The content of the registry is edited and maintained by scientific specialists on each group of organism. These
taxonomists control the quality of the information, which is gathered from the primary scientific literature as well as from some external regional and taxon-specific databases. WoRMS maintains valid names of all marine organisms, but also provides information on
synonyms and invalid names. It is an ongoing task to maintain the registry, since new species are constantly being discovered and described by scientists; in addition, the nomenclature and taxonomy of existing species is often corrected or changed as new research is constantly being published. Subsets of WoRMS content are made available, and can have separate badging and their own home/launch pages, as "subregisters", such as the
World List of Marine Acanthocephala,
World List of Actiniaria,
World Amphipoda Database,
World Porifera Database, and so on. As of December 2018 there were 60 such taxonomic subregisters, including a number presently under construction. A second category of subregisters comprises regional species databases such as the
African Register of Marine Species,
Belgian Register of Marine Species, etc., while a third comprises thematic subsets such as the
World Register of Deep-Sea species (WoRDSS),
World Register of Introduced Marine Species (WRiMS), etc. In all of these cases, the base data are entered and held once only as part of the WoRMS data system for ease of maintenance and data consistency, and are redisplayed as needed in the context of the relevant subregister or subregisters to which they may also belong. Certain subregisters expand content beyond the original "marine" concept of WoRMS by including freshwater or terrestrial taxa for completeness in their designated area of interest; such records can be excluded from a standard search of WoRMS by selecting appropriate options in the online search interface. ==History==