplankton functional alpha and beta diversity along a relatively wide altitudinal gradient (700–2100 m a.s.l.) across central and northwestern Spain. We also identified key environmental controls of zooplankton functional alpha diversity across an extensive set of lowland (48) and mountain (28) ponds sampled in 2004–2005 and 2007–2008, respectively. We also assessed whether replacement or richness differences drove overall functional beta diversity patterns and evaluated the relative contributions of geographical and environmental distances to spatial variation in functional diversity. Our findings highlighted the importance of environmental filtering with increasing elevation, leading to a potentially concomitant decrease in functional alpha diversity values. However, altitudinal variation was not related to changes in functional beta diversity patterns, which were mostly the result of the pure loss or gain of species traits both in lowland and mountain ponds. We suggest that eutrophication associated with agricultural development was the main factor underlying the functional homogenisation of zooplankton communities in lowland ponds. Local environmental filtering was more strongly associated with functional beta diversity and its dominant trait richness difference component than with geographical distances. This study supports the prediction that elevation fosters changes in different aspects of the variation of zooplankton community functions. Our results highlighted the importance of local conditions determining the functional architecture of zooplankton communities, both in physiologically extreme environments (mountains) and in lowland areas suffering from agricultural pressures and associated eutrophication processes. However, the fraction characterising relationships between functional diversity and environmental correlates was generally low. This suggests the prevalence of idiosyncratic responses and random stochastic events in structuring variation of trait composition in freshwater zooplankton communities.

Pseudomonas retamae sp. nov., a novel endophytic bacterium with plant growth-promoting potential, isolated from root nodules of Retama monosperma in Northwestern Algeria.

A thorough polyphasic taxonomic study, integrating genome-based taxonomic approaches, was carried out to characterize the RB5T strain isolated from root nodules of Retama monosperma growing on the coastal dunes of Bousfer Beach (Oran, Algeria). The 16S rRNA gene sequence analysis revealed that strain RB5T had the highest similarity to Pseudomonas granadensis LMG27940T (98.94%) and Pseudomonas gozinkensis IzPS32dT (98.73%). Phylogenetic studies, including both 16S rRNA gene sequence and multilocus sequence analysis using 16S rRNA, gyrB and rpoD housekeeping genes, positioned RB5T in a distinct branch alongside its closest relative, P. granadensis LMG27940T. Phylogenomic analysis using the Bac120 marker set and Type (Strain) Genome Server confirmed the unique position of RB5T and its close relationship with P. granadensis LMG27940T. Similarly, genomic comparisons using average nucleotide identity based on blast (ANIb) and digital DNA-DNA hybridization (dDDH) revealed values of 92.85 and 59.3%, respectively, when compared with its closest relative, P. granadensis LMG27940T. Both values fall below the established species delimitation thresholds of 95-96% for ANIb and 70% for dDDH, providing strong genomic evidence that strain RB5T represents a novel species. Further average nucleotide identity comparisons with unclassified Pseudomonas spp. (384 genomes) and metagenomic-derived genomes from the Genome Taxonomy Database (GTDB) showed values between 84.27 and 89.2%, indicating that strain RB5T belongs to a unique evolutionary line. The genome of RB5T, with a size of 6 311 310 bp and a G+C content of 60%, harbours several key genes associated with plant growth-promoting traits, making it a promising candidate for sustainable agriculture. Phenotypically, RB5T strain is an aerobic, rod-shaped, Gram-negative, non-spore-forming bacterium that is motile with a single polar flagellum. It grows under a wide range of temperature (4-42 °C) and pH (5-10) conditions and tolerates up to 6% (w/v) NaCl. The main cellular fatty acid composition of RB5T includes C16:0, C17:0 cyclo and the summed features 3 consisting of C16:1 ω7c/C16:1 ω6c. Based on the phylogenetic, phenotypic, chemotaxonomic and genome comparison analyses, strain RB5T was identified as a novel species of the genus Pseudomonas, for which the name Pseudomonas retamae sp. nov. is proposed. The type strain is RB5T (=DSM 117471T=LMG 33633T=CIP 112482T).

Flavobacterium aerium sp. nov., a bacterium isolated from the air of the Icelandic volcanic island Surtsey.

A novel bacterium, designated 19SA41, was isolated from the air of the Icelandic volcanic island Surtsey. Cells of strain 19SA41 are Gram-stain-negative, strictly aerobic, non-motile rods and form pale yellow-pigmented colonies. The strain grows at 4-30 °C (optimum, 22 °C), at pH 6-10 (optimum, pH 7.5) and with 0-4% NaCl (optimum, 0.5%). Phylogenetic analyses based on 16S rRNA gene sequences showed that 19SA41 belonged to the genus Flavobacterium and is most similar to Flavobacterium xinjiangense DSM 19743T, with a sequence similarity of 96.52%. The new strain contained iso-C15 : 0 (22%) and summed feature 3 (C16∶1ω6c/C16∶1ω7c) (20%) as the predominant fatty acids. The major respiratory quinone was menaquinone-6 (100%). The polar lipid profile consisted of phosphatidylethanolamine and several uncharacterized amino lipids, glycolipids and lipids. The genome of the new strain was 4.01 Mbp, and its G+C content was 33.2 mol%. Based on characterization and comparative results, using a polyphasic taxonomic approach, we propose that the new isolate represents a novel species of the genus Flavobacterium with the name Flavobacterium aerium sp. nov. The type strain is ISCaR-07695T (=DSM 116640T =UBOOC-M-3567T).

Three new species of the spider genus Naphrys Edwards (Araneae, Salticidae) under morphology and molecular data with notes in the distribution of Naphrys acerba (Peckham & Peckham) from Mexico.

Herein, we describe three new species of the spider genus Naphrys Edwards, 2003 from Mexico: Naphrys echeri sp. nov., Naphrys tecoxquin sp. nov., and Naphrys tuuca sp. nov. An integrative taxonomic approach was applied, utilizing data from morphology, ultra-morphology, the mitochondrial gene COI, and distribution records. Four molecular methods for species delimitation were implemented under the corrected p-distance Neighbor-Joining (NJ) criteria: (1) Assemble Species by Automatic Partitioning (ASAP); (2) general mixed Yule coalescent (GMYC); (3) Bayesian Poisson tree process (bPTP); and (4) multi-rate Poisson tree process (mPTP). Both morphological and molecular data supported the delimitation and recognition of the three new species. The average interspecific genetic distance (p-distance) within the genus Naphrys is 14%, while the intraspecific genetic distances (p-distance) is <2% for most species. We demonstrate that the natural distribution of Naphrys is not restricted to the Nearctic region. Furthermore, the reported localities herein represent the first with precise locations in the country for Naphrys acerba. In addition, a taxonomic identification key is provided for the species in the genus.

Cuticular composition: An alternative taxonomic approach to differentiate between Argas arboreus and Argas persicus ticks (Acari: Argasidae)

Argas arboreus and A. persicus are blood sucking ectoparasites on domestic birds in Egypt. They cause anemia in birds, in addition to transmitting a variety of pathogens that leads to economical loss in the poultry industry. It is difficult for non-taxonomists to differentiate between these species because of minor morphological characters. Therefore, it is very important to identify tick species for developing a suitable strategy to reduce risks to poultry wealth. This study characterized the female cuticular hydrocarbons of two Argas species using gas chromatography-mass spectrometry. Sixty different hydrocarbons were exclusively identified in A. arboureus, whereas only 51 in A. persicus. Some of the hydrocarbon compounds were stage-specific ones that differentiate between two species. Others shared between all feeding stages of both species that improved they are closely related ones. Genetic variability recorded its maximum value between unfed stages of the two species, and similarity reached only 25%. The present study provides the first chemotaxonomic data to differentiate between two closely related Argas species according to their cuticular hydrocarbons. Therefore, hydrocarbon composition seems to be a promising tool available as a taxonomic character, in addition improved that feeding stage was the susceptible one to be controlled.