is a small, slender anemone up to 35 mm in height, usually orange in colour. It has up to 200 tentacles on the oral disc which are also orange in colour but paler than the column. The surface of the column is smooth and is dotted with irregularly spaced pores (called cinclides) that serve to release water from the body cavities when the anemone contracts. When contracted, the body appears distorted and the parapet, a fold of tissue surrounding the tentacle-bearing part of the body (the capitulum), is distinct. When Diadumene cincta
extends, the parapet folds out and becomes indistinct. If disturbed, this anemone extrudes stinging cell-bearing tentacles called acontia through the mouth to deter attackers.Diadumene cincta
may be mistaken for small plumose anemones Metridium senile
as these two species are found in the same habitat. Diadumene cincta
is much more erect and has fewer tentacles than Metridium senile
, which has a dumpy appearance.