Cerianthus filiformis (Tube anemone)
Fairly large anemones in a wide array of colors. They form a hard tube through a filamentous secretion in which they can withdraw upon danger, that can be up to 64cm long. The tube is often covered in shell fragments, sand grains and debris. They do not have a pedal disc to move around, unlike other anemones. The outer ring of tentacles are long and tapering. The tube is flexible and the anemone can extend its tentacles a surprisingly long way. The inner ring of tentacles surrounds the central mouth and assists in pushing food inside.
Common.
Indo-Pacfic. It is found near coral and rocky reefs on soft, sandy and muddy bottoms in a depth range of 0-20 meters.
–
Up to 20cm.
They feed mainly on plankton, but can digest much larger prey, such as fish, if they are lucky enough to catch it in their tentacles.
Tube anemones can retract their soft tentacles very quickly to protect itself from grazers due to well-developped longitudinal muscles inside their tubes. It may take a while for the tentacles to reappear because those muscles are less developed.
