Acropora listeri
Brook, 1893
This species shows wide geographic variation. Red Sea colonies are especially distinct.
Description: Colonies are irregular clumps or corymbose plates with thick branches of highly irregular length and shape. Branches may be tapered (in wave washed habitats), conical, dome-shaped or globular (in less exposed habitats), depending on the degree of formation of axial corallites. One or more axial corallites may occur on branch ends or, commonly, there are no axial corallites. Radial corallites are irregularly immersed to tubular and often have slit-like openings and pointed rims, giving colonies a spiny appearance.
Color: Cream or brown.
Habitat: Upper reef slopes, especially those exposed to strong wave action.
Abundance: Uncommon.
Similar Species: Acropora polystoma, which has well defined axial corallites, does not form dome-shaped or globular branches and has less irregular radial corallites. See also A. lutkeni.
Source reference: Veron (2000). Taxonomic references: Veron and Wallace (1984), Wallace (1999). Identification guides: Veron (1986), Nishihira and Veron (1995).
Colonies (centre) commonly have short globular branches when in shallow water exposed to strong wave action. Great Barrier Reef, Australia Photograph: Charlie Veron
Detail of branch ends showing the common slit-like openings of radial corallites. Tahiti Photograph: Gustav Paulay
Short irregular branches in shallow water. Great Barrier Reef, Australia Photograph: Ed Lovell
Skeletal detail. Incipient axial and radial corallites.