Colonies are massive and cerioid or have several centres in a short series. Columellae are rudimentary. Septa are thin, with pointed fine teeth.
Usually mottled grey-green with valleys and walls of contrasting colours.
Most reef environments, but especially surge channels.
Taxonomic note: This species was previously placed in the genus Isophyllastrea. Source reference: Veron (2000). Taxonomic references: Matthai (1928), Cairns (1982), Fenner (1993) (all as Isophyllastrea rigida). Additional identification guides: Colin (1978), Humann (1993) (both as Isophyllastrea rigida).
displaying probable distribution of species. Points indicate recorded sightings from OBIS.
Isophyllia rigida.Caribbean.This species forms small hemispherical colonies which short have little variation on growth-form or colour.Charlie Veron.