Keeping Sea Anemones

Spending almost all of their days entirely anchored to a suitable rock or the sides of their tank, sea anemones certainly qualify as pretty unusual pets to keep, but in many ways they are an ideal first introduction to the marine aquarium.

Fairly undemanding animals on the whole, they can provide an excellent grounding in the basics of maintaining sea water tanks, giving new aquarists the chance to gain some experience before moving on to more specialised and difficult species, if they wish.

However, such is the attraction of sea anemones that some never do and few of even the most experienced of marine aquarium fans can resist having at least one or two in their collection – so be warned, sea anemones can become addictive!

Sea Anemone Species

A number of easily-cared for sea anemone species can be found around our own coastline including:

• Common or Beadlet Anemone (Actinia equine)
• Plumose Anemone (Metridium senile)
• Sandaled Anemone (Actinothoe sphyrodeta )
• Daisy Anemone (Cereus pedunculatus)

Although these animals are native to our shores, actually keeping them cool enough can sometimes be a problem!

For most inhabitants of our northerly waters, a temperature of 18C (65F) should be regarded as the maximum – so cooling things down sufficiently in an aquarium during the summer can often pose a challenge. There are plenty of different types of aquarium thermostats and heaters to keep a tank warm, but little equipment is available to the hobbyist to make them colder. As a result, warm-water anemones are often a simpler proposition.

Tropical fish shops often stock them, principally sold as companions to Clown Fish – which make their homes amongst the anemones quite un-affected by their stinging tentacles. Some of the best know are:

• Giant Caribbean Sea Anemone (Condylactis gigantean)
• Magnificent Anemone (Heteractis magnifica)
• Bubble Tip or Maroon Anemone ( Entacmaea quadricolor)
• Mann's Anemone (Cladactella manni)

Housing Sea Anemones

Housing sea anemones could hardly be simpler, comprising an appropriately sized aquarium tank, aeration, ideally with a filter and with the addition of a suitably rated heater/thermostat unit if you’re keeping tropical species.

A power pump is also a good idea in a large tank helping to circulate the water and setting up an internal current which replicates the movement of the sea. This will allow you to see your anemone’s tentacles waving – and more importantly will help to bring their food to them.

Obviously, whatever type of equipment you use in your aquarium, it must have been designed for salt water.

Unless you live by the coast, you’ll have to make up your own supply of seawater from one of the commercially available salt mixes. Many species of sea anemones, especially those which live in rock-pools close to the shore, tolerate a range of water salinity; they need to – in their natural environment salt levels can be very variable, depending on how much rain falls or how much water evaporates on a hot day. Deep water species tend to be less forgiving, so it pays to know what sort of animal your pet is – and buy a special aquarium hygrometer to make sure you get the salt concentration right.

Feeding Sea Anemones

With the exception of one or two specialist-eaters from tropical waters, all anemones are easy to feed, taking small fresh pieces of seafood, fish, lean raw meat or even insect larvae. As a general rule, the finer the tentacles, the smaller the food should be – though the likes of the tropical Stoichactis species are an obvious exception to this.

Anemones only need to be fed sparingly – and placing the food directly into the path of their tentacles is the most efficient method. Once or twice a week seems to be quite often enough, making sure to remove anything left in the tank which has not been seized upon by the inhabitants after about half-an-hour or so.

Meet their few needs and although sea anemones may seem almost never to do anything, they can be surprisingly rewarding and relaxing animals to keep, often breeding very successfully without making any special demands on their keeper.

Whether you look on them as a stepping stone to more complex sea creatures, or spend the rest of your days addicted to their often beautiful colours and unique appeal, sea anemones are well worth considering for any marine aquarium.