Phylogenetic Investigations Research Articles

Molecular phylogenetic studies on Trigonella section Ellipticae (Trifolieae, Fabaceae) from India utilising nrDNA (ITS) and cpDNA (trnL–trnF & petL–psbE)

This study highlights the critical importance of species delimitation in biodiversity conservation, focusing on the poorly understood Indian Trigonella species, with focus on T. sect. Ellipticae. Despite their ecological and socio-economic significance, these species, primarily found in the northwest Himalayas, have been inadequately catalogued and preserved. Adapted to harsh, dry environments, T. sect. Ellipticae exhibits morphological traits that complicate traditional species delimitation due to significant overlap among species boundaries. To address these challenges, we integrated molecular sequence data (nrDNA ITS and cpDNA (trnL–trnF & petL–psbE)) with morphological analysis, confirming the monophyly of Trigonella and revealing distinct evolutionary lineages within T. sect. Ellipticae. While nrDNA ITS sequences alone proved insufficient for resolving species relationships, phylogenetic investigations utilizing plastid data identified three distinct clades, enhancing taxonomic clarity. The study also suggests that observed morphological variations in T. cachemiriana may be due to phenotypic plasticity rather than distinct evolutionary lineages. We propose a new combination, T. emodi var. gracilis, to better represent the diversity within this group. Overall, this research underscores the necessity of combining molecular and morphological approaches for effective species delimitation, contributing to broader biodiversity conservation efforts in India, where many species remain inadequately catalogued. As the urgency for conservation increases, refining taxonomic frameworks is essential for ensuring that conservation strategies are based on accurate biological data.

A new computational method to estimate adaptation time in Avicennia by using divergence time

Evolutionary studies of plant groups which are distributed in vast geographical regions and face different ecological and environmental conditions are important as they through light on different mechanisms of local adaptation and species divergence through time. The genus Avicennia is one of these plant groups which inspire of few species show interesting geographical distribution with some degree of species-specific geographical isolations. In general, very limited molecular phylogenetic investigations have been carried out in the genus Avicennia, and therefore we conducted the present study with the following aims:To estimate the species divergence time based on different nuclear and chloroplast DNA regions, separately. This will illustrate how different genetic regions evolved in this genus,To identify the sequences with potential adaptive value against geographical variable by latent factor mixed models (LFMM) analysis,To illustrate the phylogenetic signal of these DNA regions and their role in speciation within the genus and,To introducing a new computational strategy for estimating adaptive time for the sequences. The results showed that different genetic regions may produce different species divergent time, both the nuclear ribosomal internal transcribed spacer (ITS) region and chloroplast DNA sequences, contained potentially adaptive single nucleotide polymorphisms (SNPs).We could present a suggestive time for these adaptive sequences for the first time. In conclusion both local adaptation and independent mutations seem to have played role in Avicennia speciation and evolution.

High-quality genome of a novel Thermosynechococcaceae species from Namibia and characterization of its protein expression patterns at elevated temperatures.

Thermophilic cyanobacteria thrive in extreme environments, making their thermoresistant enzymes valuable for industrial applications. Common habitats include hot springs, which act as evolutionary accelerators for speciation due to geographical isolation. The family Thermosynechococcaceae comprises thermophilic cyanobacteria known for their ability to thrive in high-temperature environments. These bacteria are notable for their photosynthetic capabilities, significantly contributing to primary production in extreme habitats. Members of Thermosynechococcaceae exhibit unique adaptations that allow them to perform photosynthesis efficiently at elevated temperatures, making them subjects of interest for studies on microbial ecology, evolution, and potential biotechnological applications. In this study, the genome of a thermophilic cyanobacterium, isolated from a hot spring near Okahandja in Namibia, was sequenced using a PacBio Sequel IIe long-read platform. Cultivations were performed at elevated temperatures of 40, 50, and 55°C, followed by proteome analyses based on the annotated genome. Phylogenetic investigations, informed by the 16S rRNA gene and aligned nucleotide identity (ANI), suggest that the novel cyanobacterium is a member of the family Thermosynechococcaceae. Furthermore, the new species was assigned to a separate branch, potentially representing a novel genus. Whole-genome alignments supported this finding, revealing few conserved regions and multiple genetic rearrangement events. Additionally, 129 proteins were identified as differentially expressed in a temperature-dependent manner. The results of this study broaden our understanding of cyanobacterial adaptation to extreme environments, providing a novel high-quality genome of Thermosynechococcaceae cyanobacterium sp. Okahandja and several promising candidate proteins for expression and characterization studies.

Extinct or Not? Confirming the “Extinct” Status of Hieracium tolstoii (Asteraceae) with Integrated Taxonomic Investigation

Hieracium is one of the largest flowering plant genera that has recently experienced a rapid evolutionary radiation. Due to the massive morphological variation among species, frequent hybridization, and polyploidization events, combined with apomictic reproduction in polyploids, the concept of species in Hieracium is widely debated, and species identification is incredibly challenging. Taxonomic investigation can lead to changes in conservation status or, in some cases, to de-extinctions of species. Taxa with doubtful classification are particularly sensitive to this kind of problem. Hieracium tolstoii was a narrow Italian endemic species that is nowadays considered extinct. Described as a morphological intermediate form between two other species, no further investigations were conducted after its first description. To clarify H. tolstoii’s origin and ensure the validity of its current conservation status, we conducted a taxonomic investigation on herbaria specimens of the early XX century. Specimens were studied using a morphometric analysis that compared H. tolstoii with other closely related taxa. Moreover, we performed phylogenetic investigations using three plastid intergenic spacers to evaluate the relationship between species. Plastid markers revealed the presence of indels and SNPs in H. tolstoii sequences that differ from sequences of the supposed parental species. Morphometry revealed differences among species that led us to confirm the validity of H. tolstoii as an independent apomictic species and, therefore, unfortunately, its extinction.

Kssdtree: an interactive Python package for phylogenetic analysis based on sketching technique.

Sketching technologies have recently emerged as a promising solution for real-time, large-scale phylogenetic analysis. However, existing sketching-based phylogenetic tools exhibit drawbacks, including platform restrictions, deficiencies in tree visualization, and inherent distance estimation bias. These limitations collectively impede the overall convenience and efficiency of the analysis. In this study, we introduce Kssdtree, an interactive Python package designed to address these challenges. Kssdtree surpasses other sketching-based tools by demonstrating superior performance in terms of both accuracy and time efficiency on comprehensive benchmarking datasets. Notably, Kssdtree offers key advantages such as intra-species phylogenomic analysis and GTDB-based phylogenetic placement analysis, significantly enhancing the scope and depth of phylogenetic investigations. Through extensive evaluations and comparisons, Kssdtree stands out as an efficient and versatile method for real-time, large-scale phylogenetic analysis. The Kssdtree Python package is freely accessible at https://pypi.org/project/kssdtree and source code is available at https://github.com/yhlink/kssdtree. The documentation and instantiation for the software is available at https://kssdtree.readthedocs.io/en/latest. The video tutorial is available athttps://youtu.be/_6hg59Yn-Ws.

First Molecular Diagnosis of Oestrus ovis (Linnaeus, 1758) Larvae Causing Conjunctival Ophthalmomyiasis in Mexico City, Mexico.

Human ophthalmomyiasis is a rare ocular parasitosis that results from the accidental infestation of dipteran larvae of several species, including Oestrus ovis (Linnaeus, 1758). This study aims to present the fourth documented human case of ophthalmomyiasis in Mexico, identifying the etiological agent through morphological and molecular analyses. Additionally, we investigated the phylogenetic position and genetic distances among different specimens globally characterized based on mitochondrial Cox1 sequences. A total of five larval specimens were extracted from the patient's eye, with two specimens allocated for identification based on morphological features using a stereomicroscope, and the remaining three preserved in absolute ethanol, one of them used for subsequent analysis using molecular methods. The mitochondrial Cox1 region was amplified and sequenced using automated Sanger sequencing. The resulting sequence was deposited in GenBank under accession number OR440699 and subjected to BlastN analysis against 35 other Cox1 sequences of O. ovis from GenBank. The identity and phylogenetic position of the strains were further explored using parsimony and maximum likelihood phylogenetic methods. Morphological examination of the larval specimens extracted from the patient's eye unequivocally identified them as O. ovis species. BlastN analysis and comprehensive phylogenetic investigations involving a total of 36 Cox1 sequences confirmed the taxonomic identity of the larvae. Notably, our sequence was positioned within the cluster formed by the Brazilian and two Iranian samples. This finding underscores a shared genetic ancestry among these distinct geographical isolates and provides valuable insights into the evolutionary relationships within O. ovis populations. The presence of O. ovis infestation in Mexico City suggests potential shifts in environmental conditions favoring fly proliferation, highlighting the need for vigilance in urban healthcare settings.

The plastome and phylogenetic status of Cotoneaster rosiflorus (Rosaceae)

Endemic to Taiwan Province, China, Cotoneaster rosiflorus Kun-Cheng Chang & Fu-Yuan Lu 2011 (Rosaceae) holds significant ecological and ornamental importance. Despite its value, research on its molecular data and phylogenetic position has remained limited. In this study, we addressed this gap by sequencing the genome-skimming data, assembling its plastome, and investigating its phylogenetic position. The plastome, spanning 159,449 bp in length, consisted of a large single-copy (87,433 bp), a small single-copy (19,262 bp), and two inverted repeat regions (26,377 bp). We annotated a total of 128 functional genes, including 84 protein-coding genes, 36 transfer genes, and eight ribosomal RNA genes. The phylogenetic results indicated that C. rosiflorus is closely related to C. dammerii, suggesting that C. rosiflorus might have captured its chloroplast from C. dammerii through hybridization and introgression events. This study offered valuable insights for forthcoming phylogenetic and population genetic investigations of Cotoneaster.

The complete chloroplast genome sequence of Lemna turionifera (Araceae)

Lemna turionifera is native to North America and northern Asia, with significant potential for industrial wastewater remediation. The complete nucleotide sequence of the L. turionifera chloroplast genome (cpDNA) was determined. The cpDNA is a circular molecule of 166,606 bp and containing a pair of inverted repeats (IRs) measuting 31,663 bp each. These IRs are flanked by a small single-copy region of 13,542 bp and a large single-copy region of 89,738 bp. The chloroplast genome of L. turionifera consisted of 112 unique genes, including 78 protein-encoding genes, 30 tRNA genes, and four rRNA genes. The phylogenetic analysis utilizing cpDNA provided a well-supported resolution of the relationships among subfamilies within the Araceae family. Our findings indicated a close relationship between L. turionifera and a clade consisting of L. minor, L. japonica, and L. gibba. The availability of the complete chloroplast genome sequence of L. turionifera presents valuable data for future phylogenetic investigations within the Lemnaceae family.

Morphologic and phylogenetic investigations revealed size-divergent clades in chelae morphotypes of freshwater prawn Macrobrachium vollenhovenii Herklots (Decapoda: Palaemonidae) in a lake and river system of Southwest Nigeria

BackgroundThe freshwater prawn Macrobrachium vollenhovenii is one of the largest Macrobrachium species, a biological agent against human schistosomiasis, and a cheap protein source in riverine communities in West Africa. However, its aquaculture development for sustainable utilization is challenged by cryptic identity amidst the presence of morphotypes of unknown size and genetic relatedness. This study aimed to investigate the maximum sizes and evolutionary links of chelae morphotypes in M. vollenhovenii for precise identification and utilization in a 3 × 2 randomized block experimental design. Ninety biggest encountered samples of M. vollenhovenii chelae morphotypes—those possessing equal left and right side chelae, longer left chelae, and shorter left chelae—were obtained from fisherfolks’ catches at each of Asejire Lake and Ogun River during peak seasons (July–September) bimonthly field survey, representing EAAL, LLAL, SLAL—GAALs, and EAOR, LLOR, SLOR—GAORs. These were analyzed for differences (p < 0.05) in size-linked parameters—length (L (cm)), weight (W (g)), and condition factor (K). Specimens’ 16S rRNA nucleotide sequences were utilized to infer phylogenetic linkages, single-nucleotide polymorphism (SNP), and amino acid translations alongside NCBI references (NCBIrefseq).ResultsWeight (W) and condition factor (K), among GAALs, for SLAL and LLAL were similar; EAAL was significantly lowest; among GAORs, SLOR and LLOR were similar; and EAOR was significantly lowest. In GAALs, EAAL, LLAL, and SLAL had higher L, W, and K than counterpart GAORs. Sequences formed two polyphyletic groups: EAOR branch from EAAL, in which 100.0%EA rooted 75.0% NCBIrefseqs, forming a clade; and GAOR-SLOR and LLOR branch form GAOR-LLAL rooted SLAL, in which 100.0%LL and SL rooted KJ463387.1 (Badagry), forming another clade. SNP Locus 91 separated 100.0%GAOR from 100.0%GAAL and 100.0%NCBIrefseqs translating to valine; SNP Locus 171 separated 100.0%EA and its co-rooted NCBIrefseqs from 100.0%LL, SL, and their co-rooted NCBIrefseq, translating to glycine/glutamic acid change.ConclusionThe equal left and right side chelae and the unequal left and right side chelae specimens are, respectively, small- and robust-sized, irrespective of habitat. They are divergent size-linked clades having protein translate differences, delineable at 16S rRNA SNP Locus 171; their size variant habitat strains are delineable at SNP Locus 91. These SNP markers will be useful for precision identification and selection of the size variant chelae morph strains for sustainable utilization.

The Complete Chloroplast Genome of Syzygium syzygioides (Myrtaceae: Myrtales) and Phylogenetic Analysis

Abstract Background: Syzygium syzygioides (Miq.) Merr. and L. M. Perry is a common medicinal plant species known for its biologically active compounds. However, the chloroplast (cp) genome of S. syzygioides has not been previously reported. This study aimed to determine the complete cp genome sequence of S. syzygioides and investigate its phylogenetic relationships within the Syzygium genus. Methods: Leaf samples of S. syzygioides were collected from Vietnam, and the complete cp genome was sequenced and assembled. Phylogenetic analyses were then conducted to examine the evolutionary relationships between S. syzygioides and other Syzygium species. Results: The cp genome of S. syzygioides was found to be 158,172 base pairs in length, with a GC content of 37.0%. Phylogenetic reconstruction based on the cp genome data revealed that S. syzygioides is closely related to 10 other Syzygium species, including Syzygium buettnerianum, Syzygium bamagense, Syzygium grande, Syzygium megacarpum, Syzygium glomeratum, Syzygium claviflorum, Syzygium tsoongii, Syzygium fluviatile, Syzygium buxifolium, and Syzygium grijsii. Conclusions: This study provides the first report of the complete cp genome sequence of S. syzygioides, a medicinally important plant species in the Myrtaceae family. The phylogenetic analysis using the cp genome data sheds light on the evolutionary relationships within the Syzygium genus, which is the largest genus in the Myrtaceae. The new molecular data generated in this study can be used for the molecular identification and further phylogenetic investigations of Syzygium species, contributing to a better understanding of the diversity and evolutionary history of this economically and ecologically significant plant group.

DNA barcoding for identification of forensically important synanthropic flesh flies (Diptera: Sarcophagidae) from Eastern India

ABSTRACT Sarcophagidae is a significant Diptera family because several of its species are among the first to visit a corpse, and it helps in minPMI estimation. Sarcophagidae species identification for a layman is difficult due to identical morphological appearance and if the fly is a female. Also, fly specimens get damaged due to improper storage of forensic specimens collected from crime scenes. Thus, in this study, we aimed to check the efficiency of cytochrome oxidase 1 (COI) for identifying eleven sarcophagid flies species. Flesh flies were collected from various biogeographic regions of West Bengal. COI barcodes successfully differentiated between species with a very significant K2P interspecific genetic divergence, which ranged between 3.12% and 20.11%, and intraspecific genetic divergences ranged from 0% to 1%. The subgenera Uroxanthisca and Sinonipponia are used in the phylogenetic analysis for the first time in the oriental context. Phylogenetic analysis was performed using a Neighbour Joining (NJ) tree constructed using Kimura two-parameter (K2P) in MEGA X software. Thus, COI barcodes proved to be quite effective as an alternate method of identifying flesh fly species, and future studies should include additional markers for further phylogenetic investigations of the Sarcophagidae family.

A rare waterborne outbreak of Bacillus paranthracis in Shandong province, China, 2020: epidemiologic survey, genomic insights, and virulence characteristics

ABSTRACT Bacillus paranthracis, a Gram-positive conditional pathogen of Bacillus cereus group species, is capable of causing foodborne and waterborne illnesses, leading to intestinal diseases in humans characterized by diarrhoea and vomiting. However, documented cases of B. paranthracis infection outbreaks are rare in the world, and the genomic background of outbreak strains is seldom characterized. This study retrospectively analyzed strains obtained from an outbreak in schools, as well as from water systems in peri-urban areas, China, in 2020. In total, 28 B. cereus group isolates were retrieved, comprising 6 from stool samples and 22 from water samples. Epidemiological and phylogenetic investigations indicated that the B. paranthracis isolate from drinking water as the causative agent of the outbreak. The genomic comparison revealed a high degree of consistency among 8 outbreak-related strains in terms of antimicrobial resistance gene profiles, virulence gene profiles, genomic content, and multilocus sequence typing (MLST). The strains related to the outbreak show highly similar genomic ring diagrams and close phylogenetic relationships. Additionally, this study shed light on the pathogenic potential and complexity of B. cereus group through its diversity in virulence genes and mice infection model. The findings highlight the usefulness of B. paranthracis genomes in understanding genetic diversity within specific environments and in tracing the source of pathogens during outbreak situations, thereby enabling targeted infection control interventions.

Historical Review of Sugarcane Streak Mosaic Virus that Has Recently Emerged in Africa.

Sugarcane streak mosaic virus (SCSMV), now assigned to the genus Poacevirus of the family Potyviridae, was reported for the first time in 1932 in Louisiana and was believed to be strain F of sugarcane mosaic virus (SCMV) for more than six decades. SCMV-F was renamed SCSMV in 1998 after partial sequencing of its genome and phylogenetic investigations. Following the development of specific molecular diagnostic methods in the 2000s, SCSMV was recurrently found in sugarcane exhibiting streak mosaic symptoms in numerous Asian countries but not in the Western hemisphere or in Africa. In this review, we give an overview of the current knowledge on this disease and the progression in research on SCSMV. This includes symptoms, geographical distribution and incidence, diagnosis and genetic diversity of the virus, epidemiology, and control. Finally, we highlight future challenges, as sugarcane streak mosaic has recently been found in Africa, where this disease represents a new threat to sugarcane production.

The complete mitochondrial genome of Tauraco livingstonii (Musophagidae: Tauraco)

Livingstone’s turaco, Tauraco livingstonii, belongs to the family Musophagidae. In this study, we obtained the complete mitochondrial genome sequence of Livingstone’s turaco by high-throughput sequencing technology and constructed a phylogenetic tree. It was found that the mitochondria of this species are 19,015 bp in length and contain a total of 37 genes, comprising 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. The base composition of the mitochondrial genome is 31.61% A, 24.22% T, 30.64% C, and 13.52% G, with a GC content of 44%. Notably, an intriguing phenomenon of mitochondrial genome rearrangements was observed, characterized by the duplication of the tRNA Glu-L-CR gene order. In addition, the results of the phylogenetic tree analysis shed light on the taxonomic position of Livingstone’s turaco and supported the taxonomy of Otidimorphae. The study provides a basis for future phylogenetic and taxonomic investigations of Musophagiformes.

The complete chloroplast genome and phylogenetic analysis of Bauhinia glauca subsp. hupehana (Craib) T. C. Chen 1988

Bauhinia glauca subsp. hupehana (Craib) T. C. Chen 1988, a member of the Leguminosae family, Cercidoideae subfamily, and Bauhinia genus, has a rich history of traditional usage in Chinese medicine. Renowned for its analgesic properties, it is commonly employed for managing inflammation and pain. This study aimed to sequence the complete chloroplast genome of B. glauca subsp. hupehana using Illumina paired-end sequencing data. The chloroplast genome spans 156,967 bp and consists of four main regions: the large single-copy (LSC) region (89,185 bp), the small single-copy (SSC) region (19,146 bp), and a pair of inverted repeats (IRs) (24,318 bp). The overall GC content of the chloroplast genome is 36.19%, with specific values of 33.99%, 29.79%, and 42.76% for the LSC, SSC, and IR regions, respectively. A total of 128 genes were annotated in the chloroplast genome, including 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis revealed that B. glauca subsp. hupehana is closely related to Bauhinia racemose, indicating a sister taxon relationship between the two species. This study significantly contributes to the chloroplast genomic resource for Bauhinia, laying the groundwork for future phylogenetic investigations within the genus.

Garlic Bulb Decay and Soft Rot Caused by the Cross-Kingdom Pathogen Burkholderia gladioli.

In 2021, two gram-negative bacterial strains were isolated from garlic (Allium sativum) bulbs showing decay and soft rot symptoms in Central Iran. The bacterial strains were aggressively pathogenic on cactus, garlic, gladiolus, onion, potato, and saffron plants and induced soft rot symptoms on carrot, cucumber, potato, and radish discs. Furthermore, they were pathogenic on sporophores of cultivated and wild mushrooms. Phylogenetic analyses revealed that the bacterial strains belong to Burkholderia gladioli. Garlic bulb rot caused by B. gladioli has rarely been reported in the literature. Historically, B. gladioli strains had been assigned to four pathovars, namely, B. gladioli pv. alliicola, B. gladioli pv. gladioli, B. gladioli pv. agaricicola, and B. gladioli pv. cocovenenans, infecting onion, Gladiolus sp., and mushrooms and poisoning foods, respectively. Multilocus (i.e., 16S rRNA, atpD, gyrB, and lepA genes) sequence-based phylogenetic investigations including reference strains of B. gladioli pathovars showed that the two garlic strains belong to phylogenomic clade 2 of the species, which includes the pathotype strain of B. gladioli pv. alliicola. Although the garlic strains were phylogenetically closely related to the B. gladioli pv. alliicola reference strains, they possessed pathogenicity characteristics that overlapped with three of the four historical pathovars, including the ability to rot onion (pv. alliicola), gladiolus (pv. gladioli), and mushrooms (pv. agaricicola). Furthermore, the pathotype of each pathovar could infect the hosts of other pathovars, undermining the utility of the pathovar concept in this species. Overall, using phenotypic pathovar-oriented assays to classify B. gladioli strains should be replaced by phylogenetic or phylogenomic analysis.

Identification of new major histocompatibility complex-B Haplotypes in Bangladesh native chickens.

The major histocompatibility complex in chicken demonstrates a great range of variations within varities, breeds, populations and that can eventually influence their immuneresponses. The preset study was conducted to understand the major histocompatibility complex-B (MHC-B) variability in five major populations of Bangladesh native chicken: Aseel, Hilly, Junglefowl, Non-descript Deshi, and Naked Neck. These five major populations of Bangladesh native chicken were analyzed with a subset of 89 single nucleotide polymorphisms (SNPs) in the high-density MHC-B SNP panel and Kompetitive Allele-Specific polymerase chain reaction genotyping was applied. To explore haplotype diversity within these populations, the results were analyzed both manually and computationally using PHASE 2.1 program. The phylogenetic investigations were also performed using MrBayes program. A total of 136 unique haplotypes were identified within these five Bangladesh chicken populations, and only one was shared (between Hilly and Naked Neck). Phylogenetic analysis showed no distinct haplotype clustering among the five populations, although they were shared in distinct clades; notably, the first clade lacked Naked Neck haplotypes. The present study discovered a set of unique MHC-B haplotypes in Bangladesh chickens that could possibly cause varied immune reponses. However, further investigations are required to evaluate their relationships with global chicken populations.

Halomonas citrativorans sp. nov., Halomonas casei sp. nov. and Halomonas colorata sp. nov., isolated from French cheese rinds.

Eight Gram-stain-negative bacterial strains were isolated from cheese rinds sampled in France. On the basis of 16S rRNA gene sequence analysis, all isolates were assigned to the genus Halomonas. Phylogenetic investigations, including 16S rRNA gene studies, multilocus sequence analysis, reconstruction of a pan-genome phylogenetic tree with the concatenated core-genome content and average nucleotide identity (ANI) calculations, revealed that they constituted three novel and well-supported clusters. The closest relative species, determined using the whole-genome sequences of the strains, were Halomonas zhanjiangensis for two groups of cheese strains, sharing 82.4 and 93.1 % ANI, and another cluster sharing 92.2 % ANI with the Halomonas profundi type strain. The strains isolated herein differed from the previously described species by ANI values <95 % and several biochemical, enzymatic and colony characteristics. The results of phenotypic, phylogenetic and chemotaxonomic analyses indicated that the isolates belonged to three novel Halomonas species, for which the names Halomonas citrativorans sp. nov., Halomonas casei sp. nov. and Halomonas colorata sp. nov. are proposed, with isolates FME63T (=DSM 113315T=CIRM-BIA2430T=CIP 111880T=LMG 32013T), FME64T (=DSM 113316T=CIRM-BIA2431T=CIP 111877T=LMG 32015T) and FME66T (=DSM 113318T=CIRM-BIA2433T=CIP 111876T=LMG 32014T) as type strains, respectively.

The Mitochondrial Genomes of Siboglinum plumosum and Oligobrachia dogieli (Annelida: Siboglinidae) and Their Phylogenetic Analysis.

Frenulates are a group of sedentary Annelida within the family Siboglinidae that inhabit the ocean floor and present a unique challenge for comprehensive molecular and phylogenetic investigations. In this study, we focused on the frenulates, specifically assembling the mitochondrial genomes of Siboglinum plumosum and Oligobrachia dogieli. The phylogenetic reconstruction placed S. plumosum as a sister taxon to S. ekmani, and O. dogieli as a sister taxon to S. fiordicum, supporting the non-monophyletic nature of the genus Siboglinum. Overall, this study supports the phylogeny of the family Siboglinidae while highlighting the need for additional molecular data within frenulates.

Morphology, Phylogeny, and Evolution of the Rarely Known Genus Admetella McIntosh, 1885 (Annelida, Polynoidae) with Recognition of Four New Species from Western Pacific Seamounts

The polynoid genus Admetella constitutes a deep‐sea assemblage of polychaetes, notable for their large bodies adorned with antennal scales positioned dorsally to the bases of lateral antennae. Furthermore, the genus exhibits swimming proficiencies facilitated by elongated parapodia and flattened chaetae. Despite the frequent encounters with Admetella members during various deep‐sea explorations, a substantial gap in our comprehension of their diversity, phylogeny, and evolutionary trajectories still exists. Our thorough morphological and phylogenetic investigations of specimens obtained from three seamounts located in the tropical western Pacific have unveiled six species belonging to the genus Admetella, four of these being newly identified as Admetella multiseta sp. nov., A. levensteini sp. nov., A. nanhaiensis sp. nov., and A. undulata sp. nov. The other two species of Admetella remain unidentifiable at the species level due to the loss of crucial details. Our phylogenetic analysis, grounded on 13 mitochondrial protein‐coding genes and the inclusion of 12S, 16S, 18S, 28S rRNA, and ITS1–ITS2 genes, substantiates the monophyly of Admetella. Admetella is positioned at an intermediate node within the phylogenetic tree, situated between representative shallow‐water and deep‐sea subfamilies. The independent evolution of antennal scales within Admetella among polynoids constitutes a synapomorphy for this genus. Ancestral state reconstruction (ASR) analyses suggest that deep‐sea polynoids evolved from shallow‐water ancestors that possessed lateral antennae, which were subsequently lost in members inhabiting extreme marine environments, such as deep‐sea hydrothermal vents and anchialine caves. The analysis further implicates that swimming ability independently evolved at least four times within the Polynoidae family.