Isolation of highly copper-resistant bacteria from deep-sea hydrothermal fields and description of a novel species Marinobacter metalliresistant sp. nov.

Introduction: Hydrothermal vents, rich in heavy metals, provided a unique niche for heavy metal resistant microbes. However, knowledge about copper resistant microbes in deep sea hydrothermal vents is still limited. Methods: The copper-resistant bacteria were isolated from deep-sea hydrothermal vent samples and conducted thorough physical, phylogenetic, and genomic analyses to elucidate their copper resistance capability and related genes. Results: Twelve highly copper-resistant bacteria (up to 6-10 mM) were isolated from deep sea hydrothermal fields They were affiliated with the Pseudoalteromonas (4), Marinobacter (3), Halomonas (2), Psychrobacter (1), and Pseudomonas (1) genus in the α-Proteobacteria, and the Sphingomonas (1) genus in the ß-Proteobacteria. The presence of copper in the medium obviously induced the amount of polysaccharides and proteins in the crude extracellular polymeric substances (EPS) produced by Halomonas sp. CuT 3-1, Pseudoalteromonas sp. CuT 4-3 and Marinobacter metalliresistant CuT 6, which could absorb 40 to 50 mg•g-1 copper. We further described a novel species, Marinobacter metalliresistant sp. nov. CuT 6T, which exhibited a higher copper resistance and encoded more heavy metal resistance-related genes than other Marinobacter species. Discussion: It revealed that the copper resistance capability exhibited by these strains in hydrothermal fields is likely attributed to the production of exopolymeric substances, such as polysaccharides and proteins, as well as active transport or efflux mechanisms for heavy metals.

Dynamics of subsurface chlorophyll maxima in the northern Indian Ocean.

Subsurface chlorophyll maxima (SCM) significantly contributes to oceanic primary productivity, emphasizing the need to study its dynamics and governing mechanisms. We used datasets from various platforms to investigate relationships between the SCM characteristics (SCM depth (ZSCM), SCM magnitude (Chlmax), SCM thickness (TSCM)) and environmental variables modulated by various physical processes in the Northern Indian Ocean (NIO). In the Arabian Sea (western NIO), seasonal processes like convective mixing and upwelling, primarily regulated the SCM characteristics. In the Bay of Bengal (eastern NIO), SCM characteristics were jointly influenced by fresh water influx, barrier layer formation, presence of eddies, and the propagation of Kelvin and Rossby waves. Any changes in these oceanic processes, potentially driven by climate change, could therefore impact oceanic primary production. Additionally, a positive association obtained between Chlmax and downward CO2 flux, while a shallower ZSCM, associated with higher concentrations of DMS, indicated SCM's role in regulating atmospheric gases.

Polychlorinated biphenyls in the surface and deep waters of the Southern Indian Ocean and Coastal Antarctica.

Polychlorinated biphenyl compounds (PCBs) are industrial chemicals whose production was discontinued in the early nineties in most countries. Sill, PCBs are detectable in pristine and remote locations. Occurrence in regions such as Southern Oceans and Antarctica are influenced by the global, and regional, cycling. Here, we studied the surface and deep ocean distribution of indicator- and dioxin-like PCB congeners in the Southern Indian Ocean (SIO), and the coast of Antarctica (COA) during the tenth Indian Southern Ocean Expedition (SOE-10), December 2017-February 2018. ∑21PCBs in SIO surface waters ranged from 3.8 to 167.1 pg L-1 (average ± standard deviation: 35.7 ± 48.4 pg L-1), and in COA from 1.0 to 41.8 pg L-1 (13.8 ± 12.7 pg L-1), respectively. A noticeable gradient was observed, with higher PCBs levels in northern latitudes than southern latitudes in the SIO, and higher levels in the eastern longitudes compared to western longitudes in the COA. Results suggest the influence of secondary sources, or re-emission, of PCBs in the Southern Oceans and Antarctica. Both regions showed notable PCB levels in surface and deep waters (up to 1000 m) due to ongoing surface sources and remineralization processes in deeper waters. Multimedia modeling with the global model (BETR-Global) suggests the SIO act as a net sink for PCBs in the ocean.

Rapid cycling and emission of volatile sulfur compounds in the eastern Indian Ocean: Impact of runoff inputs and implications for balancing atmospheric carbonyl sulfide budget.

Volatile sulfur compounds, such as dimethyl sulfide (DMS), carbonyl sulfide (OCS), and carbon disulfide (CS2), significantly influence atmospheric chemistry and climate change. Despite the oceans being an important source of these sulfides, the limited understanding of their biogeochemical cycles in seawater introduces considerable uncertainties in quantifying their oceanic emissions and assessing atmospheric OCS budgets. To address this issue, we conducted a comprehensive field survey in the tropical eastern Indian Ocean (EIO) to examine the spatial distributions, source-sink dynamics, and sea-air exchange fluxes of marine DMS, OCS, and CS2. Our study indicates that nutrients, organic matter, and freshwater input from terrestrial runoff significantly affect most of the source-sink processes of these sulfides in the Bay of Bengal and even the tropical EIO. The resulting sulfide accumulation in seawater combined with high wind speeds establishes the tropical EIO as a considerable direct and indirect atmospheric OCS source. These insights underscore the potentially critical role of marine environments influenced by runoff in contributing to the atmospheric OCS budget. However, by integrating these results with previous field surveys, we believe that actual OCS emissions from tropical oceans exceed some bottom-up box-model simulations, yet fall significantly below those predicted by top-down models, still insufficient to bridge the atmospheric OCS source gap. Our detailed examination of source-sink dynamics offers deeper insights into the marine sulfur cycle and has potential implications for refining future box-models, thus mitigating uncertainties in estimating marine sulfur emissions.

New carnivorous sponges (Porifera: Cladorhizidae) from Western Australia, collected by a Remotely Operated Vehicle (ROV).

The last two decades have reinvigorated systematic research on predatory sponges, mainly fuelled by advances in technology that have facilitated collection in deep-water habitats. This research presents six new species of carnivorous sponges from the family Cladorhizidae Dendy, 1922 from the western continental margin of Australia. The new species are Abyssocladia johnhooperi nov. sp., Abyssocladia aurora nov. sp., Abyssocladia janusi nov. sp., Axoniderma challengeri nov. sp., Cladorhiza vanessaekins nov. sp. and Nullarbora ningalooa nov. sp.. This material was collected by ROV during expeditions FK200308 to the Ningaloo Canyons expedition off the mid-west coast near Ningaloo, and FK200126 to the Southwest Australian canyons expedition, in Western Australia. These and other expeditions by the Schmidt Ocean Institute in 2020-21 formed a campaign around Australia's deep sea and mesophotic environments, which has vastly increased our understanding of biodiversity in these habitats.

Design and management considerations for the Kenya-Tanzania marine transboundary conservation area.

Although transboundary conservation areas (TCAs) are critical tools for protecting ecosystems and ecological processes that transcend national jurisdictions, they are challenging to create due to the differences in governance contexts and capacity and power dynamics among countries. Marine TCAs are also more difficult to enforce relative to terrestrial TCAs because most nations still treat oceans as open access. Current guidelines for TCA development and implementation also focus mostly on terrestrial TCAs, which are not practical for marine TCAs. Hence, we reviewed the challenges associated with the design and management of marine TCAs and devised analytical and practical approaches to support the application of spatial planning frameworks and adaptive governance mechanisms. We used the lessons from the review to examine the decisions made for the proposed marine TCA in the Kenya-Tanzania border region and created options and considerations to promote effective design and management processes. We found the obstacles to marine TCAs in general are related to issues of fit, particularly differences in environmental research capacity, socioeconomic contexts, and internal institutional arrangements. These included differences in knowledge and capacity for marine ecological research and conservation; ability to adjust and update data; differences in values, interests, and resource uses; conservation costs; jurisdictional differences; engagement of multiple levels of organization; and differences in legal bases and policy development processes. Understanding and reconciling these challenges during the TCA development process can help enhance meaningful discussions in the design of the TCA and cultivate the enabling conditions for collaborative governance across countries and within different levels of organization from national to local actors.

Consideraciones en el diseño y gestión del área marina de conservación transfronteriza en Kenia y Tanzania Resumen Aunque las áreas de conservación transfronterizas (ACT) son herramientas importantes para proteger los ecosistemas y los procesos ecológicos que trascienden la jurisdicción nacional, crearlas es un reto debido a la diferencia en los contextos de gobierno y la capacidad y las dinámicas de poder entre los países. Las ACT marinas también son más difíciles de ejecutar en relación a las terrestres porque la mayoría de los países todavía tratan al océano como de libre acceso. Los lineamientos actuales para el desarrollo e implementación de las ACT también se enfocan principalmente en las ACT terrestres, lo cual no es práctico para las ACT marinas. Por lo tanto, revisamos los retos asociados con el diseño y gestión de las ACT marinas y concebimos estrategias analíticas y prácticas para apoyar con la aplicación de los marcos de planeación espacial y los mecanismos de gobierno adaptativo. Usamos lo aprendido con la revisión para analizar las decisiones tomadas para la ACT marina propuesta en la región fronteriza de Kenia y Tanzania y creamos opciones y consideraciones para promover el diseño y procesos de manejo efectivos. Encontramos que los obstáculos para las ACT marinas en general se relacionan con temas de ajuste, en particular las diferencias en la capacidad de investigación ambiental, los contextos socioeconómicos y los acuerdos institucionales internos. Estos obstáculos incluyeron diferencias en el conocimiento y capacidad para la investigación ecológica marina; la habilidad para ajustar y actualizar datos; las diferencias en los valores, intereses y usos de los recursos; los costos de conservación; las diferencias jurídicas; la participación de varios niveles de organización; y las diferencias en las bases legales y los procesos de desarrollo de políticas. El entendimiento y reconciliación de estos retos durante el proceso de desarrollo de una ACT puede ayudar a mejorar las discusiones significativas en el diseño de la ACT y a cultivar las condiciones que permitan la gestión colaborativa entre los países y entre los diferentes niveles de organización, desde el nacional hasta los actores locales.

Diversity patterns and ecological assembly mechanisms of bacterial communities in the northeastern Indian Ocean epipelagic waters during the northeast monsoon.

Disentangling microbial community diversity patterns and assembly mechanisms is critical for understanding ecological processes and evaluating biogeochemical cycling in ecosystems. However, the diversity patterns and assembly mechanism of the microbial communities in the epipelagic waters in the northeastern Indian Ocean (NEIO) on the spatial scale are still unclear. In this study, we investigated the spatial dynamics, geographic distribution pattern, and assembly process of the bacterial community using 532 samples collected from the epipelagic waters in the NEIO during the northeast monsoon. The results indicate that the bacterial richness and Bray-Curtis dissimilarity exhibited the strongest correlations with depth compared to the latitudinal and longitudinal scales. The dissolved oxygen was identified as the most important environmental factor affecting the bacterial richness and Bray-Curtis dissimilarity compared to temperature and salinity. The distance-decay relationship (DDR) of the bacterial community strengthened with increasing water depth. Turnover was the predominant ß-diversity component influencing the spatial changes in the whole bacterial community. The dispersal limitation of the stochastic process and homogeneous selection of the deterministic process governed the bacterial ecological assembly process of the whole bacterial community. Abundant and rare subcommunities differed in terms of the niche breath, composition changes. The abundant subcommunities exhibited a much wider niche breath than the rare subcommunities. Regarding the abundant subcommunity species changes, the contributions of the turnover and nestedness varied with the water depth and oceanic region. In contrast, turnover was the major ß-diversity component regarding the changes in the rare species. These data improve our understanding of the ecological processes of bacterial community assemblages in the NEIO.

Biogeographic patterns and community assembly mechanisms of bacterial community in the upper seawater of seamounts and non-seamounts in the Eastern Indian Ocean.

Seamounts are widespread underwater topographic features in the ocean that exert an influential role in shaping the microbial biogeographic distribution. Nevertheless, research on the differences in microbial biogeographic distribution between seamount and non-seamount upper water column is still lacking, particularly in the Indian Ocean where studies are limited. In the present study, a total of 45 seawater samples were collected from the water column (5-200 m) of seamounts (HS) and non-seamounts (E87 transect) regions in the Eastern Indian Ocean (EIO) for the analysis of microbial biogeographic patterns and community assembly processes. The results indicated that bacterial community diversity did not differ significantly between the HS and E87 transect regions; however, the community composition was significantly different. Additionally, bacterial community diversity, composition, as well as structure were more affected by depth than by region. Community diversity tended to increase with depth in E87 transect region, while it tended to decrease in HS region. A distance decay analysis also demonstrated that bacterial communities were more influenced by environmental and depth distances than geographic distances. In the assembly of bacterial communities on HS and E87 transect regions, as well as at different depths, stochastic processes, particularly dispersal limitation, were found to be predominant. These findings enhance our comprehension of bacterial community characteristics in the upper seawater of seamounts and non-seamounts regions in the EIO and offer insights into the assembly processes shaping microbial communities at varying depths. IMPORTANCE: By comparing the bacterial diversity, composition, and structure in the upper seawater of seamount and non-seamount areas, we provide valuable insights into the influential role of seamounts in shaping microbial biogeography. The finding that the depth had a more significant impact on bacterial community characteristics than region underscores the importance of considering vertical stratification when examining microbial distributions. Moreover, the dominance of stochastic processes, particularly dispersal limitation, in governing community assembly across both seamount and non-seamount areas offers critical implications for the mechanisms underlying microbial biogeographic patterns in these dynamic ocean environments. This study expands the current knowledge and lays the groundwork for further investigations into the complex interactions between oceanographic features, environmental gradients, and microbial community dynamics in the Indian Ocean.

Case report: Perineal swelling: A rare case of scar endometriosis.

We report a rare case of episiotomy site scar endometriosis manifested as painful perineal swelling near the anus for 2 years affecting daily routine activity, especially during menses. A 33-year-old female, para 2 with both vaginal deliveries with last child birth 8 years back. A 2.5 × 3 cm firm, tender nodule was present on the posterior vulva at the right mediolateral episiotomy site. Trans-perineal and trans-anal ultrasound scan was done, anal sphincter involvement was ruled out and the nodule was excised with free margins. histopathology confirmed the diagnosis of scar endometriosis. The key takeaway from this case is endometriosis can present after 8 years of vaginal delivery. The timely diagnosis and treatment is necessary as delay may cause anal sphincter involvement or malignant transformation.

In-situ analysis of sub-nanomolar level of Fe(II) in open-ocean waters.

Iron (Fe) in seawater is an essential micronutrient for marine phytoplankton, and Fe deficiency limits their growth in high-nutrient, low-chlorophyll areas. The bioavailability of Fe for phytoplankton largely depends on its chemical speciation in seawater. In surface water, the reduction of Fe(III) to Fe(II) is an important step in the uptake of Fe by phytoplankton. However, the marine biogeochemical cycle of Fe(II) in the open ocean has not been fully investigated. In oxic open-ocean waters, Fe(II) is rapidly oxidized and exists at sub-nanomolar levels, making it difficult to determine the Fe(II) concentration of seawater. In this study, we applied the flow analytical method of determining the Fe(II) concentration of seawater using luminol chemiluminescence in an in-situ analyzer (geochemical anomaly monitoring system, GAMOS). In the onboard laboratory, we successfully detected sub-nanomolar levels of Fe(II) in seawater using the GAMOS. In the central Indian Ocean, this analyzer was deployed at a depth of 1000 m to determine the Fe(II) concentration in the water column. During deployment, the detection limit (0.48 nM) was insufficient to determine the concentration. Therefore, we need to lower the blank values and enhance the stability of signal of the in-situ analytical method for application to open-ocean seawater samples.

Decoupling of carbon burial from productivity in the northeast Indian Ocean.

The concentration of atmospheric carbon dioxide (CO2) is a crucial climate parameter as it has far-reaching implications on global temperature. The oceans are a significant sink for CO2. Biologically mediated carbon sequestration, in the form of both inorganic (CaCO3) and organic carbon (Corg), and its subsequent burial in marine sediments play a vital role in regulating atmospheric CO2. Understanding the distribution of carbon in marine sediments under different environments can help predict the fate of excess CO2 in the future. We studied the factors affecting the basin scale variation in carbon burial in the climatically sensitive northeast Indian Ocean, by using the data [CaCO3, Corg, Corg/Nitrogen, and isotopic ratio (δ13C, δ15N) of organic carbon] from a total of 718 surface sediments. The entire continental shelf and slope contain <10 % CaCO3. The highest CaCO3 is in the deepest parts of the central northeast Indian Ocean, away from the mouth of major river systems. Despite of the high productivity, the low Corg on the continental shelf is attributed to the well-oxygenated coarse-grained sediments. The lowest Corg is found in the well-oxygenated deeper central northeast Indian Ocean. Interestingly, the highest total carbon is in the deeper central and equatorial regions, far away from the highly productive marginal marine regions. Our study reveals that the grain size, terrigenous dilution, dissolved oxygen, and water masses strongly influence carbon accumulation in the northeast Indian Ocean, with only secondary influence of the productivity.

An underwater imagery identification guide for shallow, mesophotic and deep-sea benthos in Maldives.

Background: During the 2022 Nekton Maldives Mission, we deployed a variety of platforms (snorkelling, remotely-operated vehicles and manned submersibles) to conduct video surveys of the biodiversity and composition of shallow (< 30 m), mesophotic (30-150 m) and deep-sea (> 150 m) benthos found in the Maldives' central and southern atolls. In total, ~ 80 hrs of stereo-video footage were collected during the benthic transect surveys, which were subsequently processed using annotation software in order to evaluate benthic biodiversity and community composition. Here, we present a photographic guide for the visual, in situ identification of reef benthos encountered, including corals, sponges and other invertebrates that inhabit Maldives' nearshore habitats. We hope that this identification guide will aid future imagery-based surveys or observations of organisms during fieldwork. New information: A total of 283 morphotypes were identified, including those belonging to Octocorallia (61), Scleractinia (57), Porifera (38), Asteroidea (22), Antipatharia (15), Decapoda (13), Hydrozoa (12), Holothuroidea (10), Actiniaria (9), Echinoidea (8), Annelida (6), Chlorophyta (5), Gastropoda (4), Bivalvia (4), Ascidiacea (3), Crinoidea (3), Bryozoa (2), Cyanobacteria (2), Zoantharia (2), Cephalopoda (1), Ceriantharia (1), Corallimorpharia (1), Ctenophora (1), Ophiuroidea (1), Rhodophyta (1) and to an unknown category (1). Out of these, we identified 40 to species level, 120 to genus, 47 to family, 14 to order and suborder, 58 to class and subclass, two to phylum and one was of unknown phylum. This represents the first attempt to catalogue the mesophotic and deep-sea benthic megafaunal diversity in the Maldives using underwater imagery.

Corrigendum: Comprehensive analysis of antimicrobial resistance in the Southwest Indian Ocean: focus on WHO critical and high priority pathogens.

[This corrects the article DOI: 10.3389/fpubh.2024.1357345.].

Does the microplastics ingestion patterns and polymer composition vary across the oceanic zones? A case study from the Indian coast.

This study explores microplastic (MP) presence in the gastrointestinal tracts of deep-sea fish from the Central Indian Ocean, off the Indian coast. Among the 27 species examined, 19 showed MP contamination, averaging 2.68 ± 0.30 (±SE) MPs per individual. Polymer analysis via FTIR and micro-Raman identified several types, including polyethylene terephthalate (PET), polyvinyl alcohol (PVA), polypropelene (PP), polyvinyl acetate (PVC), polyurethane (PU), polytetrafluoroethylene (PTFE), polyaniline (PANI), polymethyl methacrylate (PMMA), and polyethersulfone (PES), with PET being the most prevalent (33.33 %). MP ingestion was higher in benthopelagic fish and those at higher trophic levels, as indicated by comparisons across oceanic zones. Niche partitioning analysis suggests feeding behaviour as a primary influencer of MP ingestion in deep-sea fish rather than habitat or trophic level. The study proposes the potential use of deep-sea fish as indicators for assessing microplastic pollution across oceanic zones and deep-sea regions through bycatch monitoring.

Comparative analysis of microbiome inhabiting oxygenated and deoxygenated habitats using V3 and V6 metabarcoding of 16S rRNA gene.

We examine how oxygen levels and the choice of 16S ribosomal RNA (rRNA) tags impact marine bacterial communities using Next-Generation amplicon sequencing. Analyzing V3 and V6 regions, we assess microbial composition in both Oxygen minimum zones (OMZ) and non-OMZ (NOMZ) areas in the Arabian Sea (AS) and the Central Indian Ocean basin (CIOB) respectively. Operational taxonomic units (OTUs) at 97% similarity showed slightly higher richness and diversity with V6 compared to V3. Vertical diversity patterns were consistent across both regions. NOMZ showed greater richness and diversity than OMZ. AS and CIOB exhibited significant differences in bacterial community, diversity, and relative abundance at the order and family levels. Alteromonadaceae dominated the OMZ, while Pelagibacteraceae dominated the NOMZ. Synechococcaceae were found exclusively at 250 m in OMZ. Bacteria putatively involved in nitrification, denitrification, and sulfurylation were detected at both sites. Dissolved oxygen significantly influenced microbial diversity at both sites, while seasonal environmental parameters affected diversity consistently, with no observed temporal variation.

Phylogenomic analysis expands the known repertoire of single-stranded DNA viruses in benthic zones of the South Indian Ocean.

Single-stranded (ss) DNA viruses are ubiquitous and constitute some of the most diverse entities on Earth. Most studies have focused on ssDNA viruses from terrestrial environments resulting in a significant deficit in benthic ecosystems including aphotic zones of the South Indian Ocean (SIO). Here, we assess the diversity and phylogeny of ssDNA in deep waters of the SIO using a combination of established viral taxonomy tools and a Hidden Markov Model based approach. Replication initiator protein-associated (Rep) phylogenetic reconstruction and sequence similarity networks were used to show that the SIO hosts divergent and as yet unknown circular Rep-encoding ssDNA viruses. Several sequences appear to represent entirely novel families, expanding the repertoire of known ssDNA viruses. Results suggest that a small proportion of these viruses may be circular genetic elements, which may strongly influence the diversity of both eukaryotes and prokaryotes in the SIO. Taken together, our data show that the SIO harbours a diverse assortment of previously unknown ssDNA viruses. Due to their potential to infect a variety of hosts, these viruses may be crucial for marine nutrient recycling through their influence of the biological carbon pump.

Time series (2003-15) analysis of selected physicochemical parameters in Indian Ocean: Cumulative impacts prediction on coral bleaching using machine learning.

Coral bleaching is an important ecological threat worldwide, as the coral ecosystem supports a rich marine biodiversity to survive. Sea surface temperature was considered a major culprit; however, later it was observed that other water parameters like pH, tCO2, fCO2, salinity, dissolved oxygen, etc. also play a significant role in bleaching. In the present study, all these parameters of the Indian Ocean area for 15 years (2003-2017) were collected and analysed using machine learning language. The main aim is to see the cumulative impacts of various ocean parameters on coral bleaching. Introducing machine learning in environmental impact assessment studies is a new approach, and the prediction of coral bleaching using simulation of physico-chemical parameters interactions shows 94.4 % accuracy for the prediction of the future bleaching event. This study can be probably the first step in the application of the machine learning language for the prediction of coral bleaching in the field of marine science.

Big brands impact small islands: Sources of plastic pollution in a remote and protected archipelago.

Remote islands are disproportionately affected by plastic pollution, often originating from elsewhere, so it is important to understand its origins, to stop debris entering the ocean at their source. We investigated the origins of beached plastic drink bottles in the Chagos Archipelago, a large remote Marine Protected Area (MPA) in the Indian Ocean. We recorded the brands, countries of manufacture, types of drink, and ages of plastic bottles and their lids. The prevalent type of drink was water, with items mostly manufactured in Indonesia, China, and the Maldives. The main brands were Danone and the Coca-Cola Company. We deduced that 10 % of the items originated from ships passing the archipelago, including all the items manufactured in China. The identification of the brands creating plastic pollution in remote MPAs with high biodiversity supports extended producer responsibility, one of the proposed policy development areas of the Global Plastics Treaty.

Roseihalotalea indica gen. nov., sp. nov., a halophilic Bacteroidetes from mesopelagic Southwest Indian Ocean with higher carbohydrate metabolic potential.

The pink-colored and strictly aerobic bacterium strain, designated as TK19036T, was isolated from mesopelagic layer of the Southwest Indian Ocean. This novel isolate can grow at 10-45 °C (optimum, 30 °C), pH 6.0-8.0 (optimum, pH 7.0), and 2-14% NaCl concentrations (w/v) (optimum, 6%). The predominant respiratory quinone was Menaquinone-7. Major polar lipid profiles contained two aminolipids, aminophospholipid, two glycolipids, phosphatidylethanolamine, and three unknown polar lipids. The preponderant cellular fatty acids were iso-C15:0, C16:1 ω5c and iso-C17:0 3-OH. Phylogenetic analyses based on 16S rRNA gene sequence uncovered that the strain TK19036T pertained to the family Catalinimonadaceae under phylum Bacteroidota, and formed a distinct lineage with the closed species Tunicatimonas pelagia NBRC 107804T. The up-to-bacteria-core gene phylogenetic trees also demonstrated a deep and novel branch formed by the strain TK19036T within the family Catalinimonadaceae. Based on chemotaxonomic, phylogenetic and genomic features presented above, strain TK19036T represents a novel species from a novel genus of the family Catalinimonadaceae, for which the name Roseihalotalea indica gen. nov. sp. nov. is proposed. The type strain is TK19036T (= CGMCC 1.18940T = NBRC 116371T).

Microplastics in the Indian and South Atlantic oceans translocate to gills, digestive glands, and muscle of the chokka squid Loligo reynaudii.

Comparative microplastic (MP) data for cephalopods between oceans is scarce. Our aim was to quantify, characterise, and compare MPs in gills, digestive gland, and mantle of chokka squid from the South Atlantic Ocean (SAO) and Indian Ocean (IO) off the coast of South Africa. South African squid had more MPs compared with other studies (means = 2.0 and 0.4 in SAO and IO squid mantle, respectively). Blue fibres were dominant. Identifiable MPs were polyethylene. Despite IO water having higher MP concentrations than the SAO, SAO squid had higher MP concentrations. Dilution by growth is the likely reason for the lower MP concentrations. Fibres were shorter in SAO than IO squid. However, we could not explain why fibre and mantle lengths from both oceans were positively correlated. Squid may not be the best indicator of marine MPs. The characteristics of MPs in squid can be used to track stocks and migrations.