liminfoWoRMS Reference
Free reference guide: WoRMS Reference
About WoRMS Reference
The WoRMS Reference is a searchable quick-reference guide covering the World Register of Marine Species (WoRMS), the authoritative taxonomic database for marine life managed by the Flanders Marine Institute (VLIZ). The reference is organized into five categories: Overview (WoRMS database scope with 240,000+ accepted species, editor system with 500+ expert taxonomists, environment flags for marine/brackish/freshwater/terrestrial habitats, data download options with Darwin Core Archive and CC-BY 4.0 licensing, and special collections for major taxonomic groups), AphiaID (unique numeric identifiers, AphiaRecord structure with fields like scientificname/authority/status/rank, and Life Science Identifiers for permanent citation), Taxonomy (taxonomic status types, synonymy management, classification hierarchy queries, taxon tree browsing, citation formats, type locality, and alternate representations for contested classifications), API (REST API endpoints for name search, vernacular names, distribution, bulk matching, plus R package worrms and Python examples), and Linked DB (Marine Regions MRGID, OBIS integration, subregisters like MolluscaBase and WoRDSS, and taxon attributes).
WoRMS is the backbone of marine biodiversity data standardization. Researchers, marine biologists, and environmental agencies rely on it to resolve taxonomic ambiguity: when a species has been described under multiple names (synonyms), WoRMS links all names to a single accepted name with its AphiaID. This standardization is critical for biodiversity assessments, environmental impact studies, fisheries management, and conservation planning. The database is community-driven, with over 500 taxonomic editors reviewing and maintaining name records for their respective groups, ensuring accuracy through expert peer review rather than automated processes.
This reference covers the WoRMS REST API, which enables programmatic access for large-scale data integration. The API supports searching species by name (with fuzzy matching), retrieving full classification hierarchies, fetching vernacular names across languages, querying geographic distributions linked to Marine Regions, and bulk-matching up to 50 scientific names in a single request. Integration examples are provided for R (worrms package with wm_records_name, wm_classification, wm_children, wm_synonyms) and Python (direct REST calls via requests). All content is browsable with instant search and category filtering in your browser.
Key Features
- WoRMS database overview: 240,000+ accepted species, 500+ expert editors, environment flags, CC-BY 4.0 data downloads, and special collections
- AphiaID system explained: unique taxon identifiers, AphiaRecord fields (scientificname, authority, status, rank, valid_AphiaID), and LSID for permanent citation
- Taxonomy reference: taxonomic status types (accepted/unaccepted/nomen dubium), synonymy resolution, classification hierarchy (kingdom to species), and taxon tree navigation
- REST API endpoints: name search with fuzzy matching, vernacular name lookup, distribution queries, and bulk matching (up to 50 names per request)
- Code examples for R (worrms package) and Python (requests library) showing practical API integration patterns
- Linked database coverage: Marine Regions (MRGID), OBIS ocean biodiversity records, subregisters (MolluscaBase, WoRDSS, IRMNG), and taxon attributes
- Alternate representation handling for contested taxonomies (e.g., Magallana gigas vs Crassostrea gigas) and citation format guidelines
- Instant search and category-based filtering across all WoRMS concepts with no server processing required
Frequently Asked Questions
What is WoRMS and what does this reference cover?
WoRMS (World Register of Marine Species) is the authoritative global database for marine species taxonomy, managed by the Flanders Marine Institute (VLIZ) with over 500 expert editors. This reference covers five areas: Overview (scope, editors, environment flags, downloads), AphiaID (identifiers, record structure, LSID), Taxonomy (status, synonymy, classification, taxon trees, citations), API (REST endpoints for search, vernacular names, distribution, bulk matching, plus R and Python examples), and Linked DB (Marine Regions, OBIS, subregisters, attributes).
What is an AphiaID and why is it important?
An AphiaID is a unique numeric identifier assigned to each taxon in WoRMS. For example, Crassostrea gigas has AphiaID 140656. It is important because it provides a stable, unambiguous reference point for any marine species regardless of name changes, synonymy, or taxonomic reclassification. When you cite an AphiaID or its LSID (urn:lsid:marinespecies.org:taxname:140656), it permanently identifies that taxon. Researchers use AphiaIDs to standardize species data across databases like OBIS, GBIF, and institutional collections.
How does WoRMS handle synonyms?
When a species has been described under multiple names, WoRMS links all synonyms (unaccepted names) to a single accepted name. The /AphiaSynonymsByAphiaID/{id} endpoint retrieves all synonyms for a given taxon. For example, Crassostrea gigas has synonyms including Ostrea gigas (original description name) and Crassostrea angulata (Portuguese oyster). Each synonym has its own AphiaID but includes a valid_AphiaID pointing to the accepted name. The status field indicates whether a name is accepted, unaccepted, nomen dubium, or taxon inquirendum.
How do I use the WoRMS REST API to search for a species?
Send a GET request to /AphiaRecordsByName/{name}, for example: /AphiaRecordsByName/Crassostrea+gigas. The response is a JSON array of AphiaRecord objects. Add like=true for fuzzy matching (useful for misspelled names) and marine_only=true to restrict results to marine species. For bulk operations, POST to /AphiaRecordsByMatchNames with up to 50 scientific names. The API returns matched records with exact, phonetic, near_1, and near_2 matching levels.
What are the linked databases covered in this reference?
The reference covers Marine Regions (MRGID identifiers for geographic areas like EEZs and Large Marine Ecosystems, used in WoRMS distribution data), OBIS (Ocean Biodiversity Information System for species occurrence records, standardized via AphiaID), subregisters (specialist databases like MolluscaBase for mollusks, WoRDSS for deep-sea species, IRMNG for marine and nonmarine genera), and taxon attributes (body size, habitat, IUCN Red List status, functional group, invasive status integrated from external databases).
How do I access WoRMS data programmatically in R or Python?
In R, install the worrms package: install.packages("worrms"). Key functions include wm_records_name("species name") for searching, wm_classification(AphiaID) for taxonomy, wm_children(id) for subtaxa, and wm_synonyms(id) for synonyms. In Python, use the requests library to call the REST API directly: requests.get("https://www.marinespecies.org/rest/AphiaRecordsByName/Crassostrea+gigas").json(). Both approaches return structured data including AphiaID, scientific name, authority, and taxonomic hierarchy.
What is the difference between alternate representations in WoRMS?
Some taxa have multiple valid classifications that are scientifically contested. For example, the Pacific oyster can be classified as either Magallana gigas or Crassostrea gigas depending on which taxonomic revision is followed. WoRMS handles this by listing both as "alternate representations" rather than declaring one correct and the other a synonym. Users can choose which classification they prefer. This approach transparently reflects ongoing scientific debate rather than forcing a premature resolution.
Is any data sent to a server when using this reference?
No. The entire WoRMS reference dataset is embedded in the page and rendered client-side. Searching, browsing categories, and viewing entries all happen within your browser using JavaScript. No species names, search queries, or taxonomic data are transmitted to any server. If you want to query the live WoRMS database, use the REST API endpoints documented in the reference — those queries go directly to the WoRMS servers at marinespecies.org.