Due to the slow life cycle and deep-water habitats of black coral, little is known about their life cycle and reproduction. As with other cnidarians, the life cycle of these corals involves both asexual and sexual reproduction. Asexual reproduction (also known as budding), is the first method of reproduction used by a black coral during their lifespan. Once a polyp is anchored, it builds a colony by creating a skeleton, growing new branches and making it thicker, similar to the growth of a tree. This method of growing creates "growth rings" which can be used to estimate the age of a colony. Asexual reproduction can also occur if a branch breaks off and a replacement is needed. Though light is not required for growth or development, mature colonies will grow towards light. Why they do so is unknown.