Lophelia

Lophelia pertusa, the only species in the genus Lophelia, is a cold-water coral that grows in the deep waters throughout the North Atlantic ocean, as well as parts of the Caribbean Sea and Alboran Sea. Although L. pertusa reefs are home to a diverse community, the species is extremely slow growing and may be harmed by destructive fishing practices, or oil exploration and extraction. Lophelia pertusa is a reef building, deep water coral, but it does not contain zooxanthellae, the symbiotic algae which lives inside most tropical reef building corals. Lophelia lives at a temperature range from about and at depths between and over , but most commonly at depths of , where there is no sunlight. As a coral, it represents a colonial organism, which consists of many individuals. New polyps live and build upon the calcium carbonate skeletal remains of previous generations. Living coral ranges in colour from white to orange-red; each polyp has up to 16 tentacles and is a translucent pink, yellow or white. Unlike most tropical corals, the polyps are not interconnected by living tissue. Some colonies have larger polyps while others have small and delicate -looking ones. Radiocarbon dating indicates that some Lophelia reefs in the waters off North Carolina may be 40,000 years old, with individual living coral bushes as much as 1,000 years old. The colony grows by the budding off of new polyps. Living polyps are present on the edges of dead coral and fragmentation of coral colonies provides one form of asexual reproduction. Each colony is either male or female and sexual reproduction occurs when these liberate sperm and oocytes into the sea. The larvae do not have a feeding stage, but sustain themselves on their yolks and drift with the plankton, possibly for several weeks. When settling on the seabed, they undergo metamorphosis and develop into polyps, which then potentially start new colonies. Lophelia reefs can grow to high. The largest recorded Lophelia reef, Røst Reef, measures and lies at a depth of off the Lofoten Islands, Norway.