Marine Group Research Articles

Diverse and unique viruses discovered in the surface water of the East China Sea

BackgroundViruses are the most abundant biological entities on earth and play import roles in marine biogeochemical cycles. Here, viral communities in the surface water of the East China Sea (ECS) were collected from three representative regions of Yangshan Harbor (YSH), Gouqi Island (GQI), and the Yangtze River Estuary (YRE) and explored primarily through epifluorescence microscopy (EM), transmission electron microscopy (TEM), and metagenomics analysis.ResultsThe virus-like particles (VLPs) in the surface water of the ECS were measured to be 106 to 107 VLPs/ml. Most of the isolated viral particles possessed a head-and-tail structure, but VLPs with unique morphotypes that had never before been observed in the realm of viruses were also found. The sequences related to known viruses in GenBank accounted for 21.1–22.8% of the viromic datasets from YSH, GQI, and YRE. In total, 1029 viral species were identified in the surface waters of the ECS. Among them, tailed phages turn out to make up the majority of viral communities, however a small number of Phycodnaviridae or Mimiviridae related sequences were also detected. The diversity of viruses did not appear to be a big difference among these three aquatic environments but their relative abundance was geographically variable. For example, the Pelagibacter phage HTVC010P accounted for 50.4% of the identified viral species in GQI, but only 9.1% in YSH and 11.7% in YRE. Sequences, almost identical to those of uncultured marine thaumarchaeal dsDNA viruses and magroviruses that infect Marine Group II Euryarchaeota, were confidently detected in the ECS viromes. The predominant classes of virome ORFs with functional annotations that were found were those involved in viral biogenesis. Virus-host connections, inferred from CRISPR spacer-protospacer mapping, implied newly discovered infection relationships in response to arms race between them.ConclusionsTogether, both identified viruses and unknown viral assemblages observed in this study were indicative of the complex viral community composition found in the ECS. This finding fills a major gap in the dark world of oceanic viruses of China and additionally contributes to the better understanding of global marine viral diversity, composition, and distribution.

Within-family plasticity of nervous system architecture in Syllidae (Annelida, Errantia)

BackgroundThe ground pattern underlying the nervous system of the last common ancestor in annelids was long thought to be settled, consisting of a dorsal brain, circumoesophageal connectives and a subepithelial, ladder-like ventral nerve cord with segmental ganglia connected by paired connectives. With the advent of immunocytochemical stainings and confocal laser scanning microscopy, it becomes evident that its architecture is extremely diverse, which makes the reconstruction of a ground pattern in annelida challenging. Whereas the nervous systems of many different families has already been described, only very few studies looked at the diversity of nervous systems within such clades to give a closer estimate on how plastic the annelid nervous system really is. So far, little is known on syllid nervous system architecture, one of the largest and most diverse groups of marine annelids.ResultsThe position of the brain, the circumoesophageal connectives, the stomatogastric nervous system, the longitudinal nerves that traverse each segment and the innervation of appendages are relatively uniform within the clade. Both the number of connectives within the ventral nerve cord and the number of segmental nerves, which in earlier studies were used to infer phylogenetic relationships and to reconstruct an annelid ground pattern, are highly diverse and differ between genera or even within a given genus. Differences in the distribution of somata of the brain, the nuchal innervation and its associated cell bodies were found between Syllinae and Exogoninae and may be subfamily-specific.ConclusionsThe nervous system morphology of syllids very likely depends on the taxon-specific ecological requirements. Thus, it is not surprising that in a clade, which occupies such diverse niches as the Annelida, we find similar patterns in phylogenetically widely separated species in similar niches and a high degree of modularity within a family. Only standardized protocols and staining methods can lead to comparable results, but so far different approaches have been taken to describe annelid nervous systems, making homologization of certain structures difficult. This study provides the first thorough description of the nervous system in the family Syllidae, allowing more detailed comparisons between annelid families in the future.

Study of pyrite based autotrophic denitrification system for low-carbon source stormwater treatment

Improving the nitrogen removal capacity of stormwater runoff has been the main research direction of bioretention systems in recent years. Heterotrophic denitrification in traditional bioretention systems was often used, but insufficient carbon sources in the runoff limit it. In this study, two bioretention systems using natural pyrite and zeolite as substrates were constructed to explore the feasibility of pyrite-based autotrophic denitrification in bioretention for nitrogen removal. During eight months of operation at natural conditions, the results showed that pyrite had no negative effects on the removal of NH4+—N, but enhanced denitrification in the bioretention system with no or low carbon source in the influent. Pyrite based bioretention system (PBS) can adapt to low temperature and irregular wet and dry alternation. The average NH4+—N, TN, and TP removal efficiency of PBS during eight months were 87.6 %, 89.3 %, and 81.6 %. The average NH4+—N, TN, and TP removal efficiency of zeolite-based bioretention system (ZBS) were 98.7 %, 47.1 %, and 47.5 %. By-products (SO42- and Total iron) of PBS were all at an acceptable level. The dominant genera in PBS were Denitratisoma (3.6 %), Ellin6067 (2.7 %), Thiobacillus (2.6 %), Thauera (2.1 %), CL500−29 marine group (1.8 %), Sulfuritalea (1.7 %), Subgroup 10 (1.4 %). Genera Thiobacillus, Thauera, and Sulfuritalea were highly related to autotrophic denitrification. Moreover, genera Denitratisoma was highly related to heterotrophic denitrification. This study shows that pyrite could be a promising eco-friendly substrate in the bioretention system for nutrient removal.

Marine Group II Euryarchaeota Contribute to the Archaeal Lipid Pool in Northwestern Pacific Ocean Surface Waters.

Planktonic archaea include predominantly Marine Group I Thaumarchaeota (MG I) and Marine Group II Euryarchaeota (MG II), which play important roles in the oceanic carbon cycle. MG I produce specific lipids called isoprenoid glycerol dibiphytanyl glycerol tetraethers (GDGTs), which are being used in the sea surface temperature proxy named TEX86. Although MG II may be the most abundant planktonic archaeal group in surface water, their lipid composition remains poorly characterized because of the lack of cultured representatives. Circumstantial evidence from previous studies of marine suspended particulate matter suggests that MG II may produce both GDGTs and archaeol-based lipids. In this study, integration of the 16S rRNA gene quantification and sequencing and lipid analysis demonstrated that MG II contributed significantly to the pool of archaeal tetraether lipids in samples collected from MG II-dominated surface waters of the Northwestern Pacific Ocean (NWPO). The archaeal lipid composition in MG II-dominated NWPO waters differed significantly from that of known MG I cultures, containing relatively more 2G-OH-, 2G- and 1G- GDGTs, especially in their acyclic form. Lipid composition in NWPO waters was also markedly different from MG I-dominated surface water samples collected in the East China Sea. GDGTs from MG II-dominated samples seemed to respond to temperature similarly to GDGTs from the MG I-dominated samples, which calls for further study using pure cultures to determine the exact impact of MG II on GDGT-based proxies.

Spatial Distribution Patterns of Bacterioplankton in the Oxygen Minimum Zone of the Tropical Mexican Pacific.

Microbial communities within oxygen minimum zones (OMZs) are crucial drivers of marine biogeochemical cycles; however, we still lack an understanding of how these communities are distributed across an OMZ. We explored vertical (from 5 to 500m depth) and horizontal (coast to open ocean) distribution of bacterioplankton and its relationships with the main oceanographic conditions in three transects of the tropical Mexican Pacific OMZ. The distribution of the microbial diversity and the main clades changed along the transition from oxygen-rich surface water to the OMZ core, demonstrating the sensitivity of key bacterial groups to deoxygenation. The euphotic zone was dominated by Synechococcales, followed by Flavobacteriales, Verrucomicrobiales, Rhodobacterales, SAR86, and Cellvibrionales, whereas the OMZ core was dominated by SAR11, followed by SAR406, SAR324, SAR202, UBA10353 marine group, Thiomicrospirales and Nitrospinales. The marked environmental gradients along the water column also supported a high potential for niche partitioning among OMZ microorganisms. Additionally, in the OMZ core, bacterial assemblages from the same water mass were more similar to each other than those from another water mass. There were also important differences between coastal and open-ocean communities: Flavobacteriales, Verrucomicrobiales, Rhodobacterales, SAR86, and Cellvibrionales were more abundant in coastal areas, while Synechococcales, SAR406, SAR324, SAR202, UBA10353 marine group, and Thiomicrospirales were more abundant in the open ocean. Our results suggest a biogeographic structure of the bacterioplankton in this OMZ region, with limited community mixing across water masses, except in upwelling events, and little dispersion of the community by currents in the euphotic zone.

A Screening Tool for the Direct Analysis of Marine and Freshwater Phycotoxins in Organic SPATT Extracts from the Chesapeake Bay.

Many detection methods for phycotoxins, bioactive compounds produced by harmful algae, focus on one compound or a class of related compounds. Multiple harmful algal species often co-occur in the environment, however, emphasizing the need to analyze for the presence of multiple groups of marine and freshwater phycotoxins in environmental samples, e.g., extracts from solid phase adsorption toxin tracking (SPATT). Two methods were developed to screen for 13 phycotoxins (microcystin-RR, -LR, -YR, azaspiracid-1, -2, karlotoxin 3, goniodomin A, brevetoxin-2, yessotoxin, pectenotoxin-2, dinophysistoxin-1, -2, and okadaic acid) in organic SPATT extracts using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) equipped with a trapping dimension (trap) and at-column dilution (ACD). The performance of each compound under 36 combinations of chromatographic conditions was characterized, and two final methods, acidic and basic, were selected based on peak shapes, signal intensities, resolution, and the separation in time of positive and negative MS ionization modes. Injection volumes of up to 1 mL were possible through trap/ACD technology, resulting in limits of detection between 0.001 and 0.05 µg/L across the analytes. Benefits highlighted in this study, beyond the improved detection limits and co-detection of multiple toxin groups, include the ability to inject samples of 100% organic solvent, ensuring analyte stability and streamlining workflow through the elimination of laborious sample preparation steps.

ASLO 2020 Award Winners

<scp>ASLO</scp> 2020 Award Winners

Large-bodied sabre-toothed anchovies reveal unanticipated ecological diversity in early Palaeogene teleosts.

Many modern groups of marine fishes first appear in the fossil record during the early Palaeogene (66–40 Ma), including iconic predatory lineages of spiny-rayed fishes that appear to have originated in response to ecological roles left empty after the Cretaceous/Palaeogene extinction. The hypothesis of extinction-mediated ecological release likewise predicts that other fish groups have adopted novel predatory ecologies. Here, we report remarkable trophic innovation in early Palaeogene clupeiforms (herrings and allies), a group whose modern representatives are generally small-bodied planktivores. Two forms, the early Eocene (Ypresian) †Clupeopsis from Belgium and a new genus from the middle Eocene (Lutetian) of Pakistan, bear conspicuous features indicative of predatory ecology, including large size, long gapes and caniniform dentition. Most remarkable is the presence of a single, massive vomerine fang offset from the midline in both. Numerous features of the neurocranium, suspensorium and branchial skeleton place these taxa on the engraulid (anchovy) stem as the earliest known representatives of the clade. The identification of large-bodied, piscivorous anchovies contributes to an emerging picture of a phylogenetically diverse guild of predatory ray-finned fishes in early Palaeogene marine settings, which include completely extinct lineages alongside members of modern marine groups and taxa that are today restricted to freshwater or deep-sea environments.

Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin

In deep ocean hypersaline basins, the combination of high salinity, unusual ionic composition and anoxic conditions represents significant challenges for microbial life. We used geochemical porewater characterization and DNA sequencing based taxonomic surveys to enable environmental and microbial characterization of anoxic hypersaline sediments and brines in the Orca Basin, the largest brine basin in the Gulf of Mexico. Full-length bacterial 16S rRNA gene clone libraries from hypersaline sediments and the overlying brine were dominated by the uncultured halophilic KB1 lineage, Deltaproteobacteria related to cultured sulfate-reducing halophilic genera, and specific lineages of heterotrophic Bacteroidetes. Archaeal clones were dominated by members of the halophilic methanogen genus Methanohalophilus, and the ammonia-oxidizing Marine Group I (MG-I) within the Thaumarchaeota. Illumina sequencing revealed higher phylum- and subphylum-level complexity, especially in lower-salinity sediments from the Orca Basin slope. Illumina and clone library surveys consistently detected MG-I Thaumarchaeota and halotolerant Deltaproteobacteria in the hypersaline anoxic sediments, but relative abundances of the KB1 lineage differed between the two sequencing methods. The stable isotopic composition of dissolved inorganic carbon and methane in porewater, and sulfate concentrations decreasing downcore indicated methanogenesis and sulfate reduction in the anoxic sediments. While anaerobic microbial processes likely occur at low rates near their maximal salinity thresholds in Orca Basin, long-term accumulation of reaction products leads to high methane concentrations and reducing conditions within the Orca Basin brine and sediments.

River bacterial community structure and co-occurrence patterns under the influence of different domestic sewage types

Bacterial communities play a critical role in food webs and the biogeochemical cycles of fundamental elements. However, there remains a substantial gap in our knowledge of the anthropogenic impacts on bacterial co-occurrence patterns and ecosystem functions. In this study, we used Illumina high-throughput sequencing to characterize and compare the diversity, composition, co-occurrence patterns, and functional changes in bacterial communities in the Qingliu River under the influence of different types of domestic sewage. Twelve samples had similar dominant phyla, mainly Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes, differing only in the proportions of the microorganisms. However, there was a large difference at the genus level, for example, the relative abundance of the genus Dechloromonas in the school sewage water samples (XXW) was much higher than that in the other samples, the genus Chryseobacterium was the dominant bacteria in the residential sewage water samples (JMW), and there were significant differences between the different samples (P < 0.01). This may indicate that external pollution and environmental induction deeply affect the bacterial community assembly in rivers. Network analysis showed that the river bacterial co-occurrence network has a modular structure (divided into 6 modules), and that the microbial taxonomic units from the same module were involved in the carbon and nitrogen cycle (e.g., the CL500-29 marine group and the genus Pseudomonas) and degradation of organic pollutants and toxic compounds (e.g., the genera Massilia and Exiguobacterium). Functional predictions indicate that the function of ABC transporter was highest in the hospital sewage water samples (YYW), while two-component system was more abundant in the XXW samples. In summary, our research provides a new perspective of community assembly in rivers under the influence of human activity.

Within-Generation Polygenic Selection Shapes Fitness-Related Traits across Environments in Juvenile Sea Bream.

Understanding the genetic underpinnings of fitness trade-offs across spatially variable environments remains a major challenge in evolutionary biology. In Mediterranean gilthead sea bream, first-year juveniles use various marine and brackish lagoon nursery habitats characterized by a trade-off between food availability and environmental disturbance. Phenotypic differences among juveniles foraging in different habitats rapidly appear after larval settlement, but the relative role of local selection and plasticity in phenotypic variation remains unclear. Here, we combine phenotypic and genetic data to address this question. We first report correlations of opposite signs between growth and condition depending on juvenile habitat type. Then, we use single nucleotide polymorphism (SNP) data obtained by Restriction Associated DNA (RAD) sequencing to search for allele frequency changes caused by a single generation of spatially varying selection between habitats. We found evidence for moderate selection operating at multiple loci showing subtle allele frequency shifts between groups of marine and brackish juveniles. We identified subsets of candidate outlier SNPs that, in interaction with habitat type, additively explain up to 3.8% of the variance in juvenile growth and 8.7% in juvenile condition; these SNPs also explained significant fraction of growth rate in an independent larval sample. Our results indicate that selective mortality across environments during early-life stages involves complex trade-offs between alternative growth strategies.

A halo of reduced dinoflagellate abundances in and around eelgrass beds.

Seagrass beds provide a variety of ecosystem services, both within and outside the bounds of the habitat itself. Here we use environmental DNA (eDNA) amplicons to analyze a broad cross-section of taxa from ecological communities in and immediately surrounding eelgrass (Zostera marina). Sampling seawater along transects extending alongshore outward from eelgrass beds, we demonstrate that eDNA provides meter-scale resolution of communities in the field. We evaluate eDNA abundance indices for 13 major phylogenetic groups of marine and estuarine taxa along these transects, finding highly local changes linked with proximity to Z. marina for a diverse group of dinoflagellates, and for no other group of taxa. Eelgrass habitat is consistently associated with dramatic reductions in dinoflagellate abundance both within the contiguous beds and for at least 15 m outside, relative to nearby sites without eelgrass. These results are consistent with the hypothesis that eelgrass-associated communities have allelopathic effects on dinoflagellates, and that these effects can extend in a halo beyond the bounds of the contiguous beds. Because many dinoflagellates are capable of forming harmful algal blooms (HABs) toxic to humans and other animal species, the apparent salutary effect of eelgrass habitat on neighboring waters has important implications for public health as well as shellfish aquaculture and harvesting.

Autotrophic carbon fixation pathways along the redox gradient in oxygen-depleted oceanic waters.

SummaryAnoxic marine zones (AMZs), also known as ‘oxygen‐deficient zones’, contribute to the loss of fixed nitrogen from the ocean by anaerobic microbial processes. While these microbial processes associated with the nitrogen cycle have been extensively studied, those linked to the carbon cycle in AMZs have received much less attention, particularly the autotrophic carbon fixation — a crucial component of the carbon cycle. Using metagenomic and metatranscriptomic data from major AMZs, we report an explicit partitioning of the marker genes associated with different autotrophic carbon fixation pathways along the redox gradient (from oxic to anoxic conditions) present in the water column of AMZs. Sequences related to the Calvin‐Benson‐Bassham cycle were found along the entire gradient, while those related to the reductive Acetyl‐CoA pathway were restricted to suboxic and anoxic waters. Sequences putatively associated with the 3‐hydroxypropionate/4‐hydroxybutyrate cycle dominated in the upper and lower oxyclines. Genes related to the reductive tricarboxylic acid cycle were represented from dysoxic to anoxic waters. The taxonomic affiliation of the sequences is consistent with the presence of microorganisms involved in crucial steps of biogeochemical cycles in AMZs, such as the gamma‐proteobacteria sulfur oxidisers, the anammox bacteria Candidatus Scalindua and the thaumarcheota ammonia oxidisers of the Marine Group I.

Inconspicuous genetic and morphological patterns challenge the taxonomic status of endemic species Bodianus insularis (Labridae)

Bodianus constitutes a marine fish group of particular interest due to its trophic interactions with reef environments. Knowledge of phylogenetic relationships of this genus have been improved by shared advances of classical and genetic approaches. However, some of its species have yet to be compared regarding its genetic patterns. Morphological variations in body shape and color patterns during the course of ontogenetic development, in addition to recurring sex reversal in species of this genus, make its taxonomy challenging. In the Atlantic Ocean five species have been described: Bodianus scrofa and Bodianus speciosus (Eastern Atlantic), Bodianus rufus (Western Atlantic), Bodianus pulchellus (Western Atlantic and Eastern Atlantic Islands) and Bodianus insularis (Mid-Atlantic islands). The phylogenetic relationships of the last species could not be resolved using genetic analyses. With a very restrict geographic distribution, B. insularis deserves high attention regarding its taxonomic and evolutionary aspects. Here, we use mitochondrial DNA sequences (COI and 16S rRNA) and nuclear analyses (rhodopsin) to assess the genetic divergence of B. insularis in relation to other Atlantic species and clarify its phylogenetic relationships. Bodianus pulchellus and B. insularis were not genetically distinct and are grouped with B. rufus, forming a sister clade of B. speciosus, while B. scrofa is more related to Pacific species. DNA-based and morphological traits are very similar between B. insularis and B. pulchellus, whose most obvious difference is their color pattern. The actual reinterpretation of ecological and biogeographic contexts allows to suggest that B. insularis is most likely a synonym of B. pulchellus, constituting a population enclave of this species.

Unique microbial module regulates the harmful algal bloom (Cochlodinium polykrikoides) and shifts the microbial community along the Southern Coast of Korea

Harmful algal blooms (HABs) of Cochlodinium (aka Margalefidinium) polykrikoides cause huge economic and ecological damages and thus are considered environmental problems. Previous studies uncovered that the formation and collapse of phytoplankton blooms could be closely related to their associated microbes although their roles in C. polykrikoides bloom have not been elucidated yet. To explore the potential interactions between C. polykrikoides and other microbes (archaea, bacteria, and phytoplankton), we collected water samples in the free-living (FL) (0.22 to 3 μm), nanoparticle-associated (NP) (3 to 20 μm), and microparticle-associated (MP) (>20 μm) fractions when C. polykrikoides blooms occurred from July to August in 2016, 2017, and 2018 in the South Sea of Korea. The microbial composition of the C. polykrikoides-associated microbial cluster (Module I) significantly differed from those of other modules associated with Alexandrium, Chaetoceros or Chattonella. Over half of the interspecies interactions in Module I occurred within the module. That is, specific microbial clusters were associated with the C. polykrikoides bloom. Structural equation modeling (SEM) further confirmed the stronger effects of Module I on C. polykrikoides blooms compared to environmental factors. Among the operational taxonomic units (OTUs) directly correlated with C. polykrikoides, Marine Group I was presumed to supply vitamin B12, the essential element for C. polykrikoides growth, while the potential fish pathogens (Micrococcaceae and Piscirickettsiaceae) could contribute to the massive fish death together with C. polykrikoides itself. In addition, the zoospores of Syndiniales, a parasitoid to dinoflagellates, might be related to the sudden collapse of C. polykrikoides blooms. These microbial groups also contributed to significant alterations of the local microbial community structures. Collectively, network analysis and SEM revealed that the C. polykrikoides bloom is concomitant with distinct microbial communities, contributing to the rise and fall of the bloom, and finally determining the local microbial community structures.

Ecologically diverse clades dominate the oceans via extinction resistance.

Ecological differentiation is correlated with taxonomic diversity in many clades, and ecological divergence is often assumed to be a cause and/or consequence of high speciation rate. However, an analysis of 30,074 genera of living marine animals and 19,992 genera of fossil marine animals indicates that greater ecological differentiation in the modern oceans is actually associated with lower rates of origination over evolutionary time. Ecologically differentiated clades became taxonomically diverse over time because they were better buffered against extinction, particularly during mass extinctions, which primarily affected genus-rich, ecologically homogeneous clades. The relationship between ecological differentiation and taxonomic richness was weak early in the evolution of animals but has strengthened over geological time as successive extinction events reshaped the marine fauna.

Phenological shuffling of major marine phytoplankton groups over the last six decades

AbstractAimPhytoplankton form the basis of the marine food web and are responsible for approximately 50% of the world's photosynthesis. Changes to their ecology are, therefore, important: here, we examined seasonal patterns in ocean phytoplankton abundance for 45 taxa over 59 years collected from circa 410,000 km of line‐transect sampling at temperate latitudes.LocationThe North Sea.MethodsFor our analysis we used plankton abundance data from the Continuous Plankton Recorder (CPR) survey, sea surface temperature measurements from the Hadley Centre, UK Meteorological Office and wind speed data from the International Comprehensive Ocean–Atmosphere Data Set, NOAA.ResultsWe found large differences in changes in the timing of peak abundance between the major phytoplankton groups. Late‐summer blooming dinoflagellates (n = 10 taxa) tended to show a large seasonal advancement, the timing of peak abundance for dinoflagellates as group advancing 39 days over these six decades. By contrast diatoms (n = 35) did not show any change as a group in their timing of peak abundance over the time series. Granger causality testing suggested a major driver of these phenological changes has been ocean warming in general but more specifically the rate of spring temperature rise as the most important factor. We also found differences in the timing of peak abundance of harmful algal bloom taxa, with some showing peak abundance earlier while others have moved later.Main conclusionsThere has been a fundamental transformation of the classic seasonal progression from blooms of diatoms to dinoflagellates, which lies at the heart of temperate marine food chains, as the classic bimodal diatom and dinoflagellate seasonal peaks are eroded to a more continuous, single, longer‐lasting phytoplankton peak. This phenological shuffling within and between major taxonomic groups is likely to have profound implications for the transfer of energy to higher trophic levels.

Distinct Responses of Elasmobranchs and Ray-Finned Fishes to Long-Term Global Change

Both biotic and abiotic factors likely played a role in influencing the diversification patterns of clades. Although the role of environmental forcing on the long-term evolution of biodiversity has been explored for invertebrate clades, little is known about how vertebrates groups responded to environmental changes. Among vertebrates, fishes (ray-finned fishes and elasmobranchs) have a long, rich and complex evolutionary history comprising numerous diversification and extinction events. Yet, knowledge on the causes for the diversity fluctuations of these most speciose aquatic vertebrate clades in modern marine and continental ecosystems were restricted to qualitative interpretations. Here we use multiple regression methods to quantitatively examine the role of six abiotic parameters over the long-term variations of elasmobranch and actinopterygian genus-level diversity. We find that marine actinopterygian diversity is mainly controlled by temperature while continental fragmentation is the primary driver of the diversity fluctuations of elasmobranchs. Sea-level variations correlate positively with the diversity variations of both marine groups, whereas none of the tested proxies explains the diversity variation of freshwater ray-finned fishes. Our results indicate that such contrasting responses are mainly due to ecological and life-history trait differences between these groups.

The absence of intact polar lipid-derived GDGTs in marine waters dominated by Marine Group II: Implications for lipid biosynthesis in Archaea

The marine pelagic archaeal community is dominated by three major groups, the marine group I (MGI) Thaumarchaeota, and the marine groups II and III (MGII and MGIII) Euryarchaeota. Studies of both MGI cultures and the environment have shown that the MGI core membrane lipids are predominantly composed of glycerol dibiphytanyl glycerol tetraether (GDGT) lipids and the diether lipid archaeol. However, there are no cultured representatives of MGII and III archaea and, therefore, both their membrane lipid composition and potential contribution to the marine archaeal lipid pool remain unknown. Here, we show that GDGTs present in suspended particulate matter of the (sub)surface waters of the North Atlantic Ocean and the coastal North Sea are derived from MGI archaea, and that MGII archaea do not significantly contribute to the pool of GDGTs and archaeol. This implies, in contrast to previous suggestions, that their lipids do not affect the widely used sea surface temperature proxy TEX86. These findings also indicate that MGII archaea are not able to produce any known archaeal lipids, implying that our understanding of the evolution of membrane lipid biosynthesis in Archaea is far from complete.

Marine Healing, but Not Additional Intake of Undaria pinnatifida, Benefits Physical and Emotional Exhaustion Symptoms of Menopause.

Menopausal symptoms can persist or worsen even years after menopause and affect women's quality of life. We investigated whether menopausal symptoms were alleviated through a marine healing program and if sea mustard intake additionally benefits these symptoms. A total of 42 menopausal women self-selected to participate as the marine (n = 22) or city group (n = 20). The marine group participated in a 5-day marine healing program consisting of a balanced diet, exercise, and mind-body practices using ocean resources. The city group continued one's daily routine without any intervention. Within the marine group, participants were randomly assigned to consume sea mustard (Undaria pinnatifida) (15.4 g dry weight/day; n = 11) or control (n = 11). Changes in menopausal symptoms were measured using the Menopause Rating Scale (MRS) before, immediately after, and 2 weeks after the end of the marine healing program. The city group completed the MRS at baseline and on day 20. Within subject differences of menopausal symptoms between baseline and immediately after the marine healing program were assessed using paired t-test. Intervention effects were assessed by mixed analysis of variance. Somatic, psychological, and urogenital symptoms were immediately alleviated after the marine healing program. No effect of sea mustard was detected in the marine group. After 2 weeks, the effect of marine healing persisted in physical and mental exhaustion only. A 5-day integrated marine healing program, but not additional sea mustard intake, temporarily alleviated menopausal symptoms. The reduction in physical and mental exhaustion after marine healing can be maintained for 2 weeks.Trial RegistrationClinical Research Information Service Identifier: KCT0004025