Diet

• Cerianthidae are carnivorous, suspension-feeding tube anemones that capture small organisms with their tentacles and nematocysts.

• Food includes zooplankton, small crustaceans, larvae, worms and other small marine organisms suspended in the surrounding water. Some species also consume organic particles and detritus.

• The longer outer tentacles intercept and immobilize prey, while the shorter inner tentacles help move food towards the mouth.

• Cerianthids are generally non-photosynthetic and do not depend on zooxanthellae for their nutrition.

Range

• Cerianthidae has a broad marine distribution, with species occurring in tropical, subtropical and temperate oceans around the world.

• Members of the family occur in the Atlantic, Pacific, Indian and Southern oceans, with individual species often having much more restricted distributions.

• The family is represented in both shallow coastal environments and deeper offshore habitats, so its overall range extends across a wide range of marine conditions.

Habitat

• Cerianthids are primarily associated with soft substrates such as sand, mud and sandy gravel, where they can burrow and construct their characteristic tubes.

• They may occur from shallow coastal and estuarine environments to considerable depths offshore.

• The animal lives within a flexible, parchment-like tube that is buried in the sediment, with only the oral disc and tentacle crown normally extending above the bottom.

• Their tubes are constructed largely from mucus and specialized cnidae called ptychocysts, together with particles incorporated from the surrounding sediment.

Description

• Cerianthids are solitary, elongated anthozoans that superficially resemble true sea anemones but are adapted for burrowing rather than attachment to a hard substrate.

• They lack the adhesive pedal disc characteristic of true sea anemones and instead possess an elongated body adapted for life within a sediment-embedded tube.

• The oral disc bears two distinct rings of tentacles: an outer ring of much longer feeding and defensive tentacles and an inner ring of shorter tentacles surrounding the mouth.

• The tentacles can be extremely numerous and may be white, cream, brown, green, purple, reddish or strongly banded, depending on species.

• When disturbed, the animal can rapidly retract its entire body and tentacle crown into the protective tube.

• Cerianthid tubes can provide habitat for other marine invertebrates, including crustaceans, molluscs and polychaete worms, making them small but important microhabitats within soft-bottom communities.