Boulder star coral
Montastrea annularis
(Ellis & Solander, 1786)
Description:
The colonies grow in several morphotypes, that were originally described as separate species. The species occurs as long, thick columns with enlarged, dome-like tops; large, massive mounds; sheets with skirt-like edges; irregularly bumpy mounds and plates or as smooth plates. Colonies up to 3 meter in diameter. The surface is covered with distinctive, often somewhat raised, corallites.
Color:
Shades of green to brown, yellow-brown and gray.
Corallites:
Corallites 2.1-3.5 mm in diameter, with 24-26 septa. The distance between neighboring corallites is between 0.6 and 1.2 mm. Septa and theca raised (M. annularis-corallite). Septa with small teeth. Columella trabecular.
Habitat:
Inhabit most reef environments and the species is often the predominant coral between 7 and 25 m. The flattened plates are most common at deeper reefs, down to 50 m.
Distribution:
Common to abundant Florida, Bahamas and Caribbean.
Remarks:
Recent investigations suggest that this species consists of three or more separate species:
Montastrea annularis , corallite diameter 2.1-2.7 mm, with 24 septa, 1-1.2 mm between neighboring corallites, raised septa and theca and moderately well developed costae. Grows mostly in clusters of long, thick columns with enlarged, dome-like tops.
Montastrea faveolata , corallite diameter 2.1-2.7 mm, with 24 septa, 0.6-0.9 mm between neighboring corallites and poorly developed costae. Grows mostly in large, massive mounds and sheets with skirt-like edges.
Montastrea franksi , corallite diameter 2.5-3.5 mm, with 24-26 septa, 1-1.2 mm between neighboring corallites and well developed costae. Grows mostly in irregularly bumpy mounds and plates.