Exceptional longevity in Okinawa: Demographic trends since 1975.

Demographers have studied the Japanese mortality pattern since Japan became the most longevous population worldwide, half a century ago. Nutrition and lifestyle were considered by epidemiologists, gerontologists and other scientists as the most important reasons explaining the Japanese superiority. In Okinawa, the mortality pattern is even more exceptional, but few demographers have pointed out this exception. Other scientists proposed different explanations - for example some genetic characteristics, less salt and more animal protein in the food, a mild climate, a higher level of activity, a better consideration of the oldest in the population and, globally speaking, a more traditional lifestyle. At the end of the 1980s, lower improvements of mortality among young adults were identified in Okinawa. In 2002, Okinawa fell from the 4th to the 26th place in the ranking of the 47 Japanese prefectures by male life expectancy. This has been considered by the population of Okinawa as a 'shock'. Our in-depth analysis of available life tables and associated mortality rates proves that the population of Okinawa is divided into two groups of generations: those born before World War II and those born after. The older generations clearly experience a highly favourable mortality pattern, whereas the younger generations show mortality levels that are definitively higher compared to mainland Japan. This contribution considers which factors may explain such a situation, including the plausible invalidation of the age of some oldest in the population. We plea for in-depth demographic age validation that will enhance all scientific findings so far and boost the exceptional longevity in Okinawa.

Divergent ecological responses to typhoon disturbance revealed via landscape-scale acoustic monitoring.

Climate change is increasing the frequency, intensity, and duration of extreme weather events across the globe. Understanding the capacity for ecological communities to withstand and recover from such events is critical. Typhoons are extreme weather events that are expected to broadly homogenize ecological dynamics through structural damage to vegetation and longer-term effects of salinization. Given their unpredictable nature, monitoring ecological responses to typhoons is challenging, particularly for mobile animals such as birds. Here, we report spatially variable ecological responses to typhoons across terrestrial landscapes. Using a high temporal resolution passive acoustic monitoring network across 24 sites on the subtropical island of Okinawa, Japan, we found that typhoons elicit divergent ecological responses among Okinawa's diverse terrestrial habitats, as indicated by increased spatial variability of biological sound production (biophony) and individual species detections. This suggests that soniferous communities are capable of a diversity of different responses to typhoons. That is, spatial insurance effects among local ecological communities provide resilience to typhoons at the landscape scale. Even though site-level typhoon impacts on soundscapes and bird detections were not particularly strong, monitoring at scale with high temporal resolution across a broad spatial extent nevertheless enabled detection of spatial heterogeneity in typhoon responses. Further, species-level responses mirrored those of acoustic indices, underscoring the utility of such indices for revealing insight into fundamental questions concerning disturbance and stability. Our findings demonstrate the significant potential of landscape-scale acoustic sensor networks to capture the understudied ecological impacts of unpredictable extreme weather events.

Methylomarinovum tepidoasis sp. nov., a moderately thermophilic methanotroph of the family Methylothermaceae isolated from a deep-sea hydrothermal field.

A novel aerobic methanotrophic bacterium, designated as strain IN45T, was isolated from in situ colonisation systems deployed at the Iheya North deep-sea hydrothermal field in the mid-Okinawa Trough. IN45T was a moderately thermophilic obligate methanotroph that grew only on methane or methanol at temperatures between 25 and 56 °C (optimum 45-50 °C). It was an oval-shaped, Gram-reaction-negative, motile bacterium with a single polar flagellum and an intracytoplasmic membrane system. It required 1.5-4.0 % (w/v) NaCl (optimum 2-3 %) for growth. The major phospholipid fatty acids were C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8. The 16S rRNA gene sequence comparison revealed 99.1 % sequence identity with Methylomarinovum caldicuralii IT-9T, the only species of the genus Methylomarinovum with a validly published name within the family Methylothermaceae. The complete genome sequence of IN45T consisted of a 2.42-Mbp chromosome (DNA G+C content, 64.1 mol%) and a 20.5-kbp plasmid. The genome encodes genes for particulate methane monooxygenase and two types of methanol dehydrogenase (mxaFI and xoxF). Genes involved in the ribulose monophosphate pathway for carbon assimilation are encoded, but the transaldolase gene was not found. The genome indicated that IN45T performs partial denitrification of nitrate to N2O, and its occurrence was indirectly confirmed by N2O production in cultures grown with nitrate. Genomic relatedness indices between the complete genome sequences of IN45T and M. caldicuralii IT-9T, such as digital DNA-DNA hybridisation (51.2 %), average nucleotide identity (92.94 %) and average amino acid identity (93.21 %), indicated that these two methanotrophs should be separated at the species level. On the basis of these results, strain IN45T represents a novel species, for which we propose the name Methylomarinovum tepidoasis sp. nov. with IN45T (=JCM 35101T =DSM 113422T) as the type strain.

Universal occurrence of organophosphate tri-esters and di-esters in marine sediments: Evidence from the Okinawa Trough in the East China Sea.

Despite numerous data on organophosphate tri-esters (tri-OPEs) in the environment, literatures on organophosphate di-esters (di-OPEs) in field environment, especially marine sediments remain scarce. This study addresses this gap by analyzing 35 abyssal sediment samples from the middle Okinawa Trough in the East China Sea. A total of 25 tri-OPEs and 10 di-OPEs were determined, but 13 tri-OPEs and 2 di-OPEs were nondetectable in any of these sediment samples. The concentrations of ∑12tri-OPE and ∑8di-OPE were 0.108-32.2 ng/g (median 1.11 ng/g) and 0.548-15.0 ng/g (median 2.74 ng/g). Chlorinated (Cl) tri-OPEs were the dominant tri-esters, accounting for 47.5 % of total tri-OPEs on average, whereas chlorinated di-OPEs represented only 19.2 % of total di-OPEs. This discrepancy between the relatively higher percentage of Cl-tri-OPEs and lower abundance of Cl-di-OPEs may be ascribed to the stronger environmental persistence of chlorinated tri-OPEs. Source assessment suggested that di-OPEs were primarily originated from the degradation of tri-OPEs rather than industrial production. Long range waterborne transport facilitated by oceanic currents was an important input pathway for OPEs in sediments from the Okinawa Trough. These findings enhance the understanding of the sources and transport of OPEs in marine sediments, particularly in the Okinawa Trough.

Is Japan at low risk for PFAS immunotoxicity?: human biomonitoring study in contaminated areas in Japan.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are now considered global contaminants posing health risks. Recent human biomonitoring data in Japan are presented. METHODS: Human biomonitoring data from Japan, dating back to 2000, were reviewed. In addition, 399 serum samples collected in a primary care clinic in Urayasu City, Okinawa Island-one of the highest PFAS-exposed areas in Japan-between 2021 and 2022 were analyzed. Serum levels of four PFAS were compared with risk levels based on the assessment by Sonne et al. and the European Food Safety Agency. RESULTS: The PFAS levels in the general population from various areas other than Hokkaido (16.1-43.5 ng/mL) are classified at moderate to severe risk for immunotoxicity based on the assessment. CONCLUSIONS: A portion of the Japanese population has had high exposure to PFAS and was at high risk of immunotoxicity, and this situation remained in PFAS-contaminated areas in the 2020s.

An environmental DNA metabarcoding survey reveals generic-level occurrence of scleractinian corals at reef slopes of Okinawa Island.

Coral reefs have the highest biodiversity of all marine ecosystems in tropical and subtropical oceans. However, scleractinian corals, keystone organisms of reef productivity, are facing a crisis due to climate change and anthropogenic activities. A broad survey of reef-building corals is essential for worldwide reef preservation. To this end, direct observations made by coral-specialist divers might be supported by another robust method. We improved a recently devised environmental DNA (eDNA) metabarcoding method to identify more than 43 scleractinian genera by sampling 2 l of surface seawater above reefs. Together with direct observations by divers, we assessed the utility of eDNA at 63 locations spanning approximately 250 km near Okinawa Island. Slopes of these islands are populated by diverse coral genera, whereas shallow 'moats' sustain fewer and less varied coral taxa. Major genera recorded by divers included Acropora, Pocillopora, Porites and Montipora, the presence of which was confirmed by eDNA analyses. In addition, eDNA identified more genera than direct observations and documented the presence of previously unrecorded species. This scleractinian coral-specific eDNA method promises to be a powerful tool to survey coral reefs broadly, deeply and robustly.

Stakelama marina sp. nov., isolated from seawater of the Tangyin hydrothermal field in the Okinawa Trough.

A Gram-stain-negative, strictly aerobic, rod-shaped and non-flagellated marine bacterium, designated strain LXI357T, was isolated from deep-sea water sampled at the Tangyin hydrothermal field in the Okinawa Trough. The growth temperature range was 20-45 °C (optimum, 28 °C). Strain LXI357T was also able to grow at pH 5.0-7.5 (optimum, pH 6.0-7.0) and in the presence of 0.5-11 % (optimum, 7%, w/v) NaCl. Strain LXI357T was oxidase-negative and catalase-positive. The predominant fatty acids were C18 : 1 ω7c and C16 : 0. The major polar lipids of strain LXI357T contained phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phospholipid, sphingoglycolipid, diphosphatidylglycero and an unidentified aminolipid. Based on the results of 16S rRNA gene sequence analysis, strain LXI357T belonged to the genus Stakelama and was most closely related to Stakelama flava CBK3Z-3T (96.28%, 16S rRNA gene sequence similarity), followed by Stakelama algicida Yeonmyeong 1-13T (95.67%), Stakelama pacifica JLT832T (95.46%) and Sphingosinicella vermicomposti YC7378T (95.43%). Genome relatedness between strain LXI357T and Stakelama flava CBK3Z-3T was computed using average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity, with values of 76.02, 20.9 and 71.1 %, respectively. The genomic DNA G+C content of strain LXI357T is 64.1 mol%. In addition, strain LXI357T has multiple genes related to sulphur metabolism, including genes encoding for the Sox system. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished strain LXI357T from its closest phylogenetic neighbours. According to the results of polyphasic analyses, strain LXI357T is considered to represent a novel species of the genus Stakelama, for which the name Stakelama marina sp. nov. is proposed. The type strain is LXI357T (=MCCC 1K06076T=KCTC 82726T).

Risk Factors of Preterm Birth in Okinawa Prefecture, the Southernmost Island Prefecture of Japan.

OBJECTIVES: A high rate of preterm birth has been reported in Okinawa Prefecture, the southernmost island prefecture of Japan. Hence, this study aimed to identify the risk factors for preterm birth in this prefecture. METHODS: This retrospective study included data from January 2013 to December 2019 from three facilities in Okinawa Prefecture. Of 13,468 cases of preterm birth at ≥ 22 weeks of gestation, 11,868 were included in this study. Stillbirth and multiparity cases were excluded. First, we compared the overall preterm and full-term birth groups by categorizing the patient background, obstetric, and fetal risk factors. Further, we categorized preterm births into three groups (22-27, 28-33, and 34-36 weeks of gestation) and examined patient background factors to identify potential risk factors for the occurrence of preterm birth in each group. RESULTS: Preterm births accounted for 21.2% (2,521 cases) of all cases, with the rates of 2.6% (317 cases), 6.7% (800 cases), and 11.8% (1,404 cases) at 22-27, 28-33, and 34-36 weeks of gestation, respectively. To prevent preterm birth in Okinawa Prefecture, the present study specifically focused on patient background characteristics. In the multinomial logistic regression, the risk factors for preterm birth at 22-27 weeks of gestation were previous preterm birth (P < 0.0001) and lower age (P = 0.026); at 28-33 weeks of gestation, the risk factors were previous preterm birth (P < 0.0001) and history of cervical conization (P = 0.009); and at 34-36 weeks of gestation, only previous preterm birth (P < 0.0001) was a risk factor. CONCLUSIONS FOR PRACTICE: Previous preterm birth, younger age, and history of cervical conization were risk factors for Preterm birth in Okinawa. To reduce premature births in Okinawa Prefecture, it is important to pick up women with these risk factors and provide them with appropriate guidance and education on an ongoing basis.

Nitrosophilus kaiyonis sp. nov., a hydrogen-, sulfur- and thiosulfate-oxidizing chemolithoautotroph within "Campylobacteria" isolated from a deep-sea hydrothermal vent in the Mid-Okinawa Trough.

A novel bacterium, strain MOT50T, was isolated from the chimney structure at the Iheya North field in the Mid-Okinawa Trough. The cells were motile short rods with a single polar flagellum. Growth was observed between 40 and 65 â„ƒ (optimum, 52 â„ƒ), at pH values between 5.0 and 7.1 (optimum, pH 6.1) and in the presence of 2.0-4.0% NaCl (optimum, 2.5%). The isolates utilized molecular hydrogen, thiosulfate, or elemental sulfur as the sole electron donor. Thiosulfate, elemental sulfur, nitrate, and molecular oxygen are utilized as the sole electron acceptor. Ammonium is required as a nitrogen source. Thiosulfate, elemental sulfur, sulfate, or sulfite serves as a sulfur source for growth. The G + C content of the genomic DNA was 28.9%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain MOT50T belonged to the genus Nitrosophilus of the class "Campylobacteria", and its closest relative was Nitrosophilus labii HRV44T (97.20%). On the basis of the phylogenetic, physiological, and molecular characteristics, it is proposed that the organism represents a novel species within the genus Nitrosophilus, Nitrosophilus kaiyonis sp. nov. The type strain is MOT50T (= JCM 39187T = KCTC 25251T).

The First Bopyrid Isopod from Hydrothermal Vents: Pleurocryptella shinkai sp. nov. (Isopoda: Epicaridea) Parasitizing Shinkaia crosnieri (Decapoda: Anomura).

Deep-sea hydrothermal vents are 'extreme' environments harboring diverse animal communities, powered by chemosynthesis. Though vent-endemic macrofauna have been a center of interest since their discovery in 1977, macroparasites have received little attention. Here, we report a bopyrid epicaridean isopod infesting the symbiotic munidopsid squat lobster Shinkaia crosnieri Baba and Williams, 1998 from three vent fields of Okinawa Trough, and describe it as Pleurocryptella shinkai sp. nov. Although morphologically close to the congeners Pleurocryptella formosa Bonnier, 1900, Pleurocryptella wolffi Bourdon, 1972, and Pleurocryptella altalis Williams, Boyko, and Marin, 2020, both females (via body proportion and characters of barbula, antennae, pleopods, and pleomeres) and males (via features of the head, pleomeres, and uropods) of the new species exhibit distinctive characters. Phylogenetic reconstruction based on the 18S rRNA gene (850 bp) was insufficiently resolved to clarify the relationship of different epicaridean lineages or the exact position of P. shinkai sp. nov., but it recovered P. shinkai sp. nov. in a distant position from the type genus of Pseudioninae, indicating non-monophyly of this subfamily. Crustaceans are successful in vents but this is only the second vent epicaridean reported, after Thermaloniscus cotylophorus Bourdon, 1983 from the East Pacific Rise described from a single cryptoniscus larva. As such, this is the first report of a vent bopyrid isopod and the first vent epicaridean with a known host. Some epicaridean lineages have adapted to tolerating the conditions of hydrothermal vents, and future research will likely uncover more epicarideans and other interesting parasites from these extreme habitats.

Uncollected Bones and Ambiguous Loss: Okinawan Mourning Rituals in the Northern Mariana Islands.

The study expounds upon the psychological concept of 'ambiguous loss,' proposed by Pauline Boss. The article attempts to broaden the concept's individualistic focus by offering a more ethnographically nuanced and socioculturally contextualized application of the concept. It examines how Okinawan WWII survivors, who repatriated from the Northern Mariana Islands after the war, relied on their belief system to make sense of 'abnormal' deaths during war, and the lack of proper mortuary rituals usually conducted for 'normal' deaths. The article argues that religio-spiritual rituals during their pilgrimages to the Marianas were the means with which those struggling with ambiguous loss attempt to deal with their psychological trauma and spiritual pain. It is also argued, however, that the uncollected bodies/bones continue to haunt the bereaved families, so their struggle with the loss cannot come to a complete 'closure,' resulting in their repeated visits to the sites of their loved ones' violent deaths.

Development and characterization of microsatellite markers in the small Indian mongoose (Urva auropunctata).

BACKGROUND: The small Indian mongoose (Urva auropunctata) is one of the world's worst invasive alien species and eradication programs are ongoing worldwide. The development of individual and sex identification markers will improve their management. METHODS AND RESULTS: We searched for novel mongoose microsatellite markers using genome-wide screening and identified 115,265 tetra-nucleotide repeat loci. Of 96 loci tested, 17 were genotyped in 28 mongooses from the Okinawa population. The genetic diversity analysis showed that the average expected and observed heterozygosity and number of alleles were 0.55, 0.56, and 2.94, respectively. Of 17 loci, one deviated from Hardy-Weinberg equilibrium and six loci pairs were likely linked to each other. However, we succeed in identifying all individuals using all of the microsatellite loci. The novel sex identification markers worked successfully in a test using sex known samples. CONCLUSION: Our novel microsatellite and sex identification markers should be useful in studies of individual identification and population genetics of the mongoose.

Ovarian Development and Larval Release of the Hermit Crab Clibanarius eurysternus (Hilgendorf, 1879) (Decapoda: Anomura: Diogenidae) in Okinawa, Japan.

This study investigated ovarian development and larval release in the hermit crab Clibanarius eurysternus, which inhabits the upper intertidal zone on Okinawa, Japan. Adult females were collected monthly and had a high gonadosomatic index (GSI) from May to October. Oocytes at vitellogenic stages were observed from May to October. Some females had post-ovulatory follicles in the ovary and embryos on the abdomen (ovigerous females) in June and August, suggesting active ovarian development and larval release during these months (breeding season). When adult females were collected weekly according to the lunar cycle, a high GSI with oocytes at the tertiary yolk globule stage in the ovaries was maintained in all lunar phases. Since post-ovulated follicles were seen in ovaries collected around the last quarter and new moons, darkness at night is needed for spawning. Ovigerous females exposed to stepwise changes in hydrostatic pressure exhibited significantly higher synchrony between larval release and high pressure at night from the last quarter moon to the new moon, suggesting the importance of the tidal amplitude cycle in larval release under non-moonlight conditions. We concluded that the continuity of synchronous spawning and larval release of C. eurysternus are repeated under darkness and high tide at night during the breeding season.

Distribution and Genetic Divergence of Deep-Sea Hydrothermal Vent Copepods (Dirivultidae: Siphonostomatoida: Copepoda) in the Northwestern Pacific.

Copepods in the family Dirivultidae are one of the most successful meiofauna in deep-sea hydrothermal vent fields and are abundant near venting fluid. Although vents are spatially limited ocean habitats, they are distributed widely in the Atlantic, Pacific, and Indian Oceans. However, knowledge of dirivultid biogeography and phylogeography remains limited, especially in the northwestern Pacific. Here, we obtained partial mitochondrial COI gene sequences of three dirivultids from the northwestern Pacific-Stygiopontius senokuchiae and an unidentified Chasmatopontius species from vent fields in the Izu-Bonin Arc and Stygiopontius senckenbergi associated with the squat lobster Shinkaia crosnieri in the Okinawa Trough-and analyzed them in comparison with existing data. The among-species sequence diversity exceeded 80 out of 560 bp (14% or 0.166 in Kimura 2-parameter distance), whereas the within-species diversity was less than 10 bp (2% or 0.018 in Kimura 2-parameter distance), with no genetic saturation. Each species formed a monophyletic clade and the genetic region targeted is deemed reliable for identifying species and populations for these copepods. Among the three genera targeted, only Chasmatopontius formed a monophyletic cluster, while Aphotopontius and Stygiopontius did not. Species delimitation analyses suggested the existence of cryptic species in Chasmatopontius. Subdivision among local populations was observed in Aphotopontius, but not in Stygiopontius in the same distribution, implying potential differences in dispersal ability among different genera of dirivultids. Further sampling is required, to fill the spatial gaps to elucidate the biogeography and evolution of dirivultids in the global deep ocean.

Effects of Ingesting Fucoidan Derived from Cladosiphon okamuranus Tokida on Human NK Cells: A Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Pilot Study.

The aim of this study was to evaluate the effects of ingesting fucoidan derived from Okinawa mozuku (Cladosiphon okamuranus) on natural killer (NK) cell activity and to assess its safety in healthy adults via a randomized, double-blind, parallel-group, placebo-controlled pilot study. Subjects were randomly divided into two groups-a placebo group (ingesting citric acid, sucralose, and caramel beverages; n = 20; 45.5 ± 7.8 years (mean ± standard deviation)) and a fucoidan group (3.0 g/day from beverages; n = 20; 47.0 ± 7.6 years); after 12 weeks, blood, biochemical, and immunological tests were performed. Clinically adverse events were not observed in any of the tests during the study period. In addition, adverse events due to the test food were not observed. In the immunological tests, NK cell activity was significantly enhanced at 8 weeks in the fucoidan group, compared to before ingestion (0 weeks). In addition, a significantly enhanced NK cell activity was observed in male subjects at 8 weeks, compared with the placebo group. These results confirm that Okinawa mozuku-derived fucoidan enhances NK cell activity and suggest that it is a safe food material.

Surveillance of urachal abscess in the Kyushu-Okinawa area of Japan.

OBJECTIVE: To report a multicenter experience with the management of urachal abscess treatment in Japan. METHODS: This was a retrospective study of 263 cases of urachal abscess managed at 12 university hospitals in the Kyushu-Okinawa region over a 10-year period. Age, sex, abscess size, clinical symptoms, type of urachal remnants, and treatment were collected and analyzed. RESULTS: The average age was 29.8 ± 18.1 years, with males accounting for approximately two-thirds of the study population. The average abscess size was 1.7 cm (range 0-11 cm). The most common presenting symptom was umbilical secretion (66%), followed by abdominal pain (46%). A total of 127 patients (48.3%) were treated with antibiotics alone, whereas 136 patients (51.7%) received surgical treatment. The surgical approach was laparotomy in 75 patients (61.0%) and laparoscopic surgery in 48 patients (39.0%). Regarding the type of urachal remnant, the urachus sinus (180 patients) accounted for 68.4% of the total. CONCLUSIONS: To our knowledge, this study represents the first report on urachal abscess treatment in Japan. Our data show that the clinical symptoms might vary depending on the type of urachus remnant. It should be noted that gross hematuria, a characteristic symptom of urachal cancer, is rare in patients with urachal abscess.

Reproductive traits of the dwarf gobies Pandaka trimaculata and Pandaka lidwilli in the western Pacific Ocean: histological evidence from one of the smallest fishes in the world.

Gobies are generally small fishes which play important roles in estuarine ecosystems, yet little attention has been paid to their life-history traits in the western Pacific region. In the present study, the reproductive traits of the dwarf gobies Pandaka trimaculata and Pandaka lidwilli were explored by examining their populations in a subtropical estuary on Okinawa-jima Island, Japan, over 15 months. The Okinawan populations of both species shared similar reproductive traits. Pandaka trimaculata and P. lidwilli exhibited early female maturation at minimum sizes of 8.8 and 9.4 mm standard length (SL), respectively, which indicate that populations of the Pandaka species in the subtropical region represent some of the smallest fishes in the world. Nonetheless, they also had high relative body sizes at maturity relative to the attained asymptotic SLs, ranging from 75.8% to 80.4%, which suggests that their populations are vulnerable to negative impacts. Both the species also had prolonged spawning periods, extending from February to November (P. trimaculata) and from January to October (P. lidwilli), indicating that these local populations have a high potential for maintenance and resilience. Their spawning periods, sizes at maturity and fecundities varied among seasons and latitudes, possibly because of low water temperatures affecting the relative allocation of energy to growth and reproduction. Such plasticity of life-history traits in these small fishes indicates that they would be suitable models for understanding the evolution of life-history strategies and monitoring the responses of organisms to climate change.

Ancylomarina longa sp. nov., isolated from southern Okinawa Trough sediment and emended description of the family Marinifilaceae.

A Gram-stain-negative, obligately anaerobic, non-motile, non-spore-forming, long-rod-shaped and non-flagellated bacterial strain, designated T3-2 S1-CT, was isolated from a sediment sample collected at the Okinawa Trough. Phylogenetic analyses of 16S rRNA gene sequences and the whole genome revealed that strain T3-2 S1-CT was a member of the family Marinifilaceae and exhibited less than 95.1 % sequence similarities to the closely related type strains of the family Marinifilaceae. Optimal growth occurred at pH 7.0, 28 °C and in the presence of 3 % (w/v) NaCl. The isoprenoid quinone of strain T3-2 S1-CT was identified as menaquinone-7 (MK-7) and the predominant fatty acids (>10 %) were iso-C15 : 0 (38.9 %) and anteiso-C15 : 0 (11.6 %). The major polar lipids were one phosphatidylethanolamine, one phosphatidylmonomethylethanolamine, one aminolipids, two unidentified lipids and two unidentified phospholipids. The DNA G+C content of strain T3-2 S1-CT was 35.7 mol%. On the basis of the results of polyphasic analyses, strain T3-2 S1-CT is considered to represent a novel species of the genus Ancylomarina, for which the name Ancylomarina longa sp. nov. is proposed. The type strain is T3-2 S1-CT (=KCTC 15505T=MCCC 1K01617T).

Gramella bathymodioli sp. nov., isolated from a mussel inhabiting a hydrothermal field in the Okinawa Trough.

A Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and non-flagellated marine bacterium strain, designated BOM4T, was isolated from a mussel inhabiting the Tangyin hydrothermal field of the Okinawa Trough. The growth temperature was in the range of 16-40 °C, and the optimum temperature was 37 °C. Optimal growth occurred at pH 7.0 and in the presence of 1 % (w/v) NaCl. The predominant isoprenoid quinone of strain BOM4T was identified as menaquinone-6 (MK-6). The predominant fatty acids (>10 %) were iso-C15 : 0(43.8 %) and iso-C17 : 0 3-OH (17.5 %). The major polar lipids comprised one phosphatidylethanolamine, three unidentified aminolipids and two unidentified lipids. Based on 16S rRNA gene sequence analyses, strain BOM4T was found to be most closely related to Gramella aestuarii JCM 17790T (96.7 %), followed by Gramella flava JLT2011T (96.1 %), Gramella sediminilitoris GHTF-27T (95.6 %) and Gramella gaetbulicola RA5-111T (95.5 %) and with lower sequence similarities (93.7- 95.4 %) to other species of the genus Gramella. Genome relatedness between strain BOM4T and G. aestuarii JCM 17790T was computed using both average nucleotide identity and DNA-DNA hybridization with values of 75.6 and 19.3±2.4 %, respectively. The DNA G+C content of strain BOM4T was 41.4 mol%. On the basis of polyphasic analysis, strain BOM4T was considered to represent a novel species of the genus Gramella, for which the name Gramella bathymodioli sp. nov. is proposed. The type strain is BOM4T (=MCCC 1K03735T=JCM 33424T).

Carideicomes alvinocaridis gen. nov., sp. nov., a marine bacterium isolated from shrimp gill in a hydrothermal field of Okinawa Trough.

A Gram-stain-negative, strictly aerobic, oval-shaped, non-motile bacterium with no flagella, designated strain SCR17T, was isolated from a shrimp gill habitat in Tangyin hydrothermal field of Okinawa Trough. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SCR17T formed a lineage within the family 'Rhodobacteraceae', and shared 16S rRNA gene sequence similarity of 93.2-96.2 % to the related genera Aquicoccus and Roseivivax. Strain SCR17T was able to grow with 0-14 % (w/v) NaCl (optimum, 9-10 %). The sole respiratory quinone was ubiquinone-10. The major polar lipids of strain SCR17T comprised phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), an unidentified aminolipid (AL), an unidentified phospholipid (PL) and an unidentified lipid (L). The predominant fatty acids (more than 10 % of the total fatty acids) were C18 : 1ω7c or/and C18 : 1ω6c, anteiso-C15 : 0, C16 : 0 and C19 : 0 cyclo ω8c . The genomic DNA G+C content of strain SCR17T was 67.7 mol%. Based on polyphasic taxonomic analyses, strain SCR17T is considered to represent a novel species in a new genus of the family 'Rhodobacteraceae', for which the name Carideicomes alvinocaridis gen. nov., sp. nov. is proposed. The type strain of Carideicomes alvinocaridis is SCR17T (=JCM 33426T=MCCC 1K03732T). The discovery of a novel host-associated bacterium in hydrothermal fields provides an opportunity for the study of host-bacterial symbiosis in extreme environments.