Tube anemones

Two of the three tube anemones found in Britain are special to Scotland. The huge fireworks anemone Pachycerianthus multiplicatus is our most spectacular British anemone, and is a surprising animal to find living in soft mud at the bottom of Scottish sealochs. Arachnanthus sarsi is so rare that it doesn't have a common name, and has only been found in a few places on the west coast. The little burrowing anemone Cerianthus lloydii, on the other hand, is extremely common almost everywhere in Britain, except for parts of the east coast

What are tube anemones?

Tube anemones are the only group of anemones that live in a mucus tube buried in the seabed. The tube is very slippery inside, so the anemone can slide rapidly into it when disturbed, disappearing completely into the seabed. All the tube anemones have two kinds of tentacles - long outer ones and a cluster of much shorter inner ones around a central mouth.

Why are they important?

The fireworks anemone and Arachnanthus sarsi are both Scottish specialities and are priority species for UK Biodiversity Action Plans now taken forward by the Scottish Government through the Scottish biodiversity Strategy 

Fireworks anemone, Pachycerianthus multiplicatus

At up to 30 cm across, with a tube up to a metre long, the fireworks anemone is our biggest British anemone, and one of the most beautiful. Its crown has around 200 long outer tentacles, usually white with pale buff bands. The short inner tentacles may be the same colour, or contrasting yellow, pink or purple. The ends of the long tentacles drift with any slight current, giving them a characteristic kinked appearance. If touched gently, the tentacles each coil up tightly. In Britain, this anemone only lives in deep, soft mud in the most sheltered parts of sealochs, mainly the fjordic type with shallow sills and deep basins inside, at depths of 15-200 m. It also lives off the coast of Norway.

Arachnanthus sarsi

Very little is known about this beautiful anemone, because it is so rare. It has only been found at a few places in western Scotland, including the Firth of Lorn, and in north-west Ireland, in sandy or shelly mud at depths of 10-36 m. It has fewer tentacles than our other tube anemones, with only 30 outer and 30 inner, the latter often held together in a pointed cone. It may be more active at night, like some tropical tube anemones, and this may partly account for how rarely it is seen by divers.

Burrowing anemone, Cerianthus lloydii

The commonest and smallest of the tube anemones, the burrowing anemone has up to 70 long tentacles, with a span of about 7 cm. The colour is quite variable, but the outer tentacles are often translucent brown or opaque white. Some individuals have a beautiful bright green centre. The burrowing anemone lives in a wide range of sediments, from mud through to coarse gravel and maerl, from the lower shore to 100 m depth or more.