The complete mitochondrial genome of deep-sea ophiuroid (Echinodermata: Ophiuroidea) from the Shkolnik Guyot, a northwest Pacific seamount.

Ophiuroids are a diversified benthic taxon in the deep sea. Given their various dispersal strategies, they are considered an adequate group to assess genetic connectivity, especially in the seamounts that function as islands. A.

Comparative genomics reveals the dynamic evolutionary history of cement protein genes of barnacles from intertidal to deep-sea hydrothermal vents.

Thoracican barnacles are a diverse group of marine organisms for which the availability of genome assemblies is currently limited. In this study, we sequenced the genomes of two neolepadoid species (Ashinkailepas kermadecensis, Imbricaverruca yamaguchii) from hydrothermal vents, in addition to two intertidal species. Genome sizes ranged from 481 to 1054 Mb, with repetitive sequence contents of 21.

Carbonate compensation depth drives abyssal biogeography in the northeast Pacific.

Abyssal seafloor communities cover more than 60% of Earth's surface. Despite their great size, abyssal plains extend across modest environmental gradients compared to other marine ecosystems. However, little is known about the patterns and processes regulating biodiversity or potentially delimiting biogeographical boundaries at regional scales in the abyss.

Phylogeny and shell form evolution of the hydrothermal vent asymmetrical barnacles (Cirripedia, Thoracicalcarea, Neoverrucidae).

Imbricaverruca and Neoverruca are two genera of hydrothermal vent asymmetrical barnacles in Neoverrucidae, but found in vents of the Southwest Pacific and Northwest Pacific Oceans, respectively. Imbricaverruca has a flattened operculum and the shell base with multiple whorls of imbricating plates, while Neoverruca has an inclined operculum and the shell base with fewer developed imbricating plates. It has been hypothesized that Imbricaverruca has apomorphic shell characters in Neoverrucidae.

Diversity and characterization of bacterial communities of five co-occurring species at a hydrothermal vent on the Tonga Arc.

Host-symbiont relationships in hydrothermal vent ecosystems, supported by chemoautotrophic bacteria as primary producers, have been extensively studied. However, the process by which densely populated co-occurring invertebrate hosts form symbiotic relationships with bacterial symbionts remains unclear. Here, we analyzed gill-associated symbiotic bacteria (gill symbionts) of five co-occurring hosts, three mollusks ("" , .

The mitochondrial genome of hydrothermal vent barnacle (Cirripedia: Thoracica) from the Indian Ocean.

Balanomorph species are hydrothermal vent endemic barnacles. In the genus , three species are known to date and they distribute at three different vent fields in Pacific and Indian Oceans, in the Southwest Pacific Ocean, in the East Pacific Ocean, and in the Indian Ocean. Therefore, species are considered to be a meaningful model taxon to elucidate the evolutionary history of vent organism in relation to geotectonic events.

A new species of hydrothermal vent stalked barnacle Vulcanolepas (Scalpelliforms: Eolepadidae) from the North Fiji Basin, Southwestern Pacific Ocean.

A new species of eolepadid stalked barnacle, Vulcanolepas fijiensis sp. nov., was collected from a hydrothermal vent in the North Fiji Basin, Southwestern Pacific Ocean, at a depth of 1988 m.

Complete mitochondrial genome of the hydrothermal vent shrimp (Decapoda: Caridea: Alvinocarididae) from the North Fiji basin.

The family Alvinocarididae is the monophyletic taxon which lives restrictively at chemosynthesis-based environments in the deep-sea. Here, for the first time, we report the complete mitogenome of the alvinocaridid vent shrimp from the North Fiji Basin. The mitogenome was 15,909 bp in length, with 65.

Complete mitochondrial genome of the hydrothermal vent stalked barnacle (Cirripedia, Scalpelliforms, Eolepadidae).

The family Eolepadidae is the only stalked barnacle in hydrothermal vent regions. Here, we determined the mitogenome of the eolepadid . The mitogenome was 17,374 bp long, with 76.

Population genetic differentiation of the hydrothermal vent crab Austinograea alayseae (Crustacea: Bythograeidae) in the Southwest Pacific Ocean.

To understand the origin, migration, and distribution of organisms across disjunct deep-sea vent habitats, previous studies have documented the population genetic structures of widely distributed fauna, such as gastropods, bivalves, barnacles, and squat lobsters. However, a limited number of investigations has been conducted in the Southwest Pacific Ocean, and many questions remain. In this study, we determined the population structure of the bythograeid crab Austinograea alayseae from three adjacent vent systems (Manus Basin, North Fiji Basin, and Tonga Arc) in the Southwest Pacific Ocean using the sequences of two mitochondrial genes (COI and 16S rDNA) and one nuclear gene (28S rDNA).

Complete mitochondrial genome of the hydrothermal vent barnacle (Cirripedia, Thoracica).

Thoracican barnacles are common in hydrothermal vent fields. Here, we characterized the first mitogenome of a hydrothermal vent barnacle. The mitogenome of was 15,585 bp in length and had the typical pancrustacean gene arrangement.

Complete mitochondrial genome of the deep-sea asymmetrical barnacle (Cirripedia, Thoracica, Verrucumorpha).

The hitherto suborder Verrucomorpha contains asymmetrical barnacles of two groups: the true Verrucomorpha ( + Verrucidae) and the Neoverrucidae. Here, we determined the mitochondrial genome (mitogenome) of , a true Verrucomorpha species. The mitogenome was 15,976 base pairs in length and had the typical pancrustacean gene arrangement.

Complete mitochondrial genome of the blind vent crab Gandalfus puia (Crustacea: Bythograeidae) from the Tonga Arc.

The brachyuran crab Gandalfus puia is a species endemic to the hydrothermal vent fields in the Tonga-Kermadec Arc. In order to understand G. puia at the genomic level, we sequenced its mitochondrial genome (mitogenome) and then compared to other bythograeids.

Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean.

We provide the mercury (Hg) and monomethylmercury (MMHg) levels of the plume water, sulfide ore, sediment, and mollusks located at the hydrothermal vent fields of the southern Tonga Arc, where active volcanism and intense seismic activity occur frequently. Our objectives were: (1) to address the potential release of Hg from hydrothermal fluids and (2) to examine the distribution of Hg and MMHg levels in hydrothermal mollusks (mussels and snails) harboring chemotrophic bacteria. While high concentrations of Hg in the sediment and Hg, As, and Sb in the sulfide ore indicates that their source is likely hydrothermal fluids, the MMHg concentration in the sediment was orders of magnitude lower than the Hg (<0.

Morphological, Molecular, and Biochemical Characterization of Monounsaturated Fatty Acids-Rich Chlamydomonas sp. KIOST-1 Isolated from Korea.

Microalgae hold promise as producers of sustainable biomass for the production of biofuels and other biomaterials. However, the selection of strains with efficient and robust production of desirable resources remains challenging. In this study, we isolated a green microalga from Korea and analyzed its morphological, molecular, and biochemical characteristics.

Morphological, molecular, and biochemical characterization of astaxanthin-producing green microalga Haematococcus sp. KORDI03 (Haematococcaceae, Chlorophyta) isolated from Korea.

A unicellular red microalga was isolated from environmental freshwater in Korea, and its morphological, molecular, and biochemical properties were characterized. Morphological analysis revealed that the isolate was a unicellular biflagellated green microalga that formed a non-motile, thick-walled palmelloid or red aplanospore. To determine the taxonomical position of the isolate, its 18S rRNA and rbcL genes were sequenced and phylogenetic analysis was performed.

Complete mitochondrial genome of the hydrothermal vent ghost shrimp Paraglypturus tonganus (Crustacea, Axiidea, Callianassidae).

Ghost shrimps are burrowing decapods that serve as bioturbators and habitat providers in seafloor environments. The hydrothermal vent ghost shrimp, Paraglypturus tonganus, was collected from a hydrothermal vent in the Tonga Arc. This species has a mitochondrial genome (mitogenome) of 15,924 bp in length with an AT content of 66.

Mitochondrial genome of the hydrothermal vent shrimp Nautilocaris saintlaurentae (Crustacea: Caridea: Alvinocarididae).

We determined the mitochondrial genome (mitogenome) of Nautilocaris saintlaurentae, sampled at vent fields of the Tofua Arc in the southwestern Pacific. The genome was 15,928 bp in length and had the typical mitogenome structure of the infraorder Caridea. Its protein-coding genes were very similar to other alvinocaridid species in respect to length, AT content, and start and stop codons.

Mitochondrial genome of the hydrothermal vent crab Austinograea alayseae (Crustacea: Bythograeidae): genetic differences between individuals from Tofua Arc and Manus Basin.

The brachyuran crab Austinograea alayseae is one of the most common species found in hydrothermal vent fields of the southwestern Pacific Ocean. In this study, we found that the mitochondrial genome (mitogenome) of A. alayseae from Tofua Arc is 15,611 bp in length and has the typical gene arrangement of a brachyuran.

Nuclear mitochondrial pseudogenes in Austinograea alayseae hydrothermal vent crabs (Crustacea: Bythograeidae): effects on DNA barcoding.

Members of the brachyuran crab family, Bythograeidae, are among the most abundant and common crabs in vent fields. However, their identification based on morphological characteristics often leads to incorrect species recognition due to a lack of taxonomic factors and the existence of sibling (or cryptic) species. For these reasons, we used DNA barcoding for vent crabs using mitochondrial cytochrome c oxidase subunit 1 (CO1).