Tube anemones look similar to sea anemones, but belong to a separate subclass called Ceriantipatharia. They are also known as tube-dwelling anemones or cerianthid anemones.
Cerianthids are solitary creatures, and are typically quite small, averaging around 5 centimeters (2 inches) in diameter. They can live at depth, and are often found below 40 meters (130 feet).
These invertebrates live on soft sediment substrates in a fibrous tube composed of secreted mucus and threads of specialized stinging cells called ptychocysts. The anemone withdraws into the tube when not feeding or when disturbed.
Tube anemones have a crown of tentacles with two whorls of different-sized tentacles that give them a flower-like appearance.
The ring of larger tentacles on the outside extends outwards with stinging cells to aid food capture and defense. At the anemone’s center is a ring of smaller, more erect tentacles used to manipulate and ingest food.
Cerianthids are active predators, and eat planktonic prey. You can watch one feeding in this video.
Matthew Oldfield is a freelance photographer based in Bali, Indonesia, specializing in editorial and documentary images from both above and below the waves. He works primarily with charities, NGO’s, and other organizations working to conserve the environment, endangered species, and disappearing cultures.
