High Degree Of Endemism Research Articles

Pleurotomariida (Gastropoda) from the upper Anisian platform carbonates of the Dolomites (Southern Alps, Italy): systematics, palaeobiogeography and Triassic recovery

Pleurotomariida (Gastropoda) from the upper Anisian platform carbonates of the Dolomites (Southern Alps, Italy): systematics, palaeobiogeography and Triassic recovery

中国野生报春花属物种多样性与地理分布数据集

Catalogue of Life serves as the background baseline information for the biota of a given natural geographic region or administrative unit. The timely updating of its dynamics is an important basis for the research, management and monitoring of biodiversity conservation. The integration and sharing of biodiversity data can provide a scientific basis for the development of related studies. Primula L. is a typical genus characterized by a broad distribution and a high degree of endemism, with diverse habitats and a complex taxon structure. An in-depth analysis of its geographical distribution pattern and characteristics can provide a foundational basis for the conservation and use of germplasm resources. With the aim of offering a reference for germplasm resource surveys and application research on seed introduction, and based on a large amount of basic data and literature, this paper adopts the taxonomic system used by Flora of China to update the list of wild species of the genus Primula L. distributed in the terrestrial area of China. In the paper, we counted their species diversity, composition and other information, and established a dataset of the diversity and geographical distributions of wild Primula L. in China. This genus predominantly thrives in the temperate and subtropical zones of the Northern Hemisphere. Its diversity center and modern distribution center are also widely distributed in the eastern Himalayas and Hengduan Mountains in broad sense, Tianshan Mountain Area, Qinba Mountain area, Wuling Mountains Area, Qinghai Tibet Plateau, Yunnan Guizhou Plateau and other high-altitude areas. Additionally, it extends to middle and lower altitude areas with prominent karst and Danxia landscapes. As of October 2022, a total of 397 species (28 varieties and 26 subspecies) of the genus Primula L. have been recorded in China, including 296 endemic species (including subspecies classification units, the same below) in China. In addition to the five administrative regions of Jiangsu, Hainan, Shanghai, Hong Kong and Macao, the distribution of wild primroses has been recorded in various provincial administrative regions in China, with Sichuan Province boasting the highest species richness and endemism at the provincial scale (177 species), followed by Yunnan Province (176 species) and the Tibet Autonomous Region (171 species). At the county scale, Shangri-La City ranks first in species richness with 62 species.

Allied species with Dicksonia sellowiana Hook. in a High Montane Araucaria Forest Remnant, in Southern Brazil

The Araucaria Forest in highlands is an environment characteristic of regions with altitudes greater than 1200 above sea level, in southern Brazil. The species that occur in this place are adapted to conditions of low temperatures and high humidity, where the presence of Dicksonia sellowiana Hook., a tree-sized pteridophyte with expressive importance value in many remnants. This research aimed to identify the associations of this species in a remnant of Araucaria Forest in the mountain region of Santa Catarina. The site was inventoried with permanent plots of fixed area of 200 m², which were systematically and contiguously distributed in 3 transects following the slope gradient of the terrain (1411 to 1940 m). The surveys evaluated the scientific name, geographic coordinates and DBH, with an inclusion limit of 5 cm for each individual. Subsequently, 14 individuals of D. sellowiana were randomly selected and used as a reference to the center of the sampling units of Prodan method, than the six closest trees were measured, identified and measured the distance from the center of the unit sampling to the sixth tree (R6) to determine its area. As the measurements of the permanent plots contain the geographic coordinates of all trees, the selection of Prodan sampling units and the collection of data (R6, N.ha-1, G.ha-1) were performed using ArcGis Software. The average basal area value was 69.5 m².ha-1 and the average density was 1628 ind.ha-1, values compatible with those obtained in the permanent plots (69.4 m².ha-1 and 1630 ind.ha-1 respectively), obtaining sample sufficiency by the collector curve. Dicksonia sellowiana showed association with 14 species, being inserted in characteristic environments with less sun exposure, slopes and presence of watercourses, generating an environment with low floristic diversity, however, with a high degree of endemism in the Atlantic Forest.

A glimpse into the dark – the bacterial and archaeal diversity of tropical anchialine cave sediments

Using ion torrent sequencing of the V4 region of the 16S rRNA gene, we investigated the sediment from four anchialine caves on Eleuthera (Bahamas). Anchialine caves are secluded, landlocked marine ecosystems, with high degrees of endemism. In the cave sediments, the bacterial and archaeal communities differ from marine communities and between caves, while often resembling those from low oxygen or anaerobic marine sediments. The waters of all caves investigated here were mostly saline and oxygenated, with Windermere Abyss differing from the other caves. This was mirrored by the bacterial and archaeal communities, with members of the wb1-A12 clade, Nitrosopumilaceae , members of the NB1-j phylum, and Actinomarinales being dominant in Preacher’s Blue Hole, Valentine’s Cave, and Bung Hole while Desulfatiglans , Bathyarchaeia, and members of the GIF3 and Sva0485 clades were dominant in Windermere Abyss. All communities showed taxa found in oxygenated and anoxic sediments, thus indicating a variety of chemoautotrophic lifestyles, including methane-, nitrogen- and sulphur cycling. The communities were different from other caves and included understudied or otherwise rare taxa, partially from deep sea sediments, implying that the isolation might be an evolutionary factor, and indicating that anchialine caves could be a window into the deep sea.

Local stochastics and ecoclimatic situation shape phytophagous chafer assemblage composition.

Very little is known about factors determining the assemblage structure of megadiverse polyphagous-herbivore scarab chafers in the tropics (Coleoptera: Scarabaeidae). Here, we examined the composition of Sri Lankan chafer assemblages and investigated whether it is influenced more by the general ecoclimatic situation, macrohabitat, or indetermined stochastic biotic and abiotic factors of each locality. We also explored the influence of the latter on separate lineages and general body size. Based on dedicated field surveys conducted during the dry and wet seasons, we examined 4847 chafer individuals of 105 species sampled using multiple UV-light traps in 11 localities covering different forest types and altitudinal zones. Assemblages were assessed for compositional similarity, species diversity, and abundance within four major eco-spatial partitions: forest types, elevational zones, localities, and macrohabitats. Our results revealed that assemblages were shaped mainly by locality stochastics (i.e., multi-factor ensemble of all biotic and abiotic environmental conditions at local scale), and to a minor extent by ecoclimatic conditions. Macrohabitat had little effect on the assemblage composition. This was true for the entire chafer assemblage as well as for all single lineages or different body size classes. However, in medium and large species the contrasts between localities were less pronounced, which was not the case for individual lineages of the assemblage. Contrasts of assemblage similarity between localities were much more evident than those for forest types and elevation zones. Significant correlation between species composition and geographic distance was found only for the assemblage of small-bodied specimens. Seasonal change (dry-wet) in species composition was minor and only measurable in a few localities. The strong turnover between examined localities corroborates with the high degree of endemism in many phytophagous chafers, particularly in Sericini. Connected with their hypothetic poor habitat specificity and polyphagy, this might also explain why so many chafer crop pests in the Asian tropics are endemics.

Chilean bee diversity: Contrasting patterns of species and phylogenetic turnover along a large‐scale ecological gradient

AbstractChile's isolation and varied climates have driven the evolution of a unique biodiversity with a high degree of endemism. As a result, Chile encompasses diverse environments, including the Mediterranean‐type ecosystem, a global biodiversity hotspot. These environments are currently threatened by anthropogenic land use change impacting the integrity of local biomes and associated species. This area is the most intensively sampled in the country with high endemicity of native bee species. Characterizing habitat requirements of bees is a pressing priority to safeguard these insects and the ecosystem services they provide. We investigated broadscale patterns of bee (Hymenoptera: Apoidea: Anthophila) diversity using newly accessible expert‐validated datasets comprising digitized specimen records from Chilean and US collections, and novel expert‐validated‐type specimen data for the bees of Chile. We used a generalized dissimilarity modeling (GDM) approach to explore both compositional and phylogenetic β‐diversity patterns across latitudinal, altitudinal, climate, and habitat gradients in well‐sampled bee assemblages in Central Chile. Using the GDM measures of increasing compositional and environmental dissimilarity, we categorized and compared the most important drivers of these patterns and used them to classify “wild bee ecoregions” (WBEs) representing unique assemblages. Turnover of bee assemblages was explained primarily by latitudinal variation (proxy for climate) from south to north in Chile. However, temperature variations, precipitation, and the presence of bare soil also significantly explained turnover in bee assemblages. In comparison, we observed less turnover in phylogenetic biodiversity corresponding to spatial gradients. We identified six de novo ecoregions (WBEs), all with distinct taxa, endemic lineages, and representative species. The WBEs represent distinct spatial classifications but have similarities to existing biogeographical classifications, ecosystems, and bioclimatic zones. This approach establishes the baseline needed to prioritize bee species conservation efforts across this global biodiversity hotspot. We discuss the novelty of this classification considering previous biogeographical characterizations and their relevance in assessing conservation priorities for bee conservation. We argue that Chile's WBEs highlight areas in need of funding for bee species surveys and description, distribution mapping, and strengthening of conservation policies.

Species Delimitation, Phylogenomics, and Biogeography of Sulawesi Flying Lizards: A Diversification History Complicated by Ancient Hybridization, Cryptic Species, and Arrested Speciation.

The biota of Sulawesi is noted for its high degree of endemism and for its substantial levels of in situ biological diversification. While the island's long period of isolation and dynamic tectonic history have been implicated as drivers of regional diversification, this has rarely been tested in the context of an explicit geological framework. Here we provide a tectonically-informed biogeographical framework that we use to explore the diversification history of Sulawesi flying lizards (the Draco lineatus Group), a radiation that is endemic to Sulawesi and its surrounding islands. We employ a framework for inferring cryptic speciation that involves phylogeographic and genetic clustering analyses as a means of identifying potential species followed by population demographic assessment of divergence-timing and rates of bi-directional migration as means of confirming lineage independence (and thus species status). Using this approach, phylogenetic and population genetic analyses of mitochondrial sequence data obtained for 613 samples, a 50-SNP data set for 370 samples, and a 1249-locus exon-capture data set for 106 samples indicate that the current taxonomy substantially understates the true number of Sulawesi Draco species, that both cryptic and arrested speciation have taken place, and that ancient hybridization confounds phylogenetic analyses that do not explicitly account for reticulation. The Draco lineatus Group appears to comprise 15 species - nine on Sulawesi proper and six on peripheral islands. The common ancestor of this group colonized Sulawesi ~11 Ma when proto-Sulawesi was likely composed of two ancestral islands, and began to radiate ~6 Ma as new islands formed and were colonized via overwater dispersal. The enlargement and amalgamation of many of these proto-islands into modern Sulawesi, especially during the past 3 Ma, set in motion dynamic species interactions as once-isolated lineages came into secondary contact, some of which resulted in lineage merger, and others surviving to the present.

Two new species of monitor lizards (Squamata: Varanus) endemic to the Louisiade and Tanimbar Archipelagos with a key to the subgenus Euprepiosaurus

ABSTRACT We describe two new species of Varanus, one each endemic to the Louisiade and Tanimbar Archipelagos in Papua New Guinea and Indonesia, respectively. The new species belong to the subgenus Euprepiosaurus and, therein, to the widely distributed and relatively species-rich Varanus indicus group. They can be distinguished from all other recognised species by scalation, colour-pattern and genetic differences. The new species from Tanimbar is most closely related to V. indicus and V. melinus, from which it can be distinguished by its dark blue/grey tongue and higher middorsal and midventral scale counts. The new species from the Louisiades can be distinguished from its phylogenetically and geographically nearest relative, V. chlorostigma, by the presence of dorsal crossbands, the mostly pink tongue mottled with grey, and higher midbody scale count. The Louisiades constitute the easternmost archipelago of Milne Bay Province in eastern Papua New Guinea, and they host a diverse herpetofauna with a high degree of endemism; Varanus louisiadensis sp. nov. increases the known number of herpetofaunal endemics in that archipelago to 60. The Tanimbar Islands are situated in the southern part of Maluku Province (Moluccas), Indonesia, and are a minor centre of vertebrate endemism; Varanus tanimbar sp. nov. increases the number of known herpetofaunal endemics there to six. http://www.zoobank.org/urn:lsid:zoobank.org:pub:E06BDE2A-0B24-4CB5-B46E-6B93476CC3EB

Patterns of Richness and Endemism in the Gypsicolous Flora of Mexico

Gypsum soils occur around the world, mainly in arid regions. These harsh environments promote unusual flora with high degrees of endemism. Mexico has extensive gypsum outcrops, but their flora has been poorly studied. However, the highest species richness and endemism are expected to be concentrated in Mexico’s northern dry regions. To promote the study of this flora and its conservation, we estimate how well sampled it is, quantify species richness, identify centers of endemism, and detect which gypsum outcrops lie within federal protected natural areas (PNA). We conducted exhaustive literature and herbaria reviews to generate a database of botanical records on gypsum soils. The total species and gypsophyte richness were calculated using cell grids. Centers of endemism were identified using the corrected weighted endemism index (CWE). We mapped the gypsum outcrops within PNA polygons. The most collected sites are Cuatro Ciénegas (Coahuila) and Santo Domingo Tonalá (Oaxaca), which also had the highest total species richness. Nevertheless, gypsophyte richness was higher in Cuatro Ciénegas and Nuevo León. The CWE identified seven gypsophyte centers of endemism. Mexico hosts the most diverse gypsophile flora in the world, despite having been only partially studied and collected. The regions with the highest species richness and endemism are unprotected.

Large sampling effort is not related to richness and geographic distribution of Cladocera (Crustacea, Branchiopoda) in the Brazilian Savannah

ABSTRACT The Cerrado is home of the headwaters of some important Brazilian basins. Such biome has a high diversity of animal and plant species with a high degree of endemism. This premise is well documented for microcrustaceans of the Superorder Cladocera, although many areas still need sampling. In this context, the objective of the present investigation was to evaluate the geographic distribution and richness of Cladocera in the Cerrado biome. The analyzed data were obtained from the authors database on Brazilian Cladocera and distributed according to the hydrographic regions comprised in the biome. Species distribution models were used to determine the areas with the highest probability of occurrence of Cladocera. We analyzed 125 publications, resulting in 2829 records. In total, we obtained 161 taxa, belonging to 48 genera and seven families. Regarding the Hydrographic Regions, Paraná presented the highest richness, followed by TocantinsAraguaia and São Francisco. Our result indicates that most studies are concentrated in certain areas. Furthermore, the species distribution models indicated that transition areas between biomes have the highest probability of occurrence of genera and families. Our results indicate significant gaps in the knowledge, making it necessary to expand inventories and ecological studies in areas still unsampled.

Effects of Amazonian flying rivers on frog biodiversity and populations in the Atlantic rainforest.

Given the speed at which humans are changing the climate, species with high degrees of endemism may not have time to avoid extinction through adaptation. We investigated through teleconnection analysis the origin of rainfall that determines the phylogenetic diversity of rainforest frogs and the effects of microclimate differences in shaping the morphological traits of isolated populations (which contribute to greater phylogenetic diversity and speciation). We also investigated through teleconnection analysis how deforestation in Amazonia can affect ecosystem services that are fundamental to maintaining the climate of the Atlantic rainforest biodiversity hotspot. Seasonal winds known as flying rivers carry water vapor from Amazonia to the Atlantic Forest, and the breaking of this ecosystem service could lead Atlantic Forest species to population decline and extinction in the short term. Our results suggest that the selection of morphological traits that shape Atlantic Forest frog diversity and their population dynamics are influenced by the Amazonian flying rivers. Our results also suggest that the increases of temperature anomalies in the Atlantic Ocean due to global warming and in the Amazon forest due to deforestation are already breaking this cycle and threaten the biodiversity of the Atlantic Forest hotspot.

Recent Data on the Distribution of Freshwater Ichthyofauna in Albania

Abstract In this article, we provide an updated list of freshwater fishes in Albania for each sub-basin. The distribution data and taxa-lists presented are based on a literature review up to October 2022 and intensive fieldwork conducted in the last 15 years. Distributional records of 101 fish species (deriving from 25 families) in 11 different sub-basins are reported. There are new records that include native, alien and translocated fish species. The distinctiveness of Albanian freshwater fishes is highlighted while defining a specific ichthyological region for the whole Balkan region. The freshwater fish fauna of Albania represents a special value of the national heritage, especially due to its diversity and a high degree of endemicity. This is mainly due to the complex geological and climatic conditions, and the location between the Adriatic and Ionian Seas on the west and the continental areas of the Balkans on the other side, which have allowed different colonization from outside the area and long periods of speciation. Eleven hydrographic basin units are analyzed for species composition, evolutionary patterns, and ecological features. This review brings the number of Albanian freshwater fish taxa to 101, with 20 species added from the previous 1995 inventory and several species deleted due to taxonomic changes.

First detailed description of follicle development in a chimaeroid, the American elephant fish Callorhinchus callorhynchus

Chimaerods represent an enigmatic lineage of cartilaginous fishes and the least studied group within Chondrichthyans. They have a widespread global distribution with a high degree of endemism. In addition, this group has been considered among the least threatened species of Chondrichthyans, but also the most data-deficient group, with biological information lacking for most species. This study represents the first microanatomical, histological, and ultrastructural description of the different stages of folliculogenesis in Callorhinchus callorhynchus, and the first ultrastructural study about this topic within chimaeroids. Specimens of different maturity stages were collected from landings of the commercial fleet operating in San Matías Gulf, Argentina. Folliculogenesis shows some differences compared to other elasmobranchs. Oogonia were present in immature and mature females. Atretic follicles of different sizes were present in mature female ovaries. There is a significant difference between the macroscopic (∼10 mm) and microscopic (∼ 2 mm) follicular size at the beginning of vitellogenesis. There is no evidence of an epigonal organ. The results are discussed in a physiological and reproductive context. This study provides valuable information that will contribute to the understanding of the reproductive biology of the chimaeroids species and its potential for fishery exploitation recovery.

Current State of Knowledge of Páramo Amphibians in Colombia: Spatio Temporal Trends and Information Gaps to Be Strengthened for Effective Conservation

Background and Research Aims: Globally, Colombia is the country with the largest extent of Páramos (delimited in 36 complexes) and with the greatest number of amphibian species in this ecosystem. This work consolidated scientific literature on the amphibians of the Colombian Páramos to characterize temporal, taxonomic, thematic, and geographic patterns, which allow us to identify information gaps that must be fulfilled to achieve effective species conservation. Methods: We conducted a systematic literature survey with seven different search strategies and generated a database. We read each document's Abstract, Methods, Study Area, Results, and supplementary material, following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) protocol. Results: We found 405 documents published between 1863 and 2021. The composition and richness of 142 amphibian species (95 endemics to Colombia), presented significant differences in Páramo complexes and between sectors. Since 2000, the diversity of research topics has increased with a high proportion of studies on Natural History, Systematics and Taxonomy, and Conservation, distributed between 19 and 22 of the departments with Páramos in their jurisdiction. However, much of this knowledge concentrates in less than 20% of total species in just 6% of Páramos complexes. Conclusion: We found critical shortfalls in taxonomy, spatial information, and conservation actions on Páramos amphibians. We need to increase studies that include field data in more geographic areas and research topics, such as Population and Community ecology, Natural history (from a quantitative approach), Infectious disease, and Ecophysiology. Implications for Conservation: The scientific information gaps represent a challenge in generating effective strategies to conserve Páramo amphibians, considering the high degree of endemism and threats to these species. More than 80% of the Páramo amphibian species only have the information of their descriptions and little is known about their ecological requirements, population size, or data related to specific threats.

A perspective from the past in conservation of plant biodiversity in central China

Biodiversity has increasingly come under threat from human activity everywhere on Earth. China, with over 33,000 species of vascular plants, is a megadiverse region, in part because of its diversity in topography and climates. One of its most extensive biomes is broadleaved evergreen/warm mixed forest which dominates eastern Asia and Central China. There is some debate about how glacial/interglacial cycles across the Quaternary had an impact on this biome. There were certainly broad scale changes in distribution of many key species. Here, we examine the four palaeoecological records from Central China that contain both LGM and Mid-Holocene vegetation records and consider the degree of biodiversity in Central China with the aim of developing a broad overview of the history on plants in the region. It is clear that in the mountainous regions of Central China, many taxa survived the LGM in situ, showing that there was enough stable habitat to support key species. Some mountainous areas have high degrees of endemism which suggests that fragmentation of populations across glacial/interglacial cycles may have been an important component in favoring speciation. The consideration of past records and modern species distributions have significance in selecting conservation areas.

Whole-genome analyses disentangle reticulate evolution of primroses in a biodiversity hotspot.

Biodiversity hotspots, such as the Caucasus mountains, provide unprecedented opportunities for understanding the evolutionary processes that shape species diversity and richness. Therefore, we investigated the evolution of Primula sect. Primula, a clade with a high degree of endemism in the Caucasus. We performed phylogenetic and network analyses of whole-genome resequencing data from the entire nuclear genome, the entire chloroplast genome, and the entire heterostyly supergene. The different characteristics of the genomic partitions and the resulting phylogenetic incongruences enabled us to disentangle evolutionary histories resulting from tokogenetic vs cladogenetic processes. We provide the first phylogeny inferred from the heterostyly supergene that includes all species of Primula sect. Primula. Our results identified recurrent admixture at deep nodes between lineages in the Caucasus as the cause of non-monophyly in Primula. Biogeographic analyses support the 'out-of-the-Caucasus' hypothesis, emphasizing the importance of this hotspot as a cradle for biodiversity. Our findings provide novel insights into causal processes of phylogenetic discordance, demonstrating that genome-wide analyses from partitions with contrasting genetic characteristics and broad geographic sampling are crucial for disentangling the diversification of species-rich clades in biodiversity hotspots.

A checklist of social wasps (Vespidae: Polistinae) from Tocantins state, Brazil

Tocantins state has high biodiversity and a high degree of endemism, nevertheless, there are no studies on the diversity of social wasps. This study introduces a survey of social wasps actively collected using entomological nets and Malaise trap in addition to different light traps in sixteen sites in the Amazon and Cerrado biomes in Tocantins state, Brazil. We sampled a total of 1,013 social wasps distributed in 57 species of 13 genera. Fifty of these species and nine genera represent new distribution records for the state. Some species are not commonly found in collections and lists of species, and Protopolybia picteti (de Saussure, 1854) is newly recorded for Brazil. Such an increase of 714% may indicate that Polistinae richness is probably higher in the studied regions and that the state of Tocantins may well contain several additional (yet unrecorded) social wasp species. More comprehensive studies should be conducted to enhance the knowledge of wasp species in this state, contributing to our understanding of the biodiversity in Northern Brazil.

Catalogue of the millipedes (Myriapoda: Diplopoda) from Chile

A catalogue of the millipede species recorded or described from Chile is presented, both in continental and insular territories, including synonyms, type localities, and distribution maps, based on the published literature between 1847 and 2022. A total of six orders, eleven families, 26 genera, 75 species and two subspecies were found distributed almost all over the Chilean territory. Most of the records in Chile are concentrated in the central-south zone of the country; furthermore, the described species have a high degree of endemism and the existence of seven introduced species is recognized. A key for the identification of the orders, families, and genera of millipedes occurring in Chile are provided. Finally, the species Chondrodesmus auxus Chamberlin, 1957, Chondrodesmus sierricola Chamberlin, 1957 and Rhinocricus gaudichaudi (Gervais, 1847) are proposed in nomina dubia.

First report of the termite Glyptotermes ceylonicus (Blattodea: Isoptera: Kalotermitidae) from India: an example of discontinuous distribution

We report Glyptotermes ceylonicus (Holmgren, 1911), an endemic Sri Lankan termite, for the first time from India. Glyptotermes show a high degree of endemism throughout the world. Record of this species from the current location indicates a wide distribution of this species in southern India, in the past, before the complete separation of Sri Lanka from India. The current distribution of Glyptotermes ceylonicus is also an example of discontinuous distribution. Pictorial illustrations of the morphologically important parts and revised key for the Indian species are provided.

Comparative Analysis of the Mitochondrial Genome of Galatheanthemum sp. MT-2020 (Actiniaria Galatheanthemidae) From a Depth of 9,462 m at the Mariana Trench

The hadal zone, which represents the deepest marine habitat on Earth (6,000–11,000 m), is a harsh environment mainly characterized by extremely high hydrostatic pressure, and this habitat is believed to have a high degree of endemism. The deep-sea anemone family Galatheanthemidae comprises two valid species exclusively from the hadal; however, no other information about this family is currently available. In the present study, a sea anemone was collected from a depth of 9,462 m at the Mariana Trench and was defined as Galatheanthemum sp. MT-2020 (Actiniaria Galatheanthemidae). The mitochondrial genome of Galatheanthemum sp. MT-2020 was circular, was 16,633 bp in length, and contained two ribosomal RNA genes, 13 protein-coding genes and two transfer RNA genes. The order of the genes of Galatheanthemum sp. MT-2020 was identical to that of the majority of the species of the order Actiniaria. The value of the AT-skew was the lowest in the whole mitochondrial genome, with a positive GC skew value for the atp8 gene, while other species, except Antholoba achates, had the negative values of the GC skew. Galatheanthemum sp. MT-2020 was clustered with another abyssal species, Paraphelliactis xishaensis, in the phylogenetic tree, and these species diverged in the early Jurassic approximately 200 Mya from the shallow-sea species. The usage ratio of valine, which is one of the five amino acids with the strongest barophilic properties, in the mitochondrial genomes of the two abyssal species was significantly higher than that in other species with habitats above the depth of 3,000 m. The ω (dN/dS) ratio of the genomes was 2.45-fold higher than that of the shallow-sea species, indicating a slower evolutionary rate. Overall, the present study is the first to provide a complete mitogenome of sea anemones from the hadal and reveal some characteristics that may be associated with adaptation to an extreme environment.