Sinuous cactus coral (Isophyllia sinuosa)

Classification (WoRMS)

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

Accepted name: Isophyllia sinuosa · Authority: (Ellis & Solander, 1786) · Taxonomic status: accepted · AphiaID: 216134.

Synonyms and superseded combinations recorded for this taxon: Isophyllastrea sinuosa (Ellis & Solander, 1786); Isophyllia aglae (Duchassaing & Michelotti, 1860); Isophyllia aspera (Duchassaing & Michelotti, 1860); Isophyllia conferta (Duchassaing & Michelotti, 1860); Isophyllia cylindrica (Duchassaing & Michelotti, 1860); Isophyllia dipsacea Pourtalès, 1871; Isophyllia dipsacea (Dana, 1846); Isophyllia fragilis (Dana, 1846); Isophyllia guadalupensis (Milne Edwards & Haime, 1849); Isophyllia helianthus (Duchassaing & Michelotti, 1860); Isophyllia knoxi (Duchassaing & Michelotti, 1860); Isophyllia marginata (Duchassaing & Michelotti, 1860); Isophyllia multiflora Verrill, 1901; Isophyllia multilamella Pourtalès, 1871; Isophyllia multilamella (Duchassaing & Michelotti, 1860); Isophyllia sinuosa f. multiflora (Verrill, 1902); Isophyllia sinuosa f. sinuosa (Ellis & Solander, 1786); Isophyllia sinuosa f. typica Verrill, 1864; Isophyllia sinuosa var. dipsacea (Dana, 1846); Isophyllia sinuosa var. fragilis (Dana, 1846); Isophyllia spinosa (Edwards & Haime, 1849); Isophyllia strigosa (Duchassaing & Michelotti, 1860); Isophyllia verrucosa (Duchassaing & Michelotti, 1860); Madrepora sinuosa Ellis & Solander, 1786; Meandrina sinuosa (Ellis & Solander, 1786).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=216134 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

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

Depth range: 0–35 m · Habitat zone: reef-associated.

SeaLifeBase notes: Maximum depth from Ref. 116012. Zooxanthellate (Ref. 116012). Throughout the Caribbean in a variety of reef habitats (Ref. 415), e.g., shallow protected reef environments (Ref. 848).

Source: SeaLifeBase species summary (SpecCode 45770) — https://www.sealifebase.se/summary/Isophyllia-sinuosa.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

10,759 georeferenced occurrence records for Isophyllia sinuosa are published through GBIF from 28 countries or marine areas. The map above plots 39 distinct locations from a sample of 3,000 records, omitting 4 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: Virgin Islands (U.S.) (5,694); United States of America (2,379); Puerto Rico (2,127); Bermuda (157); Colombia (150).

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

Source: GBIF Occurrence Search (taxonKey 2260360) — https://www.gbif.org/occurrence/search?taxon_key=2260360&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=216134 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Isophyllia sinuosa (Ellis & Solander, 1786) 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 133591) — https://www.iucnredlist.org/species/133591/0; GBIF IUCN Red List category endpoint (taxonKey 2260360) — https://api.gbif.org/v1/species/2260360/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Isophyllia sinuosa is a massive coral that forms hemispherical or dome-shaped mounds up to 20 cm across. On the coral surface there are shallow, meandering valleys about 22 mm wide separated by convoluted ridges topped with a central, pale-coloured line. The polyps are large and are situated in the valleys, often in groups of three. Although they are usually retracted into their corallites by day, they are unable to retract completely, giving the coral a fleshy feel when touched. The septa that radiate from the corallites are spiny. At night, when the polyps are fully extended, the coral has a fuzzy appearance. The ridges and valleys are usually made up of contrasting colours. These combinations include green/yellow, green/blue, purplish-blue/white and two shades of brown.

Isophyllia sinuosa is found in the tropical west Atlantic. Its range includes the southern part of the Gulf of Mexico, the Caribbean Sea, southern Florida, the Lesser Antilles, the Bahamas and Bermuda. It occurs on both back and fore reef slopes, on rocks, in lagoons and among seagrasses at depths down to about 15 m.

At night, the polyps of Isophyllia sinuosa extend their tentacles to feed on zooplankton. This coral is a zooxanthellate species, which means that it harbours symbiotic dinoflagellates (unicellular algae) in its tissues. These contain chlorophyll and can provide the coral with organic carbon compounds by photosynthesis. These are important to the coral and provide up to 50% of its nutrient requirements. A well-lit position is essential to zooxanthellate corals and Isophyllia sinuosa is one of the most aggressive corals, defending itself from the risk of being over-shadowed. It is reported to attack other corals or sponges in its close vicinity using an extracoelentric feeding mechanism in which specialised filament-like tentacles extend onto the living tissues of the neighbouring organisms, secreting enzymes which digest them in situ.

Isophyllia sinuosa has a wide range but is generally an uncommon species. It is considered by the IUCN Red List of Threatened Species to be of "Least Concern" as its population is believed to be stable. It is prone to bleaching, when a coral expels its zooxanthellae under stressful conditions, to black band disease, and to white plague. As a shallow water species it shares the threats posed to coral reefs in general which include a rise in sea temperatures, ocean acidification, coral diseases, storm damage, sedimentation, and human activities.

Source: Wikipedia: Isophyllia sinuosa — https://en.wikipedia.org/wiki/Isophyllia_sinuosa (CC BY-SA 4.0). Accessed 2026-09-23.

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