The birds nest coral is one of the most beautiful species of reef forming corals in the wild. These corals aren’t just eye-pleasing, but they also form large reefs that decorate the marine underwater landscape. This coral is also the first to ever be observed to reproduce via a peculiar and unique method and you can learn more about birds nest coral in thesea.org.
The birds nest coral is a type of stony coral which usually forms thin branches that are arranged in compact bushes. There are many other growth patterns that may vary from one species to another, and these are also influenced by habitat conditions and other factors. For example, corals growing in shallow water may form shorter and thicker colonies, especially if there is strong wave action present. In deeper or more turbid water, these corals tend to form more elongated and thinner branches, so as to reach light easier. This coral can have colors ranging from pink to brown, yellow and cream. The polyps that are part of the colony normally extend only during the night.
Just like many other species of corals, the birds nest coral lives in a symbiotic relationship with specialized algae known as zooxanthellae. These provide nutrients to the coral that are produced via photosynthesis, while the corals offer the algae protection and a home. Perhaps one of the most peculiar reproduction methods seen in corals was seen in this species – polyps of dying colonies were noticed to detach themselves. The detached polyps were then able to reattach themselves to the substrate and form another colony. This type of reproduction has been named polyp bail-out and it is a form of reproduction which occurs as an escape response to environmental stress and threats.
While the polyp bail-out is a form of asexual reproduction, this coral can also reproduce asexually via fragmentation or sexually through brooding. In this sexual reproduction, the polyps host the larvae that develop inside and then, once mature, they are released into the water where they will be able to form their own colonies.
A notable feature of the birds nest coral is that it can show remarkable modification that is caused by certain organisms. Such a modification occurs when the female gall-forming Haplocarcinus marsupialis crab trigger the coral to grow its tips into cups that form a permanent cage around the female, entrapping and protecting it from the outside environment. Here, the female will wait for the smaller male crabs to enter the cage and fertilize the eggs.
These corals live in the Pacific and Indian Oceans, from the Red Sea to the Mozambique and Japan to Australia, where they form extended reefs that decorate the seabed.
While many coral reef-forming species are under threat, this species is not listed as a Critically Endangered. It, however, faces the same threats such as global warming, bleaching and diseases. The birds nest coral is listed in the Convention on International Trade in Endangered Species, and trade is regulated carefully in many parts of the world.