Deep-Sea Research Part I-Oceanographic Research Papers最新文献

{"title":"Quantifying the contribution of modern Asian dust to the southern Yap trench and its southeastern region","authors":"Xiaoqiang Guo ,&nbsp;Yanyan Zhao ,&nbsp;Zhishun Zhang ,&nbsp;Guangyao Cao ,&nbsp;Lei Yang ,&nbsp;Guanglu Zhang ,&nbsp;Jishang Xu ,&nbsp;Guangxue Li ,&nbsp;Sanzhong Li","doi":"10.1016/j.dsr.2025.104464","DOIUrl":"10.1016/j.dsr.2025.104464","url":null,"abstract":"<div><div>Dust plays a vital role in the Earth system, yet its contribution to the tropical West Pacific is still under-quantified. This gap limits the ability to assess the impacts of dust on the biogeochemical cycles in this region. In this study, we analyzed grain size distribution, the contents of major and trace elements in lithogenic components isolated by sequential leaching and in three grain-size fractions of surface sediments from the southern Yap Trench and its southeastern region in the tropical West Pacific, along with the characteristics of the climatological surface and subsurface current fields. Our results initially identified that the provenances of lithogenic components comprise not only Asian dust and volcanic material but also continental material from northern New Guinea rivers. Furthermore, the Rare Earth Elements-based dust fractions within the lithogenic components, derived from a binary mixing model and correction formula, range from 0.08 to 0.70, with an average of 0.39. This is highly consistent with the ⁸⁷Sr/⁸⁶Sr-based results and ratios of illite to smectite. In bulk sediment samples, the dust contents vary from 0.82% to 49.42%, with an average of 18.82%. Spatially, dust is enriched in the southern Yap Trench, West Caroline Basin, and Sorol Trough, while it was depleted on the West Caroline Ridge. This pattern may result from the potential redistribution induced by bottom current and/or dilution effect of authigenic smectite and carbonate on the West Caroline Ridge. Ultimately, although traditional geochemical methods and diagrams comparing illite/kaolinite and kaolinite/chlorite ratios, corrected for fluvial input, proved insufficient in distinguishing dust source regions and relevant transport media, dust aerosol analysis based on the MERRA-2 database suggests contributions from both Central Asian and East Asian deserts, with the former potentially playing a more prominent role. However, further studies are required to validate the aerosol-based method and these implications, as they are essential for reconstructing paleoatmospheric circulation from paleodust records. Hopefully, this study would contribute to a more comprehensive understanding of the global dust cycle and its interplay with biogeochemical cycles in abyssal trenches and basins.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"218 ","pages":"Article 104464"},"PeriodicalIF":2.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ecopath modelling Unravels the food web of the Gulf of Corinth, a deep Mediterranean important marine Mammal area","authors":"Nikolaos Raptis ,&nbsp;Georgia Papantoniou ,&nbsp;Dionysios E. Raitsos ,&nbsp;Dimitrios Damalas ,&nbsp;Konstantinos Tsagarakis","doi":"10.1016/j.dsr.2025.104466","DOIUrl":"10.1016/j.dsr.2025.104466","url":null,"abstract":"<div><div>The Mediterranean Sea, recognized as a biodiversity hotspot, is facing significant impacts from human-induced stressors such as overfishing and climate change, which exert pressure on its ecosystems. The Gulf of Corinth (eastern Mediterranean Sea, Greece) encompasses a deep ecosystem that has not been extensively studied, despite its rich biodiversity and the presence of Protected, Endangered, and Threatened (PET) species. An Ecopath trophic model was implemented for the baseline period 2014–2016 to outline its ecological structure, with special emphasis on (i) dolphins (bottlenose, striped, and common) and other PET species, as the Gulf is an Important Marine Mammal Area; (ii) deep-living groups such as mesopelagic fishes, due to their wide distribution and high abundance; and (iii) commercial species to assess the impact of fishing. Model outputs reveal a complex food web structure with numerous links among functional groups, with detritus serving as dominating energy source, particularly in the pelagic zone. Dominant species, such as mesozooplankton, and keystone species, including squid, sharks, and hake, shape the trophic relationships in the water column, with keystone prey groups such as shrimps and mesopelagic fish contributing significantly. Model statistics align with those of other modeled ecosystems in Greece, consistent with productivity patterns and other ecological features; however, ecological indicators suggest a relatively immature ecosystem state despite low fishing pressure. Due to spatio-temporal bans on semi-industrial fisheries and the absence of extensive suitable trawling grounds and small pelagic fish populations, small-scale fisheries exert the highest fishing pressure. The estimated probability of sustainable fisheries in the ecosystem is high (estimated at 94%), while trophic competition among fisheries and PET species is moderate to low, with the exception of bottlenose dolphins. The model was developed to enhance understanding of species trophic relationships and energy flows in the system, making it a critical tool for effective management and conservation initiatives in the Gulf of Corinth.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"218 ","pages":"Article 104466"},"PeriodicalIF":2.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abundant taxa can better indicate seasonal and depth variations of pelagic microbial communities in the tropical open ocean","authors":"Dong Sun ,&nbsp;Qianwen Shao ,&nbsp;Yunzhi Feng ,&nbsp;Chunsheng Wang","doi":"10.1016/j.dsr.2025.104463","DOIUrl":"10.1016/j.dsr.2025.104463","url":null,"abstract":"<div><div>Understanding seasonal and depth variations of microbial communities is essential to predict the impact of climate change on pelagic ecosystem. Unfortunately, a major barrier to this knowledge is that long-term deployed automated equipment meets the low-cost requirement for obtaining time-series data in pelagic oceans far from land, but these techniques hardly obtain diversity data covering the whole community. To test whether monitoring abundant taxa can better capture variations of pelagic microbial communities in the tropical open ocean, the seasonal and depth variations of prokaryotic and microeukaryotic communities throughout the water column over three seasons were studied using 16S rRNA and 18S rRNA gene amplicon sequencing in the western Pacific Warm Pool, where is the most stable open ocean marine environment on earth. Our results showed that photic and aphotic layers were comprised of distinct microbes, and seasonal changes of microbes occurred at all depths, which were strongest at 200 m. Specificity and occupancy indicated that most of seasonal or depth specialists were abundant taxa. The community similarity distributions of abundant taxa and the whole microbial community were similar, while that of rare taxa was completely different. These results suggested abundant taxa can better indicate seasonal and depth variations of pelagic microbial communities compared to rare taxa, which provide a basis for the future development of autonomous platforms for long time-series monitoring of microbial community dynamics using a minimal number of taxa.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"218 ","pages":"Article 104463"},"PeriodicalIF":2.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential carbon sources and sinks in frontal zones dominated respectively by mesoscale and submesoscale processes in the Luzon Strait","authors":"Sihai Liu ,&nbsp;Qibin Lao ,&nbsp;Guangzhe Jin ,&nbsp;Shuwen Zhang ,&nbsp;Chunqing Chen ,&nbsp;Shangjun Cai ,&nbsp;Fajin Chen","doi":"10.1016/j.dsr.2025.104461","DOIUrl":"10.1016/j.dsr.2025.104461","url":null,"abstract":"<div><div>The Luzon Strait experiences active ocean fronts resulting from the intrusion of the Kuroshio water, accompanied by substantial mesoscale and submesoscale processes. These processes induce variable patterns of upwelling and downwelling where submesoscale dynamics are often more intense than their mesoscale counterparts, profoundly affecting phytoplankton production and sedimentation. However, the ultimate role of these processes in the production and export of carbon remains unclear. We analyzed daily satellite and reanalysis data from 1999 to 2019, revealing the climatological patterns and spatial variations of mesoscale and submesoscale processes during both summer and winter, thereby identifying distinct frontal zones dominated by either mesoscale or submesoscale processes. Our results show that the cyclonic front area on the eastern side of the strait and anticyclonic front area along the Kuroshio axis, are significantly influenced by submesoscale processes. These areas are identified as potential carbon sinks due to enhanced nutrient availability and elevated sedimentation rates. Conversely, although mesoscale fronts contribute more significantly to Chlorophyll-<em>a</em>, the cyclonic front area on the western side of the strait, dominated by mesoscale processes, serves as a potential carbon source. This difference is attributed to the slower sedimentation rate of organic matter in the mesoscale region, which prolongs the decomposition of both <em>in-situ</em> and horizontally transported matter. These findings deepen our understanding of the impacts of mesoscale and submesoscale processes within frontal zones on the global carbon cycle.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"217 ","pages":"Article 104461"},"PeriodicalIF":2.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marine porewater dissolved organic matter linked to the paleoclimate and archaeal communities on glacial-interglacial timescales","authors":"Minchun Li ,&nbsp;Wei Xie ,&nbsp;Xizheng Lin ,&nbsp;Chuanlun Zhang ,&nbsp;Kedong Yin","doi":"10.1016/j.dsr.2025.104460","DOIUrl":"10.1016/j.dsr.2025.104460","url":null,"abstract":"<div><div>Although dissolved organic matter (DOM) in marine sediments is one of the most important carbon reservoirs, its distribution, characterization, and associated biogeochemical processes in marine sediments have not been fully investigated, especially in the deep ocean. In this study, we sampled a deep-sea gravity core from the northern South China Sea (SCS) to investigate the characterization and distribution of porewater DOM, which is the most dynamic part of the sedimentary DOM pool, as well as its correlations with other environmental components in sediments during glacial-interglacial cycles. The gravity core covers a period from Marine Isotope Stage (MIS) 3 to Holocene. Overall, the fluorescence intensity of porewater DOM increased with depth along the core expect the sample belonging to MIS 2, indicating the accumulation of fluorescence DOM (FDOM) with geological age. The abnormally high value of FDOM intensity occurred in MIS 2, which might be attributed to the enhanced marine primary productivity and favorable preservation conditions during this glacial period. Despite a longer degradation time since MIS 3, the molecular weight (MW) of porewater DOM remained relative constant among all stages. Compared to MIS 1, higher paleo-productivity and stronger upper marine mixing in MIS 3 may be responsible for this relatively constancy in MW, leading to an increase in marine autochthonous labile DOM with high MW. The composition of the sedimentary archaeal communities as well as archaeal functions were significantly different between MIS 1 and MIS 3. These differences implied that there were variations in DOM-microbe interactions along the core, thus could influence the vertical profile of porewater DOM. The findings in this study elucidate the close connection between porewater DOM and geological events as well as microbial communities in deep-sea sediments.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"217 ","pages":"Article 104460"},"PeriodicalIF":2.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissolved selenium in the Northeastern Indian Ocean","authors":"Jing Zhang ,&nbsp;Wan Wan Cao ,&nbsp;Yan Chang ,&nbsp;Wei Zheng ,&nbsp;Shuo Jiang ,&nbsp;Jie Jin","doi":"10.1016/j.dsr.2025.104459","DOIUrl":"10.1016/j.dsr.2025.104459","url":null,"abstract":"<div><div>Selenium is considered as one of essential micronutrients in marine ecosystems, and is involved in a number of enzymatic reactions, and hence plays an important role in various metabolic pathways. However, the biogeochemistry of selenium in the ocean is still poorly described in the literature because of lack of observational data. In this study, we reported the concentration and chemical speciation of dissolved selenium in the Eastern Indian Ocean (EIO) based on observations and sample analyses made in 2017 and 2018. In surface waters, concentration of Se(IV), Se(VI) are all low relative to dissolved organic selenium (DOSe), being related to the biological uptake in the euphotic zone. The regeneration of Se in the mesopelagic waters induces that concentration increases with depth for inorganic fraction of dissolved pool, with a systematic change in species ratio, indicating active transformations there. In the deep part of vertical profiles, spatial structure of Se shows a similar trend with dissolved oxygen (DO) and is consistent to the pattern of deep water circulation.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"217 ","pages":"Article 104459"},"PeriodicalIF":2.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin and propagation of M2 internal tides in the Arabian Sea","authors":"Hua Zheng ,&nbsp;Min Wang ,&nbsp;Tao Zhang ,&nbsp;Ruibin Ding ,&nbsp;Ying Jin ,&nbsp;Kun Zhang ,&nbsp;Deng Zhang ,&nbsp;Binjie Wu ,&nbsp;Yiwei Zhang","doi":"10.1016/j.dsr.2024.104441","DOIUrl":"10.1016/j.dsr.2024.104441","url":null,"abstract":"<div><div>Internal tides (ITs) generated by the interaction of barotropic tides and rough topography in stratified oceans play a significant role in turbulent mixing and thermohaline circulation. The baroclinic modes, propagation, energy, and origin of M₂ ITs in the Arabian Sea are analyzed using Multivariate Inversion of Ocean Surface Topography Internal Tide Model product (MIOST-IT). The M₂ ITs are generated in the northeast Arabian Sea, around the Socotra Island, and around the Maldive Islands, dominated by the mode-1 component with a wavelength of approximately 110 km. The most energetic M₂ ITs radiate from the continental shelf of the northeast Arabian Sea for more than one thousand kilometers with mode-1 and mode-2 energy of approximately 0.56 GW and 0.04 GW, respectively. M₂ ITs generated around the ridges southeast of the Gulf of Oman propagate southeastward, whereas they radiate in all directions from the Socotra Island. The northeastward-propagated M₂ ITs from the Socotra Island and the southwestward-propagated M₂ ITs from the continental shelf form standing waves. The M₂ ITs propagate westward on the western side of the Maldive Islands and eastward on the eastern side, dominated by mode-1 with energy of 0.17 GW and 0.08 GW, respectively. The study presents the characteristics of multi-directionally propagated and multi-modally M₂ ITs in the Arabian Sea, which addresses the characteristics of M₂ ITs in the region, therefore contributing to the understanding of the Arabian Sea's role in regional and global overturning circulation, energy budget, climate dynamics, and ecological environments.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"216 ","pages":"Article 104441"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pteropod assemblages in the oceanic waters of the southern Gulf of Mexico (June 2015)","authors":"H.S. López-Arellanes ,&nbsp;J.A. Cruz-Barraza ,&nbsp;E.D. Ruvalcaba-Aroche ,&nbsp;C.A. Silva-Segundo","doi":"10.1016/j.dsr.2024.104431","DOIUrl":"10.1016/j.dsr.2024.104431","url":null,"abstract":"<div><div>The pteropod community structure in the oceanic waters of the southern Gulf of Mexico (sGoM) was analyzed in June 2015. For the first time, we used an integrative morphological and molecular approach for pteropod identification in the sGoM. A total of 32 pteropod taxa were morphologically identified from the oceanic waters of which 12 were successfully sequenced, at least for one of the loci implemented (COI and 28S). The molecular data support the taxonomic identity of half of them. However, despite the morphological differences in the other six taxa, the molecular evidence displayed low genetic variability, resulting in a resolution to the genus level. During the sampling campaign, the oceanographic conditions were very homogeneous in all the sampled areas, with high surface temperatures (SST &gt;27.5 °C) and low chlorophyll (CHL &lt;0.5) concentrations. Nevertheless, CHL presented a positive and significant correlation with total pteropod abundance, herbivores abundance and carnivores abundance, suggesting a bottom-up control of the pteropod community. The ecological analysis showed that four species accounted for 63% of the pteropod abundance: <em>Heliconoides inflatus</em>, <em>Creseis conica</em>, <em>Limacina trochiformis</em> and <em>Creseis acicula</em>. The cluster analysis showed the presence of four assemblages, named after their distribution and species composition. The oceanic assemblage presented a wide distribution over the sampled area, characterized by a set of oceanic species such as <em>H. inflatus</em>, <em>Styliola subula</em> and <em>Limacina lesueurii</em>, with no apparent correlation with the measured environmental variables. The coastal oceanic assemblage presented the highest pteropod abundances; it was characterized by the dominance of the neritic species <em>C. conica</em> and <em>L. trochiformis</em>, and significant positive correlation with CHL concentration. The other two assemblages were distributed in the vicinity of an anticyclonic eddy with high stratification and low CHL values in the northwest, and presented a mixed dominance among the oceanic species <em>H. inflatus</em>, <em>C. acicula</em> and <em>S. subula</em>. The oceanic assemblage is suggested as the basal pteropod community in the sGoM. It is modified by the deflection of the coastal current in the southeast that transports nutrients and biota into the oceanic domain and produce relative enrichment of the CHL concentration. The presence of a Loop Current anticyclonic eddy in the northwest, increases the stratification and accentuates the oligotrophic conditions, leading to a different pteropod community well adapted to those oligotrophic conditions.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"216 ","pages":"Article 104431"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bathymetric distribution of abyssal and hadal amphipod families and genera in the Japan Trench and the southernmost Kuril-Kamchatka trench","authors":"Daiki Yamamoto,&nbsp;Takuya Yahagi,&nbsp;Shigeaki Kojima","doi":"10.1016/j.dsr.2024.104438","DOIUrl":"10.1016/j.dsr.2024.104438","url":null,"abstract":"<div><div>Amphipoda, belonging to superorder Peracarida, represents a conspicuous proportion of benthic fauna occurring across multiple depth zones. Extensive sampling has been conducted to understand the composition and distribution of benthic organisms, particularly in the Northwest Pacific. However, logistical challenges and limited opportunities have restricted our understanding of benthic fauna diversity and distribution. Using two types of trawls and an epibenthic sledge, abyssal and hadal benthic fauna were collected across 55 sampling sites from both the Japan Trench and the Kuril-Kamchatka Trench, at depths between 3689 m and 8010 m. A collection of 3126 deep-sea amphipods was obtained and the animals were assigned to at least 76 genera belonging to 37 families during the two expeditions. The most abundant family was Phoxocephalidae, followed by Ampeliscidae, Lysianassoidea and Oedicerotidae in descending order of abundance. In addition, high numbers of genera of the Pardaliscidae, Oedicerotidae, Stegocephalidae and Synopiidae families were identified. In the two trenches, the number of genera showed a weak inverse correlation with depth at both abyssal and hadal depths. Amphipod diversity and abundance were highest in the landward slopes, whereas those observed in the trench axes were the least diverse and abundant. High productivity, in addition to proximity to the Japanese archipelago, may explain the amphipod assemblage characteristics observed in our study areas. Our findings present novel data on the global depth records for eight identified and one unidentified amphipod genera, belonging to nine families.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"216 ","pages":"Article 104438"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Descriptions of two new deep-sea nemertean species from the genera Alvinonemertes and Sagornya gen. nov. (Hoplonemertea, Oerstediina) with discussion on close genetic relationship between deep-sea species","authors":"Alexei V. Chernyshev,&nbsp;Vasiliy G. Kuznetsov","doi":"10.1016/j.dsr.2024.104439","DOIUrl":"10.1016/j.dsr.2024.104439","url":null,"abstract":"<div><div>In a recent study by Sagorny et al. (2022), nine new species of deep-sea hoplonemerteans, including five from the new genus <em>Alvinonemertes</em> Sagorny, von Döhren, Rouse &amp; Tilic, 2022, have been described from off the Pacific coast of Costa Rica and the Oregon margin. The new species <em>Alvinonemertes tilici</em> sp. nov., found during the research cruise #94 aboard the R/V <em>Akademik M.A. Lavrentyev</em> in the Emperor Seamounts, has proven to be very close morphologically and genetically to <em>A. dariae</em> Sagorny et al., 2022 from the methane Parrita Seep, off Costa Rica. As a phylogenetic analysis based on five gene markers (cytochrome <em>c</em> oxidase subunit I, 1<em>6S</em> rRNA, <em>18S</em> rRNA, <em>28S</em> rRNA, and histone H3) has shown, the genus <em>Alvinonemertes</em> is not monophyletic. Four species of <em>Alvinonemertes</em> are here segregated into a new genus, <em>Sagornya</em> gen. nov. The new species <em>Sagornya iturupica</em> sp. nov. is described based a specimen collected from the bathyal zone in the Sea of Okhotsk. This species is close genetically to <em>S. tatjanae</em> (Sagorny et al., 2022) comb. n. from seeps along the Oregon margin. The family Oerstediidae is divided into two sister groups: the subfamilies Oerstediinae and Tetranemertinae subfam. nov. To date, the new clade <em>Gononemertes</em> is the largest clade in the family Oerstediinae in terms of number of deep-sea and symbiotic species. Examples of close genetic similarity between deep-sea species from the genera <em>Nemertovema</em>, <em>Tetrastemma, Alvinonemertes, Sagornya</em>, and <em>Carinina</em> are considered. The study has shown that the genetic differences between deep-sea hoplonemerteans from the western and eastern Pacific Ocean are lower than those between sibling hoplonemertean species from Pacific shallow waters off North America and Asia. A hypothesis is advanced here that species with limited geographical ranges are frequently found among deep-sea nemerteans. The wide distribution of deep-sea hoplonemerteans can be provided by long-swimming lecithotrophic larvae, as in Cratenemertidae sp. MCZ IZ 45644.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"216 ","pages":"Article 104439"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}