Anthozoa

Anthozoa is a class of marine cnidarians that includes corals, sea anemones, and sea pens. Its members live only as polyps and have no medusa stage.

Cnidaria: A phylum of aquatic animals characterized by radial symmetry and specialized stinging cells called cnidocytes. Anthozoa is one of the major classes within this phylum.
Scleractinia: An order of stony corals that build calcium carbonate skeletons, including many reef-forming species. Its skeleton-building species create many of the world's tropical coral reefs.
Cnidarian life cycle: The developmental sequence of cnidarians, often alternating between a polyp and a free-swimming medusa. Unlike many cnidarians, anthozoans have no medusa phase in their life cycle.
Coral reef: A marine ecosystem built largely from the calcium carbonate skeletons of reef-forming corals. Reef-building anthozoans create complex habitats that support diverse marine life.
Polyp (zoology): A sessile or slowly moving cnidarian body form with a mouth surrounded by tentacles. Anthozoans retain this body form throughout their life cycle.
Actiniaria: An order of sea anemones, soft-bodied anthozoans that usually live as solitary polyps. Sea anemones exemplify anthozoans without a rigid external skeleton.
Broadcast spawning: A reproductive strategy in which organisms release eggs and sperm into the water for external fertilization. Many reef-building anthozoans synchronize spawning to release gametes into seawater.
Coral reef ecosystem: A community of organisms interacting with the physical structure and resources of a coral reef. The ecology of reef communities depends on the habitat anthozoan colonies construct.
Cnidocyte: A specialized cnidarian cell that discharges a capsule, often to capture prey or deter threats. These cells equip anthozoan tentacles to capture prey and defend against predators.
Alcyonacea: An order of mostly colonial corals, including soft corals, gorgonians, and precious corals. Its varied colonies show that coral forms extend beyond reef-building stony corals.

Linked from 4 pages