Dataset accompanying the study "Deep water but High latitude: Gastropoda and Scaphopoda of the Central Arctic Ocean"

This Excel file contains the full occurrence dataset used in the study “Deep water but High latitude: Gastropoda and Scaphopoda of the Central Arctic Ocean” (Nekhaev et al.). The file compiles all verified records of deep-water (≥900 m) gastropods and scaphopods from the Central Arctic Ocean based on:(1) new quantitative and qualitative samples collected during the drifting expedition North Pole–41 (2022–2024),(2) revised material from museum collections (Laboratory of Macroecology and Biogeography of Invertebrates of Saint Petersburg State University (LMBI), Zoological Institute of Russian Academy of Sciences (ZIN)), and(3) georeferenced literature records. The dataset provides station-level and lot-level information for all identified molluscs and includes abundance, biomass, and detailed metadata for each sampling event. These data form the basis for all biodiversity, depth-gradient, and distributional analyses presented in the manuscript. Column description The dataset contains the following tables: Supplementary Table S1. Species records of Arctic Gastropoda and Scaphopoda, aggregated by collection lot.: Lot – Internal lot number or specimen batch identifier. Accepted_name – Taxonomically validated species name (Gastropoda or Scaphopoda). Sample_square – Area of the processed subsample (cm or cm² equivalent; used for standardization). Class – Higher taxonomic category (Gastropoda / Scaphopoda). Living_specimens – Number of live individuals in the sample. Empty_shells – Number of empty shells recovered. Eggs – Number of egg capsules, if present. Total_speciemens – Total count of all individuals and shells combined. Living_and_eggs – Sum of living individuals and eggs (used for abundance calculations). Biomass – Wet biomass of molluscs in the lot (g). Number_m2 – Standardized abundance expressed as individuals per square meter. Biomass_m2 – Standardized biomass expressed as g per square meter. Sea – Broad marine region (e.g., Arctic Ocean). Region – Subregion or geomorphological unit (e.g., Lomonosov Ridge, Eurasian slope). Date – Sampling date. Station – Station identifier used during the expedition or in museum records. RV/Expedition – Research vessel or expedition name (e.g., “North Pole–41”). Collector – Person responsible for collecting the sample. N – Latitude (°N). E – Longitude (°E). Depth – Sampling depth in meters. Source – Origin of the record (e.g., NP-41 samples, ZIN collection, published and verifiable literature). Supplementary Table S2. Species records of Arctic Gastropoda and Scaphopoda, aggregated by sampling station Supplementary Table S3. Results of the multi-way analysis of variance (ANOVA) testing the effects of latitude, longitude, depth, and their interactions on molluscan species richness. Use and relevance This dataset provides: The first taxonomically verified baseline inventory of deep-water gastropods and scaphopods in the Central Arctic Ocean. Quantitative estimates of abundance and biomass across depths of 900–4,700 m. Geographically explicit occurrence data suitable for ecological, taxonomic, and biogeographic analyses. These data can be reused for integrative taxonomy, Arctic benthic biodiversity syntheses, macroecological modelling, and comparisons with deep-sea faunas of the Nordic Seas and North Atlantic. Please cite this dataset together with the associated article when using these data in scientific research.