Corals are marine invertebrates in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.


A coral "head" is a colony of myriad genetically identical polyps. Each polyp is a spineless animal typically only a few millimeters in diameter and a few centimeters in length. A set of tentacles surround a central mouth opening. An exoskeleton is excreted near the base. Over many generations, the colony thus creates a large skeleton that is characteristic of the species. Individual heads grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon.

In Walking with... SeriesEdit

Walking with DinosaursEdit

Cruel SeaEdit

This episode takes place on and around Jurassic coral reef - an especially important place for Ophthalmosaurus pups, which hid there from the sharks.

Walking with BeastsEdit

Whale KillerEdit

The female Basilosaurus encounters a pod of Dorudon near a coral reef in a lagoon.

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