Waratah Anemone

When underwater, this sea anemone opens up to display numerous tentacles, arranged in three whorls. Out of water, the tentacles retract and the anemone closes to resemble a dome shaped red, crimson, brown, green or black blob of jelly, about 4 cm (1.6 in) across and 2.7 cm (1 in) high. While in a closed state, the anemone has a soft, ductile and jelly-like exterior. This species was first described in 1898 by H Farquhar who wrote "Full-grown individuals in situations well exposed to the rays of the sun have a column greenish or brownish black, and the disc and tentacles dusky crimson, while those on the undersides of overhanging stones are reddish brown or crimson, the depth of colour varying according to the amount of light which reaches them." Actinia tenebrosa is similar in form to the beadlet anemone (Actinia equina) of the northern hemisphere. The column has a number of iridescent blue spherules armed with nematocysts.

The waratah anemone is found along the coasts of southern Australia, its range extending from Perth to New South Wales. It is also found throughout New Zealand. It is found in cracks and crevices, under overhangs and under boulders on rocky shores, usually in the middle to low intertidal zone but occasionally higher up the shore.