Аннотация:Groundwater ecosystems are inhabited by unique assemblages of animals, often with restricted distributions and highly specialized traits. Those assemblages sustain ecosystem functioning and contribute to important ecosystem services. Knowledge of the species occurring in those habitats and the main ecological and historical drivers for their distribution is important not only from a theoretical point of view, but also to ensure their optimal conservation and groundwater resources management in the perspective of global change. Unfortunately, despite more than a hundred years of research, most information on the species occurring in groundwaters is either not directly accessible, or scattered across a myriad of publications, personal collections, and databases with often a narrow scope and interoperability. To enhance the accessibility of this information, we have built Stygofauna Mundi. Stygofauna Mundi, named after the compendium published by Lazare Botosaneanu in 1986, is a relational, interactive, interoperable, and open-access database aimed at gathering all available information related to animals inhabiting groundwater environments and connected ecotones. We mined all records available in each data source independently, allowing us to trace the origin of each entry. We included all records for aquatic species found in groundwaters, whether they are permanent residents or present only as aquatic or semi-aquatic life stages. We linked and validated all taxonomic names after the Catalogue of Life, Worms-APHIA platform, GBIF, and GenBank. Each name is connected to a set of metadata including the level of subterranean specialization, lifestyle, and available DNA sequences. Functional traits will be incorporated in a subsequent version. For each locality, Stygofauna Mundi includes coordinates (available for 87% of the localities so far), as well as geographical and geological data interoperable with most regional and national cave cadasters and open access databases, such as Global Lithological Map, HydroAtlas, GMBA Mountain Inventory, Global Hydrogeological Maps 2.0, World Administrative Regions, Marine Ecoregions, and OpenStreetMap. The database contains 388,872 records, extracted from 11,661 data sources written in 28 languages. These records account for 52,120 localities and 31,338 taxonomic entities. The localities include springs (N=18,958); marine, coastal, and inland caves and mines (N=12,361); interstitial environments in lakes, seashores, and rivers (N=10,453); wells and boreholes (N=9,326); as well as groundwater-fed and anchialine pools (N=1,022). While they cover all continents, records originate mostly from Europe (N=24,511) and North America (N= 13,216). The most taxon rich are Hexapoda (N=5,407), followed by Copepoda (N=3,892), Nematoda (N=3,802), Mollusca (N=3878), Platyhelminthes (N=2,200), Annelida (N=2,038), Amphipoda (N=2,014), and Acari (N=1,765). By means of Stygofauna Mundi, we will describe firstly the taxonomic and geographic biases that affect global knowledge on groundwaters. We will then expand on the habitat classification by Botosaneanu in the original Stygofauna Mundi combining data on the hydrology, geology, chemical profiles, and community composition within localities. Next, we will study the main drivers for changes in taxonomic alpha and beta diversity at a global scale, both across different animal lineages and groundwater ecosystems. Finally, we will explore how to use these data for boosting global conservation plans for the groundwater ecosystems, e.g., by proposing a spatially-explicit strategy to better incorporate groundwater biodiversity into the expanding national and international networks of protected areas.