Brain Root Coral

Lobophyllia corymbosa, commonly known as lobed cactus coral or brain root coral, is a species of large polyp stony coral belonging to the family Lobophylliidae. This coral is typically found in shallow waters on reefs in the 🌊 Red Sea, off the coast of East Africa, and in various locations across the tropical Indo-Pacific region.

Lobophyllia corymbosa exhibits two distinct growth forms, either forming flat sheets or hemispherical domes. While its diameter is typically below 50 cm (20 in), larger specimens can be several times that size, particularly in the 🌊 Red Sea. The individual lobes of the coral are connected at their bases and measure 15 to 30 cm (6 to 12 in) in length and 5 to 10 cm (2 to 4 in) in width. The coral's polyps are large and each secretes a corallite, which is a stony cup surrounding the polyp. These irregularly shaped corallites form the coral's skeletal structure. Within each corallite, there is a noticeable wall, and numerous radiating vertical ridges known as septa. These septa are narrow inside the corallite but grow thicker and longer on the walls, giving the coral a prickly appearance. The corallites themselves generally resemble an hourglass shape, containing thick and fleshy polyps. During the daytime, the polyps are usually retracted, but they extend their tentacles at night to feed. The polyps vary in color, ranging from bluish or greenish-grey to yellowish-brown. This variation in color is due to the presence of zooxanthellae, minute symbiotic dinoflagellates that reside within the coral's tissues. These photosynthetic algae utilize sunlight to produce organic compounds, which the coral utilizes as part of its nutritional requirements.

The 🌊 Red Sea serves as the type locality for Lobophyllia corymbosa. This species is also found in the tropical 🌊 Indian Ocean and the central and eastern 🌊 Pacific Ocean, typically at depths of up to 40 meters (130 ft). Its distribution extends to western areas such as 🇲🇿 Mozambique, 🇲🇬 Madagascar, the 🇸🇨 Seychelles, Réunion, 🇲🇺 Mauritius, Aldabra (🇸🇨 Seychelles), and Chagos (🇮🇴 British Indian Ocean Territory). Additionally, it occurs in eastern regions including 🇦🇺 Australia, 🇮🇩 Indonesia, 🇯🇵 Japan, and the 🌊 East China Sea. Lobophyllia corymbosa is commonly observed on upper reef slopes, although its abundance varies across different locations. It is worth noting that Lobophyllia hemprichii, a closely related species, is more prevalent than Lobophyllia corymbosa in some areas.