Progress in Oceanography最新文献

{"title":"Diversity and connectivity of deep-sea Amphipoda of the Bering Sea and the Aleutian Trench revealed with DNA barcoding","authors":"Anna M. Jażdżewska ,&nbsp;Anne Helene S. Tandberg ,&nbsp;Wiktor Leszczyński","doi":"10.1016/j.pocean.2025.103655","DOIUrl":"10.1016/j.pocean.2025.103655","url":null,"abstract":"<div><div>Amphipoda are speciose and abundant in all marine habitats and are proven to be important food source for higher trophic levels. These crustaceans are brooders with no planktonic larval stage, so migration of species depend mainly on swimming capacities of adult animals.</div><div>The aims of the present work were: 1) characterizing the diversity of abyssal and hadal amphipods of the Bering Sea (BS) and the Aleutian Trench (AT), 2) studying the amphipod species distribution as well as 3) inferring the connectivity between North East Pacific amphipod fauna and the other deep-sea regions of the world ocean.</div><div>The material was collected with and epibenthic sledge from two stations in the South East BS, three stations on the northern slope of the AT, three stations on the southern slope of the AT and six stations in the hadal of the AT. A representation of all collected amphipods was initially sorted into families and preferably morphospecies and subjected to cytochrome <em>c</em> oxidase subunit I gene (COI) barcoding.</div><div>The barcoding of 575 individuals resulted in 460 sequences that were ascribed to 182 Molecular Operational Taxonomic Units (MOTUs). At least 25 families, 31 genera and six known species were identified. The families (or groups of families) that dominated barcoded material in terms of abundance were: Oedicerotidae (76 ind.), Eusiridae (75 ind.) and Lysianassoidea indet. (61 ind.), while the most speciose groups were: Lysianassoidea indet. (31 MOTUs), followed by Pardaliscidae (29 MOTUs) and Oedicerotidae (28 MOTUs). Almost three quarters of all MOTUs were singletons or doubletons, however as many as 46 MOTUs appeared to be shared with other regions of the World Ocean. The Bering Sea and both slopes of the trench appeared to harbour significantly higher number of amphipod MOTUs (51–61 MOTUs) than the hadal zone of the AT (33 MOTUs). The highest faunal exchange appeared to be between abyssal and hadal zones of the AT and similar depth zones of the Kuril-Kamchatka Trench (39 MOTUs), the second most connected region was the abyss of Clarion-Clipperton Zone (11 MOTUs). The BS fauna demonstrated high uniqueness with only four MOTUs shared with AT abyss and hadal as well as with four MOTUs shared with NW Pacific.</div><div>The study confirmed high species richness of another deep-sea region of the World, formerly almost completely unknown.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"242 ","pages":"Article 103655"},"PeriodicalIF":3.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785681","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":"Ecological and spatial factors shaping abyssal and hadal peracarid crustacean communities in the eastern Aleutian Trench (NE Pacific)","authors":"Davide Di Franco ,&nbsp;Stefanie Kaiser ,&nbsp;Andreas Kelch ,&nbsp;Mathis Preikschardt ,&nbsp;Magdalena Błażewicz ,&nbsp;Nils Brenke ,&nbsp;Sarah Gerken ,&nbsp;Kamila Głuchowska ,&nbsp;Karen Jeskulke ,&nbsp;Henry Knauber ,&nbsp;Katharina Kohlenbach ,&nbsp;Anne Helene S. Tandberg ,&nbsp;Anna Jażdżewska ,&nbsp;Angelika Brandt","doi":"10.1016/j.pocean.2025.103651","DOIUrl":"10.1016/j.pocean.2025.103651","url":null,"abstract":"<div><div>The abyssal and hadal deep sea, characterised by high pressures, low temperatures, and limited light availability, hosts a remarkable diversity of organisms that have adapted to these harsh conditions. Despite its vastness, the deep sea remains relatively unexplored, and our understanding of the factors governing its community composition, diversity, and abundance is still limited. In this study, we aim to elucidate the various factors that contribute to shaping deep-sea peracarid communities and provide insights into their ecological dynamics. Benthic material was collected during the AleutBio (SO293) expedition aboard the RV <em>Sonne</em> from July 24th to September 6th, 2022 in the Northeast Pacific Ocean. A total of 19 samples were collected with an epibenthic sledge at depths ranging from 3,517 to 7,254 m. In total, 5,400 peracarid specimens were collected, with amphipods and isopods being the most dominant groups, accounting for 35 % and 36 % (1,546 and 1,591 ind./1,000 m haul) respectively, followed by cumaceans and tanaidaceans, which each contributed 13 % of the total peracarid composition (584 and 556 ind./1,000 m). Hierarchical cluster analysis and non-metric multidimensional scaling (nMDS) revealed dissimilarity in the abundance patterns between hadal and abyssal stations, highlighting significant variation in assemblage structure. Further Redundancy Analysis (RDA), showed that depth was the primary environmental factor driving peracarid abundance across the stations. The results contribute valuable insights into the distribution patterns of peracarids in the Aleutian Trench region and underscores the need for further investigations into the role of environmental variables in structuring deep-sea communities.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103651"},"PeriodicalIF":3.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786139","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":"Ice melt season in the Kara Sea: Size-fractionated primary production and chlorophyll-a, evolution of the subsurface chlorophyll maximum layer and its contribution to total water column values","authors":"Andrey B. Demidov ,&nbsp;Tatiana A. Belevich ,&nbsp;Anna V. Kostyleva ,&nbsp;Valentina M. Sergeeva ,&nbsp;Alexander A. Polukhin ,&nbsp;Vladimir A. Artemiev ,&nbsp;Andrey A. Nedospasov ,&nbsp;Dragosh I. Migali ,&nbsp;Mikhail V. Flint","doi":"10.1016/j.pocean.2025.103652","DOIUrl":"10.1016/j.pocean.2025.103652","url":null,"abstract":"<div><div>The characteristics of phytoplankton variability during spring sea ice retreat are poorly understood at the regional scale. To address this gap, three cruises were conducted in the Kara Sea from late June to early August during sea ice retreat. The present study focused on the variability of primary production (PP), chlorophyll-<em>a</em> (Chl-<em>a</em>) concentration of total and size-fractionated phytoplankton, the evolution of the subsurface Chl-<em>a</em> maximum layer (SCML), and its contribution to the total water column PP (IPP_tot) and integrated photosynthetic layer Chl-<em>a</em> (Chl_ph). During the study period, the ice-edge phytoplankton bloom was characterised by high values of IPP_tot and Chl_ph (up to 1352 mgC m⁻² d^–1 and 151.53 mg m⁻², respectively) and a dominance of microphytoplankton (&gt;20 µm) in the water column (88 % of IPP_tot and 77 % of Chl_ph on average) and in the SCML (52 % of PP and 64 % of Chl-<em>a</em> on average). The role of nano- (3 – 20 µm) and picophytoplankton (&lt;3 µm) increased with sea ice retreat. During the melt season, micro-, nano- and picophytoplankton contributed on average 50, 14 and 36 % to IPP_tot and 60, 15 and 25 % to Chl_ph, respectively. PP and Chl-<em>a</em> associated with the SCML contributed 32 % to IPP_tot and 76 % to Chl_ph. The rapid decline in IPP_tot during sea ice retreat suggests that Arctic warming, sea ice loss, and the significant increase in total PP due to newly exposed open water areas may not be accompanied by an increase in photosynthetic activity in the Arctic Ocean. During the ice melt season in the Kara Sea ∼1/3 of IPP_tot and 3/4 of Chl_ph are concentrated in the SCML, emphasizing its importance in the seasonal trophic balance and in the development of PP algorithms.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103652"},"PeriodicalIF":3.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785777","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":"Monthly and seasonal variations in ocean near-surface gradients around Santo Antão Island: A 20-year MODIS-aqua study","authors":"Cassandra Santos-Pacheco ,&nbsp;Issah N. Suleiman ,&nbsp;Tiago Da Rosa Serpa ,&nbsp;Miguel Figueiredo ,&nbsp;Ana Martins","doi":"10.1016/j.pocean.2025.103654","DOIUrl":"10.1016/j.pocean.2025.103654","url":null,"abstract":"<div><div>Understanding the baseline environmental conditions of the Santo Antão marine ecosystems is essential for effective conservation. This study characterised the long-term spatial variability of near-surface biophysical properties of the waters surrounding Santo Antão by utilizing 20 years of MODIS-Aqua Level-2 imagery with 1 km spatial resolution for Ocean Colour and Thermal Infrared parameters, supplemented by altimetry data. Sea Surface Temperature (SST) results revealed a persistent thermal gradient, with warmer waters in the NW-W-SW quadrant and cooler waters in the NE-E-SE quadrant, indicating the influence of regional oceanic currents and interactions between subtropical and tropical gyres. Chlorophyll <em>a</em> (Chl <em>a</em>), Diffuse Attenuation Coefficient (Kd₄₉₀), and Particulate Organic Carbon (POC) exhibited similar spatial gradients and were highly correlated, reflecting the oligotrophic nature of Case-1 waters. Notably, the correlation between Kd₄₉₀ and Chl a was strong (r ≈ 0.92), while POC showed an even higher correlation (r ≈ 0.95), reinforcing their roles as significant indicators of phytoplankton biomass. In contrast, Particulate Inorganic Carbon (PIC) concentrations displayed distinct spatial patterns and demonstrated a weak negative correlation with Chl <em>a</em> (r ≈ -0.27), indicating that PIC operates independently of the bulk phytoplankton community represented by Chl <em>a</em>. This independence emphasises the need to interpret PIC values with caution, as they may not accurately reflect biological productivity in these waters. Photosynthetically Available Radiation (PAR) displayed limited seasonal variation and a weak negative correlation with Chl <em>a</em>, suggesting that light availability is not a primary limiting factor for phytoplankton productivity in the region. The observed spatial patterns and gradients in biophysical parameters are interpreted in the context of various ocean–atmosphere interactions, including the prevailing northeast trade winds, Sea Surface Height (SSH), and surface currents, which are modulated by larger-scale circulation patterns. These mechanisms should influence nutrient availability and ultimately affect productivity distribution around the island. Overall, this study highlights the complex interplay of monthly and seasonal ocean–atmosphere spatial dynamics, along with regional and large-scale oceanographic conditions, in shaping the near-surface gradients around Santo Antão. By integrating these diverse datasets, this study provides new insights into the region’s ocean dynamics, emphasising its significance for conservation efforts in this area.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103654"},"PeriodicalIF":3.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785688","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":"Internal tides in the Mediterranean Sea","authors":"Bethany McDonagh ,&nbsp;Jin-Song von Storch ,&nbsp;Emanuela Clementi ,&nbsp;Nadia Pinardi","doi":"10.1016/j.pocean.2025.103647","DOIUrl":"10.1016/j.pocean.2025.103647","url":null,"abstract":"<div><div>The generation and propagation sites of internal tides in the Mediterranean Sea are mapped through a comprehensive high-resolution numerical study. Two ocean general circulation models are used for this: NEMO v3.6, and ICON-O, both hydrostatic ocean models based on primitive equations with Boussinesq approximation, where NEMO is a regional Mediterranean Sea model with an Atlantic box, and ICON a global model. Internal tides are widespread in the Mediterranean Sea. The primary generation sites: the Gibraltar Strait, Sicily Strait/Malta Bank, and Hellenic Arc, are mapped through analysis of the tidal barotropic to baroclinic energy conversion. Semidiurnal internal tides can propagate for hundreds of kilometres from these generation sites into the Algerian Sea, Tyrrhenian Sea, and Ionian Sea respectively. Diurnal internal tides remain trapped along the bathymetry, and are generated in the central Mediterranean Sea and southeastern coasts of the basin. The total energy used for internal tide generation in the Mediterranean Sea is 3.31 GW in NEMO and 1.52 GW in ICON. Wavelengths of the first baroclinic modes of the M2 tide are calculated in various regions of the Mediterranean Sea where internal tides propagate, comparing model outputs to a theory-based calculation. The models are also validated and intercompared to investigate the differences between them in their representation of internal tides.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103647"},"PeriodicalIF":3.6,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839870","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":"Halocline as an environmental barrier for the larvae of Arctic marine benthic invertebrates","authors":"Weronika Patuła ,&nbsp;Marta Ronowicz ,&nbsp;Piotr Kukliński ,&nbsp;Agata Weydmann-Zwolicka","doi":"10.1016/j.pocean.2025.103649","DOIUrl":"10.1016/j.pocean.2025.103649","url":null,"abstract":"<div><div>Many marine benthic invertebrates possess a pelagic larval life stage (meroplankton) that is highly sensitive to environmental changes, influencing their spatial distribution, survival, and settlement. This study was conducted on the adjacent shelf and in Kongsfjorden, a high-Arctic fjord system in Svalbard, where the Kongsfjorden Transect (KT), influenced by Arctic and Atlantic oceanic regimes, shows strong variability in physico-chemical conditions. Consequently, changes in environmental conditions, including the depth of the halocline, can act as a physical barrier for organisms, affecting local biodiversity. We, investigated meroplankton vertical distribution in relation to the halocline, and hypothesized that the salinity gradient acts as a barrier for larvae, influencing their movements, distribution and diversity. We identified 25 meroplankton morphotypes along the KT, with Bivalvia veligers as the dominant taxon. Taxonomic assemblages differed significantly between above (AH) and below (BH) the halocline. More abundant Echinodermata larvae characterized the AH assemblage, which remained compositionally similar throughout the studied transect. In contrast, Polychaeta larvae were characteristic of the BH assemblage with greater spatial variability, consistent with decreasing temperature, salinity, and chlorophyll <em>a</em> concentration, towards the inner part of the fjord. By integrating detailed morphotype analysis with hydrographic data, we showed that the halocline is a barrier for meroplankton larvae, defining their vertical distribution, abundance, and taxonomic composition; we also present the indicator taxa of the AH and BH assemblages. Our results emphasize the role of the salinity gradient in shaping larval communities and support their potential role as early indicators of environmental change in the Arctic fjords.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"242 ","pages":"Article 103649"},"PeriodicalIF":3.6,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145759816","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":"Variability of near-inertial internal wave energy in the Kuroshio extension from CPIES array observations","authors":"Y.R. Mu ,&nbsp;Y.S. Xu ,&nbsp;J.H. Park","doi":"10.1016/j.pocean.2025.103650","DOIUrl":"10.1016/j.pocean.2025.103650","url":null,"abstract":"<div><div>Near-inertial internal waves (NIIWs) play a central role in ocean mixing and energy transfer, and understanding their local variability is essential for quantifying ocean energetics. This study investigates the local drivers of NIIW variability in the Kuroshio Extension System Study (KESS) region using observations from a Current-and Pressure-sensor-equipped Inverted Echo Sounder (CPIES) array deployed over a 600 km by 600 km area, assuming negligible net NIIW flux. We developed an empirical model to quantify the contributions of wind-induced near-inertial energy flux (WNEF), mixed layer depth (MLD), and relative vorticity (<span><math><mrow><mi>ζ</mi></mrow></math></span>), which have dominant influences on NIIW variability, accounting for 39 %, 41 %, and 20 % of the variability, respectively. WNEF and MLD positively correlate with NIIW energy, while <span><math><mrow><mi>ζ</mi></mrow></math></span> shows a negative correlation. These findings highlight the significance of local processes in modulating NIIW energy and improving our understanding of ocean mixing dynamics by transitioning from qualitative to quantitative analysis.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103650"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731518","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":"Fine-scale hydrodynamic variability at Majuro Atoll, Republic of the Marshall islands. Part I: Flow variability","authors":"Yan Jia ,&nbsp;Weifeng (Gordon) Zhang ,&nbsp;Steven J. Lentz ,&nbsp;Nathaniel R. Mollica ,&nbsp;Gonzalo Pérez-Rosales ,&nbsp;Anne L. Cohen","doi":"10.1016/j.pocean.2025.103648","DOIUrl":"10.1016/j.pocean.2025.103648","url":null,"abstract":"<div><div>Majuro, a coral atoll in the Central Pacific, consists of rim reefs and low-lying islands surrounding a lagoon 40 km long, 10 km wide, and averaging 35 m deep. The lagoon is connected to the open ocean through shallow reef flats along the northwestern and western rims, and a 40 m deep channel in the northern rim. Spatiotemporal variability of lagoon hydrodynamics is characterized with a 15-year (2009–2023) simulation of a high-resolution ocean-wave coupled model. In winter, strong northeasterly winds generate high waves that approach the atoll from the northeast, breaking on the reef flats to the northwest of the lagoon, and driving strong flow across the reef flats into the lagoon. The wave- and wind-driven flows together forms a counterclockwise vortex pattern over the entire water column in the western lagoon, leading to a strong barotropic outflow through the deep channel. The lagoon circulation in winter is thus <em>laterally sheared</em>. In summer with weaker northeasterly winds, the wave-driven overflow across the northwestern reef flats weakens. In fall, episodic westerly winds drive open ocean water across the western reef flat into the lagoon. The weak winds in summer and fall allow the development of <em>vertically sheared</em> flows in the lagoon, with surface flows generally aligned with winds and subsurface flows opposing winds. This study demonstrates that lagoon circulation, varying over the scale of O(100 m-10 km), differ drastically from that in the surrounding ocean, can directly affect coral reef communities, and is thus critical for effective marine resource management.</div><div>Plain language summary.</div><div>Majuro Atoll, Republic of Marshall Islands, is located in the Central Pacific and is made up of rim reefs and islands surrounding lagoon of 40 km long and 10 km wide. The lagoon is separated from the open ocean by shallow rim reefs on its north and west sides and an island chain on its south and east sides. The deep part of the lagoon is connected to the open ocean by a 40-m deep channel in the north. This work uses a high-resolution computer model to simulate flows and temperature conditions in 2009–2023 and study how the lagoon flow conditions change in space and time. The model shows that the lagoon flows are influenced not only by winds throughout the year but also by high waves approaching the atoll from the northeast. As the waves break on the north shore of the atoll, they push a significant amount of water into the lagoon. Some of the lagoon water then flow out into the open ocean through the deep channel. Circulation in the lagoon changes dramatically with the winds. All these flow changes in the lagoon cause the lagoon environment to differ significantly from the open ocean. Such fine-scale changes in lagoon conditions likely affect coral health, influence their responses to climate change, and provide key information for effective coral reef conservation and protection.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103648"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732113","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":"Does an arctic circumpolar distribution exist for deep-sea sponges? Unravelling the systematics of Stylocordyla borealis (Porifera: Demospongiae) through integrative taxonomy","authors":"Franziska I. Theising ,&nbsp;Ute Hentschel ,&nbsp;Kathrin Busch ,&nbsp;Angelika Brandt ,&nbsp;Francisca Carvalho ,&nbsp;Joana R. Xavier ,&nbsp;Andreu Santín Muriel","doi":"10.1016/j.pocean.2025.103646","DOIUrl":"10.1016/j.pocean.2025.103646","url":null,"abstract":"<div><div>Delineating species boundaries is crucial for understanding deep-sea sponge biodiversity and biogeographical patterns, which aids in conservation efforts such as the establishment of Marine Protected Areas. The demosponge <em>Stylocordyla borealis</em> (Lovén, 1868) was historically thought to have a widespread distribution across various ocean basins. However, recent studies using morphological and molecular tools revealed a complex of several distinct species, each with specific biogeographical ranges. While a cosmopolitan distribution for <em>S. borealis</em> has now been disproven, uncertainties about its wide-ranging records and many subspecies continue to persist. The present study focuses on the Arctic circumpolar distribution of the North Atlantic <em>S. borealis</em> and its North Pacific subspecies <em>S. borealis eous</em> Koltun, 1966. Morphological traits, phylogenetic reconstruction with genetic markers (<em>COI</em>, <em>28S</em>), and <em>16S</em> amplicon sequencing of microbial communities were used to explore phenotypic and genetic diversity within <em>S. borealis</em> Atlantic and Pacific populations.</div><div>Results showed that <em>S. borealis</em> is confined to the North Atlantic and Boreo-Arctic regions, while <em>S. borealis eous</em> inhabits the North Pacific and should be taxonomically elevated to a distinct species, named <em>Stylocordyla eous</em> Koltun, 1966 comb. nov. This distinction underscores the contentious nature of the subspecies concept in sponge taxonomy and highlights the value of molecular techniques. In this study, microbial fingerprinting enabled species-level resolution within the <em>Stylocordyla</em> genus, demonstrating the importance of <em>16S</em> microbial amplicon sequencing as a complementary tool for Porifera taxonomy. These insights contribute to a deeper understanding of deep-sea sponge biodiversity and distribution.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103646"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731519","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":"No discovery without exploration: Deep-sea sampling across the Pacific reveals three new genera of Typhlotanaidae (Crustacea: Tanaidacea)","authors":"Marta Gellert ,&nbsp;Magdalena Błażewicz ,&nbsp;Chee Kong Chim ,&nbsp;Graham J. Bird","doi":"10.1016/j.pocean.2025.103644","DOIUrl":"10.1016/j.pocean.2025.103644","url":null,"abstract":"<div><div>This study examines the “slender-bodied” representatives of the family Typhlotanaidae (Crustacea: Tanaidacea), characterized by straight pereonite margins and scale-like ornamentation on the chelipeds, collected from multiple deep-sea Pacific localities, including the Aleutian Trench, the Sea of Okhotsk, the Clarion-Clipperton Fracture Zone, and eastern Australia.</div><div>Integrative analyses combining detailed morphology and molecular data (histone H3 marker) were used to reassess the systematics of these taxa. Morphological comparisons of the family’s type species <em>Typhlotanais aequiremis</em> and related slender-bodied forms (<em>Typhlotanais plebejus</em>, species of <em>Starkus</em>, <em>Baratheonus</em>, and the “spinicauda” group) revealed a pattern of extensive homoplasy, particularly in cheliped ornamentation and pereonite morphology. These convergent traits have historically obscured true phylogenetic relationships within the group.</div><div>Genetic results, although available for a limited number of specimens, provided strong support for deep genetic divergence among several morphologically similar lineages. The molecular phylogeny recovered a well-supported monophyletic group, with new species forming a distinct, independent clade consistent with genus-level differentiation.</div><div>By integrating both data sources, this study establishes three new genera and four new deep-sea species. These taxa collectively highlight the cryptic diversity and complex evolutionary history of Typhlotanaidae. The discovery of closely related yet geographically distant species indicates possible trans-Pacific connections among deep-sea populations. An updated identification key and a review of the morphological diversity of slender-bodied Typhlotanaidae are also provided, contributing to the ongoing redefinition of generic boundaries within this morphologically challenging family.</div><div>LSIDurn:lsid:zoobank.org:pub:037D9EC3-1945–4082-971B-EB4FBB5ABE21.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"242 ","pages":"Article 103644"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732110","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}