Tube anemones (Cerianthus sp) are fairly commonly seen in local fish shops (LFS’s). They are different and very attractive. They remind me a little of ‘feather dusters’ in how they live, and also of some fireworks in appearance. The ‘pretty’ fireworks that is, where colourful flames and sparks exit the tube a little way before curving over downwards. There are around 50 tube anemone species in the world.
In the aquarium they should prove to be generally hardy – the usual demands for a quality environment are required. The area in which they are located should not have strong seawater movement because of the long tentacles – it is better if it is fairly weak. The lighting that falls on the anemone should not be strong, but moderate to weak. There is another essential requirement and that is sand for them to bury into. The sand depth should be in the region of 3½” to 4½” (circa 9cm to 11.5cm), though deeper sand does no harm. The sand should be coarse and from coral. Those who do not want a decorative sand bed (the depths given are deeper than the normal decorative 1″ to 2″) could consider using a marine safe plastic box full of sand. The edges of the box would need to spread 2″ to 3 beyond the anemone’s tube edge. This could solve the potential for a dirty sand bed. A deep sand bed (DSB) is constructed of very fine sand and is not really suitable.
The anemone has a long tube which is made up of secreted mucus and sand. It extends down into the sand and forms a home and anchor for the anemone. As the tube is quite slender and pointed, it would be possible for it to come out of the sand, so the anemone can create an expanded tube or bulb at the bottom, which prevents this.
It has been reported that if the aquarist does not want sand in the aquarium a plastic tube is sometimes successful. The plastic should be marine safe and a little wider than the anemone, ensuring that the length is more than adequate. The tube can be placed in the aquarium – between rocks for example – where it will not visually intrude and the anemone put into it. Any plastic showing should be covered in encrusting algae growth fairly quickly and the anemone should hopefully be secure and healthy.
The anemone will be on full display when waiting for food capture. If a threat is perceived the anemone will disappear into its tube at very high speed.
As with other anemones, the tube anemones have defensive/offensive weapons. These are the nematocysts, or stingers, that lie curled like spring loaded barbed harpoons until released. They carry venom and this could cause problems if the aquarist does not exercise sufficient care.
The anemones must be located away from all other corals, colonial anemones etc as the sting is strong and could cause severe damage, even killing neighbours. The tentacles are long and therefore have a long reach. The anemones live singly in the wild and should be kept away from each other. Similarly, the aquarist should not put slow moving and less agile small fish in the aquarium, because if they come into contact with the anemone they are likely to become lunch or be badly stung.
Feeding is straightforward as the anemones will take small pieces of defrosted mussel, shrimp or similar – ensure the food is cut very small. Brine or mysis shrimp could also be target fed. The food just needs to fall among the tentacles. Do not overfeed, two perhaps three times a week is enough.
As with other types of livestock, if the needs of the tube anemone are met then the aquarist will be rewarded with a lovely and ‘different’ display.
The following link has photographs of these lovely anemones.