Snakelocks anemone

The commonest anemone on Malta's shallow rock, and the easiest to recognise because it cannot properly retract. Up to two hundred long, wavy tentacles stream out from a short column that is usually hidden in a crack, giving a shaggy, permanently untidy look. The tentacles are grey-green to olive-brown, very often with lilac, violet or rose tips, and a fully grown animal covers 15 to 20 cm of rock. The green comes from single-celled algae living in the tissue, which is why it sits out in bright sunlight rather than hiding.

You will meet it in the first few metres of almost any rocky Maltese entry - Ġnejna, Qawra Point, the shallows at Ċirkewwa and Xatt l-Aħmar, the boulder slopes of Comino - down to about 15 m and rarely deeper. It favours sunlit rock, boulder tops and the edges of seagrass, and often grows in loose groups of a dozen or more.

It is worth two minutes of close looking, because the tentacles are a home as well as a weapon. The little spider crab Inachus phalangium sits under the tentacle canopy immune to the stings, and the elegant anemone shrimp Periclimenes sagittifer, glassy with violet and white markings, picks its way among them. Both are easy to miss until you stop moving and let your eyes settle.