831 species

Heterocyathus aequicostatus

Milne Edwards and Haime, 1848


Milne Edwards and Haime, 1848

Characters: Sometimes zooxanthellate. Corals are solitary, free-living, and have a flat base. They have a commensal relationship with a sipunculid worm (Aspidosiphon corallicola) which moves the coral about on soft substrates and prevents it from becoming buried. Tentacles are usually extended only at night. Larvae initially settle on a microgastropod shell which they usually envelop during subsequent growth. Corals have only one corallite which is circular. They have prominent costae.

Colour: Pale brown, often with a greenish oral disc.

Similar Species: Heterocyathus and the dendrophylliid Heteropsammia cochlea are structural and ecological equivalents. Heteropsammia lacks the prominent costae of Heterocyathus.

Habitat: Always found on soft horizontal substrates at depths of 20 metres or more, usually in association with Heteropsammia cochlea and Cycloseris cyclolites.

Abundance: May be locally abundant (commonly 40 individuals per square metre).

Taxonomic Note: The type species of Heterocyathus Milne Edwards and Haime, 1848. A species complex. Azooxanthellate forms of this species may occur outside the distribution record.

COTW History since Veron (2000a)
  • Family: All families are currently under review
  • Genus/species: No change