Based upon COI‐5P, LSU rDNA, and rbcL sequence data and morphological characteristics, six new members of the noncalcified crustose genus of red algae Ethelia are described in a new family, ...Etheliaceae (Gigartinales), sister to the recently described Ptilocladiopsidaceae. The novel species are described from subtropical to tropical Atlantic and Indo‐Pacific Ocean basins; E. mucronata sp. nov. and E. denizotii sp. nov. from southern and northern Western Australia respectively, E. wilcei sp. nov. from the Cocos (Keeling) Islands of Australia, E. suluensis sp. nov. from the Philippines, E. umbricola sp. nov. from Bermuda and E. kraftii sp. nov. from Lord Howe Island, Australia. The generitype, Ethelia biradiata, originally reported from the Seychelles, Indian Ocean, is added to the Western Australian flora.
Using sequences of 5′ region of the cytochrome oxidase subunit 1 gene, large subunit rDNA, and ribulose‐1,5‐bisphosphate carboxylase/oxygenase large subunit gene as genetic markers to elucidate their ...phylogenetic positions, six unknown species from Western Australia, Tasmania, Lord Howe Is., and Norfolk Is. cluster with Meredithia in the Kallymeniaceae (Gigartinales), and are described as new members of this previously monospecific genus. Specimens from Bermuda referable to Kallymenia limminghei Mont. in the 20th century also clustered with this genetic grouping, not with the generitype of Kallymenia. The Bermudian specimens are further shown to be morphologically distinct from the type of K. limminghei (Guadeloupe, Caribbean Sea) and are described as a new species, Meredithia crenata. Using these Indo‐Pacific and Bermudian collections, our analyses further show that Psaromenia is closely related to Meredithia, and that Cirrulicarpus nanus sensu stricto should be returned to Meredithia.
Cryptonemia specimens collected in Bermuda over the past two decades were analysed using gene sequences encoding the large subunit of the nuclear ribosomal DNA and the large subunit of RuBisCO as ...genetic markers to elucidate their phylogenetic positions. They were additionally subjected to morphological assessment and compared with historical collections from the islands. Six species are presently found in the flora including C. bermudensis comb. nov., based on Halymenia bermudensis, and the following five new species: C. abyssalis, C. antricola, C. atrocostalis, C. lacunicola and C. perparva. Of the eight species known in the western Atlantic flora prior to this study, none is found in Bermuda. Specimens reported in the islands in the 1900s attributed to C. crenulata and C. luxurians are representative of the new species, C. antricola and C. atrocostalis, respectively.
The phylum Acidobacteria was created in 1997 in order to accommodate a large number of 16S rRNA gene sequences retrieved from various environments in cultivation-independent studies. At present, 26 ...major sequence clades or subdivisions (SDs) are recognized within this phylum, but only seven of them (SDs 1, 3, 4, 6, 8, 10 and 23) are commonly addressed as containing taxonomically described representatives. Here, we examined the currently explored diversity within the Acidobacteria using the candidate taxonomic unit circumscription system. Based on this analysis, 26 subdivisions were assigned to 15 class-level units, five of which contain described members. These include three earlier established classes Acidobacteriia, Blastocatellia and Holophagae, as well as two as-yet-undescribed groups defined by SDs 6 and 23, which we propose to name Vicinamibacteria classis nov. and Thermoanaerobaculia classis nov., respectively. The former assignment of Thermotomaculum hydrothermale to SD10 was found to be incorrect. This bacterium, therefore, was placed in the family Thermotomaculaceae fam. nov., order Thermotomaculales ord. nov. within the class Holophagae. We also propose establishing a number of high-level taxa to accommodate described representatives of SDs 3, 4, 6 and 23. The family Bryobacteraceae of SD3 Acidobacteria is placed in the order Bryobacterales ord. nov. within the taxonomic range of the class Acidobacteriia. The order Vicinamibacteriales ord. nov. is proposed to accommodate the family Vicinamibacteriaceae of SD6 Acidobacteria. Finally, the family Thermoanaerobaculaceae fam. nov., the order Thermoanaerobaculales ord. nov. are proposed to accommodate the only described representative of SD23, Thermoanaerobaculum aquaticum.
Since the description of the genus
in 1991, a total of 27 species have been described, although some species have shown 16S rRNA similarities below 95%, which is the cut-off that usually separates ...species that belong to different genera. The objective of the present study was to reassess the taxonomy of the genus
using information derived from the core genome (286 genes), a Multilocus Sequence Analysis (MLSA) with 13 housekeeping genes, as well as different genomic indexes like Average Nucleotide Identity (ANI),
DNA-DNA hybridization (
DDH), Average Amino-acid Identity (AAI), Percentage of Conserved Proteins (POCPs), and Relative Synonymous Codon Usage (RSCU). The study included a total of 39 strains that represent all the 27 species included in the genus
together with 13 strains that are potentially new species, and the analysis of 57 genomes. The different phylogenetic analyses showed that the
species grouped into four clusters. In addition,
and the candidatus species '
' appeared, as did
, the type species of the genus, in separate branches. Furthermore, the genomic indices ANI and
DDH not only confirmed that all the species were well-defined, but also the coherence of the clusters. The AAI and POCP values showed intra-cluster ranges above the respective cut-off values of 60% and 50% described for species belonging to the same genus. Phenotypic analysis showed that certain test combinations could allow the differentiation of the four clusters and the three orphan species established by the phylogenetic and genomic analyses. The origin of the strains showed that each of the clusters embraced species recovered from a common or related environment. The results obtained enable the division of the current genus
in at least seven different genera, for which the names
,
gen. nov.,
gen. nov.,
gen. nov.,
gen. nov.,
gen. nov., and Candidate '
gen. nov. are proposed.
In paddy soil, bacteria from the family
Geobacteraceae
have been shown to strongly contribute to the biogeochemical cycle. However, no
Geobacteraceae
species with validly published names have been ...isolated from paddy soil. In this study, we isolated and characterized four novel ferric reducing bacteria in the family
Geobacteraceae
from the paddy soils of three different fields in Japan. The four strains, S43
T
, Red53
T
, S62
T
, and Red111
T
, were Gram-stain negative, strictly anaerobic, chemoheterotrophic, and motile with peritrichous flagella. Phylogenetic studies based on 16S rRNA gene sequences, five concatenated housekeeping genes (
fusA
,
rpoB
,
recA
,
nifD
, and
gyrB
) and 92 concatenated core genes revealed that the four strains belong to the family
Geobacteraceae
and are most closely related to
Geobacter bemidjiensis
Bem
T
(97.4–98.2%, 16S rRNA gene sequence similarities) and
Geobacter bremensis
Dfr1
T
(97.1–98.0%). Genomic analysis with average nucleotide identity (ANI) and digital DNA–DNA hybridization (GGDC) calculations clearly distinguished the four isolated strains from other species of the family
Geobacteraceae
and indicated that strains S43
T
, Red53
T
, S62
T
, and Red111
T
represent independent species, with values below the thresholds for species delineation. Chemotaxonomic characteristics, including major fatty acid and whole cell protein profiles, showed differences among the isolates and their closest relatives, which were consistent with the results of DNA fingerprints and physiological characterization. Additionally, each of the four isolates shared a low 16S rRNA gene sequence similarity (92.4%) and average amino acid identity (AAI) with the type strain of the type species
Geobacter metallireducens
. Overall, strains S43
T
, Red53
T
, S62
T
, and Red111
T
represent four novel species, which we propose to classify in a novel genus of the family
Geobacteraceae
, and the names
Geomonas oryzae
gen. nov., sp. nov. (type strain S43
T
),
Geomonas edaphica
sp. nov. (type strain Red53
T
),
Geomonas ferrireducens
sp. nov. (type strain S62
T
), and
Geomonas terrae
sp. nov. (type strain Red111
T
) are proposed. Based on phylogenetic and genomic analyses, we also propose the reclassification of
Geobacter bremensis
as
Geomonas bremensis
comb. nov.,
Geobacter pelophilus
as
Geomonas pelophila
comb. nov., and
Geobacter bemidjiensis
as
Geomonas bemidjiensis
comb. nov.
Species descriptions of reptiles historically have relied exclusively on the use of morphological data; however, these external, phenotypic data do not always co-vary with lineage divergence. ...Consequently, it has become increasingly clear that species diversity has been underestimated in many evolutionary radiations. With the use of an integrative approach, we examined the genetic and morphological diversity present in a nearly endemic Philippine radiation of Eutropis. Results demonstrated that current taxonomy does not reflect evolutionary history and that in many cases, morphological divergence has become decoupled from genetic divergence. As a consequence, species diversity is significantly underestimated. Here, we rectify the major taxonomic problems present in Philippine Eutropis by providing formal descriptions for eight new species. Three of the four new species in the E. multicarinata species complex are sympatric with (and have long been confused with) previously described subspecies (which we also elevate to full species here). The fourth species is endemic to the Caroline Islands, clearly derived from a long-distance dispersal event from the Philippines. The new species in the E. indeprensa species complex are allopatrically or parapatrically distributed across the archipelago. In contrast to the last review of Philippine Eutropis, which suggested the endemic radiation was composed of five species (one of which was composed of two subspecies), we demonstrate that this group includes at least 14 distinct evolutionary lineages, with potential for additional diversity to be discovered pending further study.
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