Reproduction
Corals reproduce asexually, increasing the size of the colony through budding of new polyps. Coral can also reproduce sexually; some species are hermaphroditic while others have separate sexes. The majority of species are spawners, which means they release eggs and sperm into the water column in a spawning event, often synchronised within and/or between species leading to spectacular mass spawning events. Others are brooders, so their eggs are fertilized internally and released into the water column as free-swimming larvae or planulae. This planktonic stage of the life cycle lasts between a few hours to weeks, depending on the species, before they settle on a suitable substratum. Sexual reproduction is critical to allow genetic flow between coral reefs and the establishment of new reefs.
