TWAInv8

Invertebrates, Algae and Vascular Plants of The Tropical West Atlantic: Bahamas to Brazil, Part 8

To: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 9,

Bob Fenner

Lesser and Greater Starlet Coral

Family Siderastreidae, Vaughn & Wells 1943.

Though hard to make out exactly with a live specimen and nothing to magnify the view, this widespread family's members are unified by characteristics of their individual polyp skeleton (corallite) structure. These are flush with the surrounding carbonate mass (coenosteum) by thick septo-costae, with the septa fused in the middle to form a fan or star-like grouping.

Genus Siderastrea de Blainville 1830. Starlet Coral. Perhaps the most widespread coral genus. Found most everywhere corals are found around the world.

Siderastrea radians. Lesser Starlet Coral. Encrusting plates or irregular domes. Colonies 4-12 inches in diameter. Corallites small (2-3 mm in diameter). Tropical West Atlantic. Bonaire pix.

Siderastrea siderea (Ellis & Solander 1786). Massive or Pink Starlet Coral. Encrusting to massive/boulder-like. 1-6 feet in diameter. Corallites small (3-4.5 mm in diameter). Tropical West Atlantic. Bahamas images.

Family Agariciidae, Gray 1847. All utilize endosymbiotic algae, all colonial. Individual coral polyp skeletons have poorly formed walls, prominent/thickened septo-costae, are immersed in their larger skeletal mass, randomly oriented, spaced, often resembling rough, wrinkled skin. Six living genera.

Genus Agaricia Lamarck 1801. Species are mostly thin vertical plates (sometimes horizontal).

Agaricia agaricites (Linnaeus 1758). Form complex relatively thick layers of connected bifacial fronds. Upright or encrusting/horizontal. Two Bahamas images, one or "forma danai" in Bonaire.

Agaricia grahamae, Graham's Sheet Coral. Looks like thin sheets to thick plates, often as piled up shingles on a sloping reef. Polyps appear star-like in valleys. Septa alternate in size (Lamarck's are equal in size). Bahamas pix. Second pick, Graham's on left, Lamarck's on right for comparison.

Agaricia lamarcki Milne Edwards & Haime 1851, Lamarck's Sheet Coral. Colonies are flat one-faced plates arranged in whorls. Usually brown rust in color with whitish mouths. Belize images.

Agaricia tenuifolia Dana 1848. Thin upright colonies, joined at angles at their base. Corallites in valleys, arranged concentrically with low ridges. Bahamas images.

Family Mussidae Ortmann 1890.

Variously called Meat and Brain corals for obvious common characteristics: large "meaty" polyps, wandering valley-like arrangement of corallites like the sulci of grey matter. All have distinctive thick columellae and corallite walls with toothed septa.

Genus Isophyllastrea

Isophyllastrea rigida, Rough Star Coral, Polygonal Coral. Tropical West Atlantic. Dome-shaped. Ridge along midline of septa. One each in Cancun and Cozumel, Mexico.

Genus Isophyllia Milne Edwards and Haime 1851. Small colonies (typically under eight inches in diameter), flat to slightly dome-shaped. Thin septae and columnellae (on dead skeleton appearance). Found only in the tropical West Atlantic.

Isophyllia sinuosa (Ellis and Solander 1786). Distinctive for its range. Meandering valleys. Not common. Bahamas image.

Genus Mussa Oken 1815. Monotypic, only found in the tropical West Atlantic.

Mussa angulosa (Pallas 1766). Large, fleshy polyps that are well-separated. When retracted, skeletal elements/septa appear spiny. To two feet in diameter. Below: Bahamas images of larger, smaller colonies and a close-up by Di.F in Cozumel.

Genus Mycetophyllia Milne Edwards and Haime 1848. Flad colonies with outward radiating valleys. Poorly developed columellae. Septa-costae are outward facing. Found in the Caribbean only.

Mycetophyllia aliciae, Knobby Cactus, Thin Fungus Coral. Usually found as thin convex plates, with distinctive raised star-shaped polyps. Bordered by ridges that run inward, though less pronounced, common than others of the genus in the region. Bahamas pix.

Mycetophyllia danaana, Low Ridge Cactus Coral. Colonies as flat plates, mounds, domes. Ridges about edge turn to the inside, often crossing center, intertwine (definitive differences from M. lamarckiana in the same area). Occurs in green, brown, gray. Six to fifteen inches across. Bahamas pix.

Mycetophyllia ferox Wells 1973. Colonies mainly as rounded plates, covered with sinuous valleys/mazes. Bahamas images.

Mycetophyllia lamarckiana, Ridged Cactus, Large Cactus, Fungus Coral. Colonies as flat, wavy-edged plates. Ridges fleshy, don't extend to centers. Wide, shallow valleys, usually fleshy. Color variable: browns, greens, grays. 6-12 inches in diameter. Bahamas pix.

Genus Scolymia Haime 1852. Singular, circular polyps. Indistinct walls beneath their septa-costae. These are difficult species to discern one from the other. The three occurring in the tropical West Atlantic may be told apart by the shape of their septal "teeth".

Scolymia cubensis (Milne Edwards and Haime 1849). Septa in 2,3 orders as spikes, pick-shapes. Found in the Caribbean and off of Brazil. Bahamas and Bonaire pix.

Scolymia vitiensis Bruggenmann 1877. Septa slope up from the columellae, costae slope down to the perimeter. Look like fungiids with a depressed center otherwise. One in Fiji, another in an aquarium. Below, two in Nuka Hiva, Marquesas, Polynesia.

Scolymia lacera, Atlantic Mushroom Coral. Tropical West Atlantic. To six inches in diameter, most a couple of inches. Have prominent triangular septal teeth ridges. Cozumel image by Di.F.

Scolymia wellsi, Solitary Disk Coral. Radiating, raised lines on polyp. Occur in greens, grays, browns. Has rough, irregular cylindrical, thin septal teeth. Bahamas pic.

To: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15,

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