The Caribbean Sea and Adjacent Waters Including Florida, Bermuda, and the Gulf of Mexico
Class Anthozoa (corals, anemones, and relatives), Order Scleractinia (stony corals)
The grooved brain coral is named for its appearance. It looks amazingly like a human brain and has particularly deep grooves that resemble the brain’s folds. In deeper waters, it can even have a grayish appearance. It is a large, reef-building coral that lives throughout the Caribbean Sea and adjacent waters. The grooves may also resemble a maze or labyrinth, giving rise to the scientific name ‘labryinthiformis.’
This species forms large, circular structures that can reach more than 6 feet (nearly 2 m) in diameter. Though they appear to be very large, only the outer few millimeters represent living tissue, while the rest is a calcium carbonate skeleton. Grooved brain coral structures only grow a few millimeters each year and may be hundreds of years old. Each structure is actually a colony of several genetically identical animals living together. These animals are hermaphroditic – each individual produces both eggs and sperm – and reproduce sexually. Sperm are released into the water column and captured by other individuals, which filter feed. Rather than being ingested, the sperm are used to fertilize eggs within the colony. After the egg hatches, a larva is released into the water column. Within a few days, the larva settles onto the reef surface and begins to form a new colony.
Like most shallow-water corals, grooved brain corals have symbiotic algae living within their cells, providing the corals with excess energy that they make via photosynthesis (the use of sunlight to convert carbon dioxide into food/energy). Nearly all species of shallow-water corals and several other groups of reef invertebrates have symbiotic relationships with these algae, so it is important that they live in clear, shallow water. Grooved brain corals also filter feed and eat small zooplankton and other prey from the water column. This food provides them with additional energy and provides their symbiotic algae with the necessary nutrients to continue to generate food.
Though coral bleaching, disease, and pollution all threaten grooved brain coral populations, this species is still relatively common, and scientists believe it to be a species of least concern.