Entity-relationship diagram for the RivFISH database. Each table contains one primary key (PK), with unique values that may link to other tables through a foreign key (FK). RivFISH includes a total of six tables, covering species' taxonomy (“Current_species”, “Species_names”), spatial data (“CCM_sea_outlets” and “Species_basins”, with the last associated to the references from the literature) and IUCN information (“IUCN_assessments”).