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High coastal nutrient loading can cause changes in seagrass chemistry traits that may lead to variability in seagrass litter decomposition processes. Such changes in decomposition have the potential to alter the carbon (C) sequestration capacity within seagrass meadows ('blue carbon'). However, the external and internal factors that drive the variability in decomposition rates of the different organic matter (OM) types of seagrass are poorly understood, especially recalcitrant OM (i.e. cellulose-associated OM and lignin-associated OM), thereby limiting our ability to evaluate the C sequestration potential. It was conducted a laboratory incubation to compare differences in the decomposition of Halophila beccarii litter collected from seagrass meadows with contrasting nutrient loading histories. The exponential decay constants of seagrass litter mass, cellulose-associated OM and lignin-associated OM were 0.009-0.032, 0.014-0.054 and 0.009-0.033 d -1 , respectively. The seagrass litter collected from meadows with high nutrient loading exhibited greater losses of mass (25.0-41.2 %), cellulose-associated OM (2.8-18.5 %) and lignin-associated OM (9.6-31.2 %) than litter from relatively low nutrient loading meadows. The initial and temporal changes of the litter nitrogen (N) and phosphorus (P) concentrations, stoichiometric ratios of lignin/N, C/N, and C/P, and cellulose-associated OM content, were strongly correlated with the losses of litter mass and different types of OM. Further, temporal changes of litter C and OM types, particularly the OM and labile OM concentrations, were identified as the main driving factors for the loss of litter mass and loss of different OM types. These results indicated that nutrient-loaded seagrass litter, characterized by elevated nutrient levels and diminished amounts of recalcitrant OM, exhibits an accelerated decay rate for the recalcitrant OM. These differences in litter quality would lead to a reduced contribution of seagrass litter to long-term C stocks in eutrophic meadows, thereby weakening the stability of C sequestration. Considering the expected changes in seagrass litter chemistry traits and decay rates due to long-term nutrient loading, this study provides useful information for improving C sequestration capabilities through effective pollution management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nanoplastics are ubiquitous in marine environments, exhibiting high bioavailability and potential toxicity to marine organisms. However, the impacts of nanoplastics with various surface modifications on marine microalgae remain largely unexplored. This study explored the toxicity mechanisms of two nanoplastic types-polystyrene (PS) and polymethyl methacrylate (PMMA)-with distinct surface modifications on Skeletonema costatum at cellular and molecular levels. Results showed that nanoplastics significantly impaired the growth of microalgae, particularly PS-NH 2 , which caused the most pronounced growth inhibition, reaching 56.99 % after a 96-h exposure at 50 mg/L. Transcriptomic profiling revealed that nanoplastics disrupted the expression of genes predominantly involved in ribosome biogenesis, aminoacyl-tRNA biosynthesis, amino acid metabolism, and carbohydrate metabolism pathways. The integrated biochemical and transcriptomic evidence highlighted that PS-NH 2 nanoplastics had the most adverse impact on microalgae, affecting fundamental pathways such as ribosome biogenesis, energy metabolism, photosynthesis, and oxidative stress. Our findings underscore the influence of surface-modified nanoplastics on algal growth and contribute new understanding to the toxicity mechanisms of these nanoplastics in marine microalgae, offering critical information for assessing the risks of emerging pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Fishery stock assessment is the basis of fishery management. This study explored the applicability of the Length-Based Spawning Potential Ratio method (LBSPR) to assess the exploitation status of data-limited fisheries. Using data from bottom trawl surveys in Zhanjiang Bay, the study estimated the relative fishing mortality (F/M) of Johnius belangerii stock. The results showed that the average lengths at 50% and 95% selectivity (LS50 and LS95) were 105 mm and 145 mm, respectively, both of which are smaller than the lengths at 50% and 95% sexual maturity length (L50 = 125 mm and L95 = 167 mm) determined via the logistic curve. The estimated spawning potential ratio (SPR) was 0.15 significantly below the reference threshold of 0.2. The study recommended the establishment of a minimum size range (137 to 150 mm) length for harvesting Johnius belangerii to enhance their reproductive potential. It also emphasized the importance of scientific monitoring of fishery resources and the ecological environment in Zhanjiang Bay to ensure sustainable management., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Deng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Marine microplastics pose a significant threat to ecosystems, and deep-sea regions serve as critical sinks for these pollutants. Among these regions, cold seeps harbor relatively high concentrations of microplastics. However, research on the aging of microplastics under low-temperature, dark, methane-abundant, and high-pressure conditions remains limited. Seawater and sediment were collected from various Haima cold seepage sites to simulate seepage environments in 200-mL high-pressure reactors. Four types of microplastics at high concentrations (approximately 10 %) were cultured and monitored over two months to explore how they aged. The key findings are as follows: (1) Compared to areas of weak seepage, methane seepage accelerated microplastic aging, as evidenced by increased surface roughness, enhanced C-O and (CO)-O bond formation, increased microbial colonization, and reduced contact angles. (2) Microplastic aging is more pronounced in sediments than in seawater, with biodegradable polylactic acid (PLA) exhibiting the most significant aging characteristics and carbon contribution. (3) Aged microplastics induce greater disturbances in inorganic nutrient levels than in organic matter, impacting nitrogen cycle processes involving nitrate, nitrite, and ammonium. This study results reveal the fundamental aging characteristics of microplastics in extremely deep seas and highlight their potential ecological effects., Competing Interests: Declaration of Competing Interest We declare that we have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pipefish is traditionally used in Chinese folklore as a male tonic. Recent studies show that Syngnathus schlegeli extracts effectively combat benign prostatic hyperplasia (BPH). However, the specific active compounds involved and their mechanisms of action are not fully understood. This study aimed to investigate how pipefish peptides alleviate BPH using network pharmacology, molecular docking, and quantum chemical techniques. SN4, a gel-separated fraction from the neutral enzymatic hydrolysates of S. schlegeli, reveal 3470 peptide sequences, predominantly tetrapeptides enriched in Phe, Trp, Leu, and Ile. Network pharmacology identified SRC, AKT, and ITGB3 as primary targets. Molecular docking and in vitro tests on TP-induced RWPE-1 cell proliferation showed that peptides (FVDW, FIFE) were potentially active. In silico docking and quantum chemistry analysis showed that the N-terminal Phe linked to Ile/Val in FVDW and FIFE interacted with AKT1, ITGB3, and SRC proteins, enhancing ligand-receptor interactions and affinity, also highlighting their potential for improving BPH., (© 2024 Wiley‐VCH GmbH.)

Climate change destabilizes the symbiosis between corals and Symbiodiniaceae. The effects of ocean acidification and warming on critical aspects of coral survical such as symbiotic interactions (i.e., carbon and nitrogen assimilation and exchange) during the planula larval stage remain understudied. By combining physiological and stable isotope techniques, here we show that photosynthesis and carbon and nitrogen assimilation (H 13 CO 3 - and 15 ) in Pocillopora damicornis coral larvae is enhanced under acidification (1000 µatm) and elevated temperature (32 °C). Larvae maintain high survival and settlement rates under these treatment conditions with no observed decline in symbiont densities or signs of bleaching. Acidification and elevated temperature both enhance the net and gross photosynthesis of Symbiodiniaceae. This enhances light respiration and elevates C:N ratios within the holobiont. The increased carbon availability is primarily reflected in the 4 C enrichment of the host, indicating a greater contribution of the algal symbionts to the host metabolism. We propose that this enhanced mutualistic symbiotic nutrient cycling may bolster coral larvae's resistance to future ocean conditions. This research broadens our understanding of the early life stages of corals by emphasizing the significance of symbiotic interactions beyond those of adult corals.+ ) in Pocillopora damicornis coral larvae is enhanced under acidification (1000 µatm) and elevated temperature (32 °C). Larvae maintain high survival and settlement rates under these treatment conditions with no observed decline in symbiont densities or signs of bleaching. Acidification and elevated temperature both enhance the net and gross photosynthesis of Symbiodiniaceae. This enhances light respiration and elevates C:N ratios within the holobiont. The increased carbon availability is primarily reflected in the 13 C enrichment of the host, indicating a greater contribution of the algal symbionts to the host metabolism. We propose that this enhanced mutualistic symbiotic nutrient cycling may bolster coral larvae's resistance to future ocean conditions. This research broadens our understanding of the early life stages of corals by emphasizing the significance of symbiotic interactions beyond those of adult corals., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

In this study, a chromosome-level genome of the tropical sea cucumber Stichopus monotuberculatus was generated by a combination of Nanopore long-read, Illumina short-read, and Hi-C sequencing technologies. The final assembly was 810.54 Mb in length, with contig N50 and scaffold N50 values of 10.15 Mb and 35.36 Mb, respectively. This assembly comprised 23 pseudo-chromosomes, covering 99.82% of the genome. Completeness analysis using BUSCO indicated that 97.8% of the metazoan conserved genes were presented in their entirety. A total of 29,596 protein-coding genes were predicted, with functional annotations available for 94.43% of these genes. The high-quality genome assembly produced in this study may provide an essential foundation for future researches on resource conservation and genetic breeding of S. monotuberculatus., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

The pollution of micro- and mesoplastic (MMP) in the Eastern Indian Ocean (EIO) remains poorly understood. The present study revealed that MMP abundance in nekton from EIO in 2022 (mean: 2.30 ± 0.39 items individual -1 and 1.81 ± 0.54 items g -1 ) was significantly higher than that in 2021 (mean: 1.60 ± 0.22 items individual -1 and 0.80 ± 0.13 items g -1 ). In contrast, MMP abundance in surface water varied insignificantly between 2021 (mean: 0.04 ± 0.01 items m -3 ) and 2022 (mean: 0.05 ± 0.02 items m -3 ). The rise in predominant polymers-polypropylene (PP), rayon (RA), and polyester (PES)-in nekton from 2021 to 2022 may suggest increased pollution from face masks and home textiles along coastal regions. Notable spatial variation in PP and RA between the northeastern and southeastern regions was observed only in nekton, suggesting they are better indicators of MMP spatiotemporal variation than surface water. Shadow driftfish ingested more MMPs than purpleback flying squid and mackerel scad, likely due to its deeper habitat. By simultaneously considering color, composition, and shape, integrated MMP analysis showed insignificant correlation between MMP pollution in surface water and nekton, suggesting that nekton may ingest MMPs through multiple pathways beyond surface water. Risk indices for surface water and nekton reached moderate to upper levels globally, emphasizing the need for continued monitoring in the EIO. Epoxy resin, rubber, and PP + acrylic were identified as the most hazardous polymers, providing a valuable basis for developing effective strategies to mitigate plastic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Optical detection is frequently performed on microfluidic chips for colorimetric analysis. Integrating liquid waveguide capillaries with total internal reflection with the microfluidic chip requires less procedures, which is suitable in the optical detection of microfluidic systems and is a practical alternative to increase the optical path length in the colorimetric assay of microfluidic devices for higher sensitivities and lower detection limit. However, this alternative has not been applied to the connection of PMMA chips or the microfluidic devices for the detection of phosphate in seawater., Resluts: Here, a lab-on-a-chip system integrating a microfluidic chip and an external liquid waveguide capillary cell was presented to detect the phosphate in seawater. The detachable total internal reflection capillary made of Teflon AF 2400 connected to the chip transports sample and transmits light, greatly reducing detection limit, eliminating the interference from stray light and widening the dynamic range of the system without specific surface treatment of the microchannel. By utilizing an internal 5-cm absorption cell and an external 20-cm liquid waveguide capillary cell, the system reaches detection limits of 59 nM and 8 nM, respectively, and can detect phosphate concentration from 0 to 23 μM. An online analyzer was developed based on the high-sensitivity system and was applied to shipboard underway analysis for two scientific cruises and to laboratory measurements for seawater samples from Xisha sea area., Significance: Correlation analyses between the shipboard and laboratory phosphate measurements and other physical and biochemical elements revealed the marine ecological characteristics of the corresponding areas, demonstrating the high-sensitivity of this method over slight variations and narrow ranges of phosphate and the ability to provide microfluidic systems for high spatiotemporal resolution phosphate determination a practical and cost-effective alternative., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Although seagrass meadows are intense carbon sinks, information on the regional variability in seagrass blue carbon stocks and carbon sequestration remains limited. We estimated the organic carbon (C org ) stocks and carbon accumulation rates (CAR) of seven seagrass meadows along the subtropical coast of China's Zhanjiang City and analyzed the driving factors of variability in sediment C org stocks in three seagrass meadows. Results showed that most C org (99.83 %) was stored in the sediments, and the contribution of living biomass was minor. The average C org stocks of living biomass and sediments across all sites were 0.04 ± 0.01 and 42.03 ± 25.07 Mg C ha -1 , respectively, which were significantly lower than the world average (2.52 ± 0.48 and 194.2 Mg C ha -1 ). The sediment C org stocks of the upper 1 m ranged from 24.26 to 157.12 Mg C ha -1 with substantial variability among sites: Liusha Bay (64.93 ± 22.31 Mg C ha -1 ) > Donghai Island (33.8 ± 10.65 Mg C ha -1 ) > Dongshen Ferry (27.35 ± 4.15 Mg C ha -1 ). The average sediment CAR was 53.47 g C m -2  yr -1 , and the total CAR of 864.18 ha seagrass meadows was 260.76 ± 4.86 Mg C yr -1 in these studied sites. Physicochemical factors, such as high moisture content, salinity, CaCO 3 content, and low dry bulk density, jointly inhibited the mineralization rate of C org in sediments. Our study provides data from understudied regions to a growing dataset on seagrass carbon stocks and sequestration rates and highlights the significance of local and regional differences in seagrass blue carbon storage to accurately assess the climate change mitigation potential of seagrass ecosystems., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Xiaomei Shen reports financial support was provided by Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510,006, China. All of the authors declare that they have no conflicts of interest. This manuscript is original research, has not been previously published, and has not been submitted for publication elsewhere. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Costal eutrophication leads to increased sulfide levels in sediments, which has been identified as a major cause of the global decline in seagrass beds. The seagrass Thalassia hemprichii, a dominant tropical species in the Indo-Pacific, is facing a potential threat from sulfide, which can be easily reduced from sulfate in porewater under the influence of global climate change and eutrophication. However, its metabolic response and tolerance mechanisms to high sulfide remain unclear. Thus, the current study investigated the physiological responses and programmed metabolic networks of T. hemprichii through a three-week mesocosm experiment, integrating physiology, stable isotope, widely targeted metabolomics, transcriptomics, and microbial diversity assessments. High sulfide reduced the sediment microbial diversity, while increased sediment sulfate reduced bacterial abundance and δ 34 S. The exposure to sulfide enhanced root δ 34 S while decreased leaf δ 34 S in T. hemprichii. High sulfide was shown to inhibit photosynthesis via damaging PSII, which further reduced ATP production. In response, abundant up-regulated differentially expressed genes in energy metabolism, especially in oxidative phosphorylation, were activated to compensate high energy requirement. High sulfide also promoted autophagy by overexpressing the genes related to phagocytosis and phagolysosome. Meanwhile, metabolomic profiling revealed that the contents of many primary metabolites, such as carbohydrates and amino acids, were reduced in both leaves and roots, likely to provide more energy and synthesize stress-responsive secondary metabolites. Genes related to nitrate reduction and transportation were up-regulated to promote N uptake for sulfide detoxification. High sulfide levels specifically enhanced thiamine in roots, while increased jasmonic acid and flavonoid levels in leaves. The distinct differences in metabolism between roots and leaves might be related to sulfide levels and the growth-defense trade-off. Collectively, our work highlights the specific mechanisms underlying the response and tolerance of T. hemprichii to high sulfide, providing new insights into seagrass strategies for resisting sulfide., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this manuscript., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Due to the combined influences of marine and terrestrial disturbances, the sources of microplastics (MPs) in mangrove ecosystems are complex and diverse. Previous studies have inferred the possible involvement of mariculture activities as a potential source of mangrove MPs based on the characteristics of MPs. However, the direct contributions of mariculture-derived MPs to mangrove MPs remain largely unknown. In this study, we systematically investigated the fate of MPs in the discharge of mariculture wastewater by quantifying the source contributions of mariculture-derived MPs to rivers and mangroves. The majority of detected MPs were transparent fibers, with their composition primarily comprising materials commonly used in mariculture activities such as polyvinylpyrrolidone (PVP), polyethylene terephthalate (PET), and nylon. The partial least squares path model elucidated the relationships among the composition of MPs in ponds, rivers, and mangroves, indicating that ponds exert a substantial direct effect on mangroves, particularly significant in the sediments (63.68%). Water turbidity, sediment carbon content, and sediment particle size are key ecological factors influencing the abundance of mariculture-derived MPs. This study provides compelling evidence regarding the sources of mangrove MPs and novel insights into mitigating the dissemination of MPs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Seahorses represent the only known group of animals with male pregnancy. Seahorses have small testis that produce a limited quantity of sperm. To date, the response of this immune-privileged organ to pathogenic infections has not been reported. β-defensin (BD) is an important innate immune defence factor against pathogens in vertebrate testis. To elucidate its immunoprotection in seahorse testis, we identified the Hippocampus erectus β-defensin (HeBD) sequence in its genome via phylogenetic tree and protein-sequence structure analysis. Gene-expression analysis showed that HeBD was highly expressed in the seahorse testis and was significantly upregulated after bacterial infection, indicating that HeBD expression was related to testicular immune responses. Furthermore, antibacterial activity testing demonstrated that the mature HeBD peptide exhibited broad-spectrum aggregation activity but only moderate antibacterial activity. We found that the mature HeBD mature significantly neutralised bacterial endotoxin activity. In conclusion, our results imply that HeBD serves an immunoprotective role in seahorse testis., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that may have influenced the work reported in this study., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Intravenous albumin reduces mortality in SBP. We sought to characterize albumin use for SBP over time and investigate patient and hospital-level factors associated with use., Methods: A retrospective cohort study in the Veterans Health Administration between 2008 and 2021 evaluated trends and patient, practice-, and facility-level factors associated with use among patients with cirrhosis hospitalized for SBP confirmed with ascitic fluid criteria., Results: Among 3,871 Veterans with SBP, 803 (20.7%) did not receive albumin, 1,119 (28.9%) received albumin but not per guidelines and 1,949 (50.3%) received albumin per guidelines; use increased from 66% in 2008 to 88% in 2022. Veterans who identified as Black compared to white were less likely to receive guideline-recommended albumin (OR 0.76, 95%CI 0.59-0.98) in all analyses. Guideline-recommended albumin was more likely to be administered to Veterans with CTP class B (OR 1.39, 95% CI 1.17-1.64) and C (OR 2.21, 95% CI 1.61-3.04) compared to CTP A; and AKI Stage 1 (OR 1.48, 95%CI 1.22 -1.79), Stage 2 (OR 2.17, 95%CI 1.62-2.91), and Stage 3 (OR 1.68, 95%CI 1.18 - 2.40) compared to no AKI. GI/Hepatology consultation (OR 1.60, 95% CI 1.29--1.99), nephrology consultation (OR 1.60, 95%CI 1.23-2.07) and having both GI/hep and nephrology consultations (OR 2.17, 95%CI 1.60-2.96) were associated with higher albumin administration. In exploratory analyses accounting for interactions between model for end stage liver disease sodium (MELD-Na) and albumin, guideline-recommended albumin was associated with lower in-hospital mortality (HR 0.90, 95% CI 0.85 - 0.96)., Conclusion: Future studies should investigate optimizing albumin use for SBP to reduce variability and mitigate healthcare disparities., (Copyright © 2024 by The American College of Gastroenterology.)

The bioaccumulation and trophic transfer of pollutants in marine ecosystem members determine their ultimate ecological risks. Food web bioaccumulation models are widely used in scientific and regulatory programs to assess the bioaccumulation and ecological risks of pollutants at the ecosystem scale. The food web models are mainly established through concentration- and fugacity-based modeling approaches and include some chemical, food web-related, physiological and environmental factors. The models applied in the "forward approach" predict bioaccumulation and conduct internal exposure level-based ecological risk assessment (IEL-ERA), whereas those in the "reverse approach" are used to back-calculate the IEL-based predicted no-effect concentrations (PNECs) or environmental criteria. However, some challenges still exist in the application of food web model integrated risk assessment, including the lack of standardized/generalized frameworks, the lack of chemical- and species-specific toxicokinetic data and internal exposure (or tissue residue)-based toxicity data, and the lack of uncertainty-control methods in model estimation and parameterization. There are urgent requirements to improve models, integrate methods and update study designs in the assessment and prediction of "system-scale risks" of marine emerging organic pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Limbs are a defining characteristic of tetrapods, yet numerous taxa, primarily among amphibians and reptiles, have independently lost limbs as an adaptation to new ecological niches. To elucidate the genetic factors contributing to this convergent limb loss, we present a 12 Gb chromosome-level assembly of the Banna caecilian (Ichthyophis bannanicus), a limbless amphibian. Our comparative analysis, which includes the reconstruction of amphibian karyotype evolution, reveals constrained gene length evolution in a subset of developmental genes across three large genomes. Investigation of limb development genes uncovered the loss of Grem1 in caecilians and Tulp3 in snakes. Interestingly, caecilians and snakes share a significantly larger number of convergent degenerated conserved non-coding elements (dCNEs) than limbless lizards, which have a shorter evolutionary history of limb loss. These convergent dCNEs overlap significantly with active genomic regions during mouse limb development and are conserved in limbed species, suggesting their essential role in limb patterning in the tetrapod common ancestor. While most convergent dCNEs emerged in the jawed vertebrate ancestor, coinciding with the origin of paired appendage, more recent dCNEs also contribute to limb development, as demonstrated through functional experiments. Our study provides novel insights into the regulatory elements associated with limb development and loss, offering an evolutionary perspective on the genetic basis of morphological specialization., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

While the tropical Pacific teleconnection to North America has been studied extensively, the impact of the Indian Ocean on North American climate has received less attention. Here, through observational analysis and hierarchy atmospheric model simulations with different complexity, we find that the Indian Ocean plays a crucial role in North American winter climate through a teleconnection termed the Indian Ocean - North America pattern. We show that in the warm Indian Ocean phase, this teleconnection contributes to anomalously cold winters along the west coast of the United States through advection with increased mountain snowfall, while simultaneously leading to warmer conditions over the Great Lakes region. Snow-albedo feedback amplifies these Rossby wave-induced surface anomalies. Remarkably, this teleconnection pattern is at work on both interannual and multi-decadal time scales, with its climatic impact being slightly less pronounced than that induced by tropical Pacific sea surface temperature anomalies. Our findings underscore the significance of the Indian Ocean in both the prediction and future projection of North American climate., (© 2024. The Author(s).)

Mollusca, the second-most diverse animal phylum, is estimated to have over 100,000 living species with great genetic and phenotypic diversity, a rich fossil record, and a considerable evolutionary significance. Early work on molluscan systematics was grounded in morphological and anatomical studies. With the transition from oligo gene Sanger sequencing to cutting-edge genomic sequencing technologies, molecular data has been increasingly utilised, providing abundant information for reconstructing the molluscan phylogenetic tree. However, relationships among and within most major lineages of Mollusca have long been contentious, often due to limited genetic markers, insufficient taxon sampling and phylogenetic conflict. Fortunately, remarkable progress in molluscan systematics has been made in recent years, which has shed light on how major molluscan groups have evolved. In this review of molluscan systematics, we first synthesise the current understanding of the molluscan Tree of Life at higher taxonomic levels. We then discuss how micromolluscs, which have adult individuals with a body size smaller than 5 mm, offer unique insights into Mollusca's vast diversity and deep phylogeny. Despite recent advancements, our knowledge of molluscan systematics and phylogeny still needs refinement. Further advancements in molluscan systematics will arise from integrating comprehensive data sets, including genome-scale data, exceptional fossils, and digital morphological data (including internal structures). Enhanced access to these data sets, combined with increased collaboration among morphologists, palaeontologists, evolutionary developmental biologists, and molecular phylogeneticists, will significantly advance this field., (© 2024 Cambridge Philosophical Society.)

Few aerobic hyperthermophilic microorganisms degrade polysaccharides. Here, we describe the genome-enabled enrichment and optical tweezer-based isolation of an aerobic polysaccharide-degrading hyperthermophile, Fervidibacter sacchari, previously ascribed to candidate phylum Fervidibacteria. F. sacchari uses polysaccharides and monosaccharides for growth at 65-87.5 °C and expresses 191 carbohydrate-active enzymes (CAZymes) according to RNA-Seq and proteomics, including 31 with unusual glycoside hydrolase domains (GH109, GH177, GH179). Fluorescence in-situ hybridization and nanoscale secondary ion mass spectrometry confirmed rapid assimilation of 13 C-starch in spring sediments. Purified GHs were optimally active at 80-100 °C on ten different polysaccharides. Finally, we propose reassigning Fervidibacteria as a class within phylum Armatimonadota, along with 18 other species, and show that a high number and diversity of CAZymes is a hallmark of the phylum, in both aerobic and anaerobic lineages. Our study establishes Fervidibacteria as hyperthermophilic polysaccharide degraders in terrestrial geothermal springs and suggests a broad role for Armatimonadota in polysaccharide catabolism., (© 2024. The Author(s).)

The photosynthetic microorganisms within the coral holobiont produce energy and organic compounds through photosynthesis, which are vital for the biocalcification and heat tolerance of coral hosts. However, aerobic anoxygenic phototrophic bacteria (AAPB), which are one of the most important photosynthetic microorganisms, have not been thoroughly investigated in this environment. In this study, a novel AAPB, SCSIO 66989 T , was isolated from the reef-building coral Favia sp. and considered a beneficial microorganism for corals (BMC). The polyphasic taxonomic analysis showed that it had the highest similarities with Parasphingorhabdus litoris DSM 22379 T (95.9%) and Altererythrobacter ishigakiensis ATCC BAA-2084 T (95.7%). Phylogenetic analysis showed that it formed an independent clade, distinguishing it from other genera within the family Sphingomonadaceae . The predominant fatty acids were C 18 : 1  ω7 c and/or C 18 : 1  ω6 and the type strains of 16 : 0 . The major respiratory quinone was ubiquinone-10 (Q-10). Sphingolipid, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine were the diagnostic polar lipids. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between SCSIO 66989 T and the type strains of P. litoris DSM 22379 T and A. ishigakiensis represents a new species of a novel genus in the family T were 69.2-70.0%, 58.6-61.2% and 19.2-19.7%, respectively. These results indicate that strain SCSIO 66989 T represents a new species of a novel genus in the family Sphingomonadaceae , for which the name Alterisphingorhabdus coralli gen. nov. sp. nov. is proposed.

Global climate change is exacerbating biological invasions; however, the roles of genomic and epigenomic variations and their interactions in future climate adaptation remain underexplored. Using the model invasive ascidian Botryllus schlosseri across the Northern Hemisphere, we investigated genomic and epigenomic responses to future climates and developed a framework to assess future invasion risks. We employed generalized dissimilarity modeling and gradient forest analyses to assess genomic and epigenomic offsets under climate change. Our results showed that populations with genomic maladaptation did not geographically overlap with those experiencing epigenomic maladaptation, suggesting that genomic and epigenomic variations play complementary roles in adaptation to future climate conditions. By integrating genomic and epigenomic offsets into the genome-epigenomic index, we predicted that populations with lower index values were less maladapted, indicating a higher risk of future invasions. Native populations exhibited lower offsets than invasive populations, suggesting greater adaptive potentials and higher invasion risks under future climate change scenarios. These results highlight the importance of incorporating multi-omics data into predictive models to study future climate (mal)adaptation and assess invasion risks under global climate change., (© 2024 John Wiley & Sons Ltd.)

As a group of emerging contaminants of global concern, tire additives and their transformation products (TATPs) are causing a severe threat to aquatic ecosystems, particularly the highly lethal effects of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) on certain fish species. Yet, the contamination status of TATPs in the lake ecosystems remains largely uncharacterized. This study conducted the first nationwide monitoring of the distribution characteristics of TATPs in 208 lake sediments collected from five lake regions across China. All the 13 TATPs were identified in lake sediments, with the total levels varying between 1.4 and 1355 ng/g, and 4-hydroxydiphenylamine (4-OH-PPD) as the most dominant. The total levels of TATPs decreased in the following order: Yunnan-Guizhou Plateau > Inner Mongolia-Xinjiang Region, Eastern Plain > Qinghai-Tibet Plateau, and Northeast Plain (p < 0.05). The geographical distribution of TATPs in lake sediments was significantly driven by total organic carbon content, temperature, and population density. N,N'-di-2-naphthyl-p-phenylenediamine, 6PPD-Q, N,N'-diphenyl-p-phenylenediamine, and 4-OH-PPD belonged to high-priority contaminants. Our study emphasizes that emerging pollutant TATPs place significant pressure on lake ecosystems and deserve urgent attention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Seven novel linear polyketides, talaketides A-G (1-7), were isolated from the rice media cultures of the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41027. Among these, talaketides A-E (1-5) represented unprecedented unsaturated linear polyketides with an epoxy ring structure. The structures, including absolute configurations of these compounds, were elucidated through detailed analyses of nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HR-MS) data, as well as electronic custom distributors (ECD) calculations. In the cytotoxicity screening against prostate cancer cell lines, talaketide E (5) demonstrated a dose-dependent inhibitory effect on prostate cancer PC-3 cell lines, with an IC 50 value of 14.44 μmol·L -1 . Moreover, compound 5 significantly inhibited the cloning formation of PC-3 cell lines and arrested the cell cycle in S-phase, ultimately inducing apoptosis. These findings indicate that compound 5 may serve as a promising lead compound for the development of a potential treatment for prostate cancer., (Copyright © 2024 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

Dynamics of phytoplankton in coastal waters is a function of nutrient influx and the present study investigated the trend in nutrient dynamics and phytoplankton abundance of Daya Bay (DB), South China Sea, from 1986 to 2020. Dissolved inorganic nitrogen (DIN), Dissolved inorganic phosphate (DIP) and Silicates were measured. DIN concentration exhibited an increasing trend over the last decades, and it was above the threshold for the phytoplankton growth. DIP level showed a significant decreasing trend throughout the studied period, falling below the threshold for phytoplankton growth in the last decade, where harmful algal blooms were dominated by the dinoflagellates. Long-term anthropogenic influences severely change influx of DIN, DIP, and silicates which in turn shape the architecture of phytoplankton communities. Thus, the understanding of the complex interaction between nutrient influx, anthropogenic activities and dynamics of both water quality and biological elements are particularly important to decide criteria to manage coastal ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microorganisms in the sediment play a pivotal role in the functioning and stability of seagrass ecosystems and their dynamics are influenced by the nutrient acquisition strategies of host plants. While the distinct impacts of microbial generalists and specialists on community dynamics are recognized, their distribution patterns and ecological roles within seagrass ecosystems remain largely unexplored. To address this issue, we conducted an analysis of community assembly processes and co-occurrence relationships of both microbial generalists and specialists within sediment profiles (0-100 cm) from seagrass habitats subjected to differing land use conditions. The results revealed that seagrasses in Yifeng Estuary experienced the large proportion of cultivated land and exhibited higher organic carbon content in the 0-20 cm surface sediment layer. Nitrogen-cycling bacteria were predominantly associated with seagrasses from Yifeng Estuary, whereas Vibrio spp. was more prevalent in seagrasses from Liusha Bay. Notably, seagrass Halophia beccarii (YHB) in Yifeng Estuary harbored higher niche breadths for both microbial generalist and specialist compared to Halodule uninervis (LHU) and Halophia ovalis (LHO) from Liusha Bay. Stochastic processes were pivotal in shaping seagrass sediment microbial communities, with a higher immigration rate observed in YHB, suggesting greater microbial turnover in this area. Additionally, YHB sediment presented lower drift and higher dispersal limitation among generalists compared to LHU and LHO, whereas the pattern was reversed among specialists. Specialists were found to play a crucial role in shaping microbial interactions within YHB sediment, with genera Halioglobus identified as keystone species in the network. The specialists were further found to significantly influence microbial β-diversity in seagrass sediment directly. Overall, our findings illustrated how microbial generalists and specialists were distributed in seagrass sediments in response to land use changes and provided new insights into the potential roles of microbial regulation in degraded seagrass ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed to understand the sources and transport mechanism of organic matter (OM) in the Ganges-Brahmaputra-Meghna (GBM) river system in Bangladesh. We conducted analyses of total organic carbon (TOC), total nitrogen (TN), their stable isotopes (δ 13 C and δ 15 N), and sediment grain size. The results reveal a heterogeneous mixture of OM derived from terrestrial plants, aquatic environments, and anthropogenic sources. The Brahmaputra River exhibited higher concentrations of TOC and TN, with δ 13 C and δ 15 N values indicating that the OM is primarily sourced from C 3 plants. Conversely, the Ganges River demonstrated lower TOC levels and higher isotopic values, reflecting significant anthropogenic inputs. The Lower Meghna showed a mixture of terrestrial and marine sources. Variations in the TOC/TN ratios across the river system underscore the complex interplay between natural and anthropogenic factors. Additionally, sediment grain size plays a crucial role, with finer sediments in the Brahmaputra River associated with increased OM concentrations, while coarser sediments in the Ganges River correlate with lower TOC and TN levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Marine mussels inhabit a wide range of ocean depths, necessitating unique adaptations to cope with varying hydrostatic pressures. This study investigates the transcriptomic responses and evolutionary adaptations of the deep-sea mussel Gigantidas platifrons and the shallow-water mussel Mytilus galloprovincialis to high hydrostatic pressure (HHP) conditions. By exposing atmospheric pressure (AP) acclimated G. platifrons and M. galloprovincialis to HHP, we aim to simulate extreme environmental challenges and assess their adaptive mechanisms. Through comparative transcriptomic analysis, we identified both conserved and species-specific mechanisms of adaptation, with a notable change in gene expression associated with immune system, substance transport, protein ubiquitination, apoptosis, lipid metabolism and antioxidant processes in both species. G. platifrons demonstrated an augmented lipid metabolism, whereas M. galloprovincialis exhibited a dampened immune function. Additionally, the expressed pattern of deep-sea mussel G. platifrons were more consistent than shallow-water mussel M. galloprovincialis under hydrostatic pressures changed conditions which corresponding the long-term living stable deep-sea environment. Moreover, evolutionary analysis pinpointed positively selected genes in G. platifrons that are linked to transmembrane transporters, DNA repair and replication, apoptosis, ubiquitination which are important to cell structural integrity, substances transport, and cellular growth regulation. This indicates a specialized adaptation strategy in G. platifrons to cope with the persistent HHP conditions of the deep sea. These results offer significant insights into the molecular underpinnings of mussel adaptation to varied hydrostatic conditions and enhance our comprehension of the evolutionary forces driving their depth-specific adaptations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Twelve compounds, including eleven bisabolane-type sesquiterpenoids ( 1  -  11 ), and one bacillibactin ( 12 ) were identified from marine-derived fungus Aspergillus sydowii SCSIO 41041 isolated from Creseis acicula . The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Biologically, all compounds were evaluated for their acetyl cholin-esterase (AChE) enzyme, pancreatic lipase (PL) enzyme, neuraminidase (NA) and phosphodiesterase 4 (PDE4) inhibitory activities. Compound 12 displayed significant inhibitory activity against neuraminidase (NA) with an IC 50 value of 24.0 μM, which was equivalent to the positive drug oseltamivir phosphate (IC 50 value of 20.0 μM). And the NA inhibitory activity was confirmed by molecular docking analysis.

Actinobacterial species are mostly thought to be nonmotile. Recent studies have revealed the degenerate evolution of flagella in this phylum and different flagellar rod compositions from the classical model. Moreover, flagella-independent motility by various means has been reported in Streptomyces spp. and Mycobacterium spp., but the underlying mechanisms remain elusive., Competing Interests: Declaration of interests None are declared., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Understanding patterns of biodiversity change is essential as coral reefs experience recurrent cycles of disturbance and recovery. Shifts in the total cover and species composition of habitat-forming corals can have far-reaching consequences, including shifts in coral functional traits and impacts on local fish assemblages. We surveyed coral and fish assemblages along the southern coast of Hainan Island near Sanya, China, in 2006, 2010, and 2018, during a period with repeated mass bleaching events. We showed that coral biodiversity in this region is in a state of flux, with losses and gains in coral cover and an increase in species richness over time. Despite increasing species diversity, the region suffered a loss of coral trait diversity by 2010, with an incomplete recovery by 2018, owing to declines in species with key habitat-forming traits (e.g., high surface areas and fractal structure) such as corymbose corals. Concurrently, there was an increase in functional redundancy due to the proliferation of the dominant encrusting and massive corals. Coral cover was positively associated with the abundance of reef fish, indicating that the changes observed in coral abundance can impact reef-associated species. These results demonstrate that the slow recovery of coral biodiversity in southern Hainan Island has been hampered by the loss of specific coral traits and highlight the importance of protecting vulnerable coral traits in conservation and management strategies., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

Microorganisms are significant drivers of organic matter mineralization and are essential in marine biogeochemical cycles. However, the variations and influencing factors in prokaryotic communities from cold-seep sediments to the water column and the specific role of these microorganisms in biogeochemical cycles in the water column above cold seep remain unclear. Here, we investigated prokaryotic communities and their roles in nitrogen/sulfur cycling processes and conducted in situ dissolved organic matter (DOM) enrichment experiments to explore the effects of diverse sources of DOM on prokaryotic communities. Field investigations showed that the prokaryotic communities in the near-bottom water were more similar to those in the deep layer of the euphotic zone (44.60%) and at a depth of 400 m (50.89%) than those in the sediment (18.00%). DOM enrichment experiments revealed that adding dissolved organic nitrogen (DON) and phosphorus DOP caused a notable increase in the relative abundances of Rhodobacterales and Vibrionales, respectively. A remarkable increase was observed in the relative abundance of Alteromonadales and Pseudomonadales after the addition of dissolved organic sulfur (DOS). The metagenomic results revealed that Proteobacteria served as the keystone taxa in mediating the biogeochemical cycles of nitrogen, phosphorus, and sulfur in the Haima cold seep. This study highlights the responses of prokaryotes to DOM with different components and the microbially driven elemental cycles in cold seeps, providing a foundational reference for further studies on material energy metabolism and the coupled cycling of essential elements mediated by deep-sea microorganisms., Importance: Deep-sea cold seeps are among the most productive ecosystems, sustaining unique fauna and microbial communities through the release of methane and other hydrocarbons. Our study revealed that the influence of seepage fluid on the prokaryotic community in the water column is surprisingly limited, which challenges conventional views regarding the impact of seepage fluids. In addition, we identified that different DOM compositions play a crucial role in shaping the prokaryotic community composition, providing new insights into the factors driving microbial diversity in cold seeps. Furthermore, the study highlighted Proteobacteria as key and multifaceted drivers of biogeochemical cycles in cold seeps, emphasizing their significant contribution to complex interactions and processes. These findings offer a fresh perspective on the dynamics of cold-seep environments and their microbial communities, advancing our understanding of the biogeochemical functions in deep-sea environments., Competing Interests: The authors declare no conflict of interest.

Multistage plate subduction plays a crucial role in magmatism; however, the mechanisms by which deep geodynamic processes govern volcanism in the Alaska subduction zone remain controversial. Using numerous travel-time data from several seismic arrays, we constructed high-resolution tomographic models to investigate the velocity structure of the Pacific Plate and Yakutat slab. Our tomographic results revealed high-velocity anomalies in the Pacific Plate and Yakutat slab, while the low-velocity areas within the Pacific Plate were identified as slab tears. We suggest that the Pacific Plate transitioned from oblique subduction along the Aleutian volcano chain to lower-angle subduction beneath the Pacific-Yakutat Plate interaction zone, forming two slab tears that enhance hot asthenosphere materials upwelling. The partial melting of the mantle wedge induced by Pacific slab dehydration and the concurrent upwelling of mantle materials jointly drove volcanism in the transition zone. Conversely, the flat subduction of the Yakutat slab into the mantle wedge overlying the Pacific slab effectively hindered the upwelling of hot hybrid materials, cooling the Pacific mantle wedge. These results offer a new perspective on the influence of slab dynamics on volcanic and magmatic processes in the region and represent an advancement in our understanding compared to previous studies, which did not resolve the tears within the slab or their geodynamic implications at this level of detail., (© 2024. The Author(s).)