Deepwater branching coral (Solenosmilia variabilis)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Cnidaria · Class: Hexacorallia · Order: Scleractinia · Family: Caryophylliidae · Genus: Solenosmilia.

Accepted name: Solenosmilia variabilis · Authority: Duncan, 1873 · Taxonomic status: accepted · AphiaID: 135168.

Synonyms and superseded combinations recorded for this taxon: Solenosmilia jefferyi Alcock, 1898; Solenosmilia jeffreyi Alcock, 1898.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=135168 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

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

Depth range: 220–2430 m · Habitat zone: reef-associated.

SeaLifeBase notes: Minimum depth from Ref. 106682. Azooxanthellate (Ref. 121684). On rocky reefs in mesophotic to deep waters (Ref. 121684). Found at depths of 220 (Ref. 106682) to 2430 m (Ref. 119632). Bioherm-forming colonial coral widely distributed on seamounts (Ref. 119633).

Source: SeaLifeBase species summary (SpecCode 46402) — https://www.sealifebase.se/summary/Solenosmilia-variabilis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

9,218 georeferenced occurrence records for Solenosmilia variabilis are published through GBIF from 54 countries or marine areas. The map above plots 45 distinct locations from a sample of 3,000 records, omitting 1 inland record 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: Australia (6,022); United States of America (1,270); New Zealand (1,163); Portugal (90); United Kingdom of Great Britain and Northern Ireland (75).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2259062) — https://www.gbif.org/occurrence/search?taxon_key=2259062&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=135168 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Description and natural history (Wikipedia)

Solenosmilia variabilis grows into small bushy colonies, the dichotomous branches often joining. It grows from an encrusting base on which there are a few corallites. The branches are thick near the base of the colony but more slender above; sometimes upper branches are just 3 to 5 mm in diameter. The coenosteum can be smooth and white, granular, glossy and pale grey, or ridged with eight to ten transverse costae. The corallites are up to 5 mm in diameter, with the septa grouped in sixes, arranged in three or more cycles. Growth of the colony is by intratentacular budding.

S. variabilis has a semi-cosmopolitan distribution. It is widespread in both the Atlantic and Indian Oceans and has a circumpolar distribution in the Southern Ocean. Locations where it has been found include off South Africa, off Prince Edward Island, off Île Saint-Paul, off southeastern Australia, off New Zealand, off South Orkney Islands, off Tristan Island, on the Hjort Seamount (south of Macquarie Island), on the Macquarie Ridge, and on seamounts in the South Pacific and Drake Passage. Its known depth range is 220 to 2165 m.

S. variabilis is a widespread species of deep sea reef-building coral; in the southwestern Pacific it is the dominant coral species on seamounts and rocky substrates in the depth range 1000 to 1300 m. In this location, it is a major part of a diverse community which is easily damaged by deepwater trawling. It is a long-lived species with a growth rate of about 1 mm per year and it may be adversely affected by ocean acidification and climate change.

Source: Wikipedia: Solenosmilia variabilis — https://en.wikipedia.org/wiki/Solenosmilia_variabilis (CC BY-SA 4.0). Accessed 2026-09-23.

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