Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the …

May 22, 2026 · Coral, any of a variety of invertebrate marine organisms of the class Anthozoa that are characterized by skeletons—external or internal—of a stonelike, horny, or leathery consistency.

This tutorial is an overview of the biology of and threats to coral reefs, as well as efforts being made to conserve and protect them. It includes images, animations, and videos.

Corals are small marine animals. The “hard” type of coral grows with the help of algae, which gives it color and nutrients that help it form a sturdy, stony skeleton. Reefs, which form through the …

Nov 22, 2021 · Corals form true reefs when they grow close together and deposit layer after layer of limestone, several feet high. Many different kinds of fish depend on coral reefs for food and …

At its core, a coral is an invertebrate animal belonging to the phylum Cnidaria, which also includes jellyfish and sea anemones. Each individual coral is a small, soft-bodied polyp, typically cylindrical in …

Corals are in fact small animals, called polyps, in the shape of sea minnows that can form colonies. These polyps make a common skeleton which for some species become the foundation of a coral reef.

Coral organisms are called polyps, which are very small and soft animals related to jellyfish and sea anemones. Coral polyps are cylindrical shaped, with a mouth at the end that’s surrounded by barbed, …

On the ocean floor, corals provide commercially and recreationally caught groundfish and other marine life with shelter, protection from strong currents and predators, and important areas for feeding, …

Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.