MAD'REPORE (from It. madrepora, mother of-pearl, probably from madre, from Lat. ',later, mother Gk. 7r6pos, Taros, passage, pore, or 1-(2,pos, paros, light friable stone). A large branching coral abounding on the reefs of Florida and other parts of the tropics in the Atlantic, Pacific, and Indian oceans. The most abundant species in the West Indies is Madrepora cerri cornis, so called from its habit of growing in bush-like masses nearly two feet high and three to four feet in diameter, the separate spikes or branches resembling the antlers of a deer. It is the most abundant of the true reef-building corals. It grows up to the level of the sea, and then, becoming exposed at low water, the tips of the branches are often killed. It easily breaks when exposed to the waves, as it usually is, and its fragments form a large proportion of the coral sand. which becomes solidified into coral rock. See CORAL, and accompanying Plates.
The madrepore is the most complex of all the corals. Its tree-like form is due to multiplica tion of the small corallites by budding. A coral lite is the individual polyp of the colony sup ported by its coral stock or skeleton. It is a
perforate type of corals, all parts of the coral stock and connecting ccenenchyme (formed by the calcification of the ecenosare or inner layer of the polyp) being like a mesh-work consisting of calcareous fibres arranged like basket-work. and traversed by a net-work of tubes, represent ing the ccenosarc and communicating with the other polyps of the colony. The madrepores do not live in water the winter temperature of which is under 60° F. They abound on the Bermuda Islands in the Atlantic, and as far north as Southern Japan in the Pacific Ocean, while their southernmost limits are Rio Janeiro and Saint Helena in the Atlantic, and Queensland and Easter Island in the Pacific Ocean. Thus they extend to about north and south latitude 30°.
Consult authorities cited under CORAL, and particularly Saville Kent, The Great Barrier Reef of Australia (London, 1893), containing many illustrations from photographs of these and other reef corals.