Halomitra pileus
Linnaeus, 1758
Description: Colonies are large, free-living, thin and delicate, and circular, dome or bell-shaped. They have no axial furrow. Corallites are widely spaced and increase in size as the colony grows. In small colonies, septo-costae radiate in a fan from the initial point of growth or are perpendicular to the colony margin, in which case they form distinct lines of demarcation. Septa have teeth similar to those of Fungia fungites. Tentacles of mature colonies are extended only at night; those of juvenile colonies are commonly extended during the day.
Color: Pale brown, frequently with bright pink or purple margins. Corallite centres are commonly white.
Habitat: Middle to lower reef slopes protected from wave action and lagoons on soft substrates.
Abundance: Usually uncommon.
Similar Species: Halomitra clavator. Juvenile colonies may resemble Zoopilus echinatus if septo-costae form the pattern described above.
Source reference: Veron (2000). Taxonomic references: Veron and Pichon (1980), Hoeksema (1989). Identification guides: Veron (1986), Nishihira and Veron (1995).
Typical surface appearance with groups of septo-costae running in different directions. Pemba Island, Tanzania Photograph: Charlie Veron
This species usually forms dome-shaped colonies. These have a thin wall and a delicate structure. Papua New Guinea Photograph: Gerry Allen
Corallite detail. Madagascar Photograph: Charlie Veron
Corallite detail. Great Barrier Reef, Australia Photograph: Neville Coleman
Skeletal detail. Detail of septa.