Metridium farcimen is a large sea anemone, occasionally reaching a height of one metre (39 in) when fully extended. More usually it is 50 cm (20 in) or less in height but is very variable in shape. It can retract its tentacles and form a ball up to 25 cm (10 in) in diameter. The column is slender, smooth and studded with acontia. These are openings through which thread-like nematocysts from inside the body wall can protrude. There are no tubercles and the column is topped by a parapet. The oral disc is lobed and deeply convoluted at the edge and bears well over 100 fine, short, tapering tentacles. The colour is generally opaque white, but orange, salmon and brown specimens sometimes occur. Large specimens have been seen to have long, thick, fighting tentacles, used to drive away other anemones trying to settle too close. In large colonies that all emanate from one individual by cloning, individuals on the edge of the colony may have several of these fighting tentacles on their lips which they use to repel other, non-clonal anemones. Metridium farcimen might be confused with Metridium dianthus which occupies the same habitat and has a similar colour and form, but that species seldom exceeds 10 cm (4 in) in height, has fewer than 100 tentacles and has an unlobed oral disc. Reproduction takes place with the liberation of eggs and sperm from the gonads embedded in the body wall which are then ejected through the mouth. Fertilised eggs de...Learn more about Giant Plumose Anemone