Clavularia crassa

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Cnidaria · Class: Octocorallia · Order: Malacalcyonacea · Family: Clavulariidae · Genus: Clavularia.

Accepted name: Clavularia crassa · Authority: (Milne Edwards, 1848) · Taxonomic status: accepted · AphiaID: 125338.

Synonyms and superseded combinations recorded for this taxon: Anthelia crassa (Milne Edwards, 1848); Anthelia petricola (Kowalevsky & Marion, 1883); Clavularia inordinata Tixier-Durivault & Lafargue, 1968; Clavularia ochracea von Koch, 1878; Clavularia petricola Kowalevsky & Marion, 1882; Clavularia steveninoae d'Hondt & Tixier-Durivault, 1975; Cornularia crassa Milne Edwards, 1848.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=125338 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Clavularia crassa. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Habitat zone: sessile · Aquarium trade: never/rarely.

SeaLifeBase notes: Known from the infralittoral zone (Ref. 85338).

Source: SeaLifeBase species summary (SpecCode 139303) — https://www.sealifebase.se/summary/Clavularia-crassa.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

372 georeferenced occurrence records for Clavularia crassa are published through GBIF from 8 countries or marine areas. The map above plots 32 distinct locations from a sample of 372 records, omitting 23 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Spain (172); France (145); Croatia (21); Greece (12); Italy (11); Australia (5); Portugal (4); Morocco (2).

Marine regions with a valid WoRMS distribution record: Mediterranean Sea; European waters (ERMS scope); Greek Exclusive Economic Zone.

Source: GBIF Occurrence Search (taxonKey 5184870) — https://www.gbif.org/occurrence/search?taxon_key=5184870&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=125338 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Clavularia crassa (Milne Edwards, 1848) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 50020621) — https://www.iucnredlist.org/species/50020621/0; GBIF IUCN Red List category endpoint (taxonKey 5184870) — https://api.gbif.org/v1/species/5184870/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

Clavularia crassa forms small colonies of up to about fifty individual polyps growing from a stolon. This grows along the surface of the substrate and it, and the bases of the polyps, are orangish-brown.

Each polyp is up to 10 mm long and 2 mm wide. The column is slender and creamy-white and the eight long, feathery tentacles are either transparent white, or colourless flecked with white. The oral surface is stiffened by calcareous sclerites.

Other soft corals with which this species might be confused include Cornularia cornucopiae and Sarcodictyon catenatum. C. cornucopiae has shorter polyps and narrower stolons, and its tissues does not contain sclerites. S. catenatum has much smaller polyps and its thick stolon is brick red and clearly visible.

Clavularia crassa is found in the Mediterranean Sea and the proximate areas of the eastern Atlantic Ocean, the coasts of Portugal and Algeria. It occurs in positions with moderate to high movement of water and its depth range is from about 1 to 33 metres (3 to 100 ft).

The polyps of Clavularia crassa are able to partially retract. When extended they feed on zooplankton which are filtered from the water by the tentacles.

This octocoral is often to be found growing on the rhizomes of the seagrass known as Neptune grass (Posidonia oceanica), as well as on algae and sponges. From late June onwards, eggs are extruded through the mouths of the polyps and remain stuck together in small orange clusters. They are brooded on the outer surface of the polyps.

Source: Wikipedia: Clavularia crassa — https://en.wikipedia.org/wiki/Clavularia_crassa (CC BY-SA 4.0). Accessed 2026-09-25.