Anemones are strange creatures. While they look as if they are quite solid (well, ok, made of jelly), they are in fact mostly water. I mean this not in the sophisticated sense that we, too, are mostly water, but in the trivial sense that they are really a sack of skin which they inflate with water. Prick them and they will deflate (in theory: I've not tried this).

Their "skin" is very simple and thin, and the muscles within the skin layer are responsible for the control of their shape. They can shrink and grow their "foot" and wave their tentacles. They can even roam around the tank (albeit slowly). My Pacific Anemone actually dug a hole in the sand in which to live: it took about an hour or so.

They have a central stomach with a single opening which is both mouth and ... er ... well ...

It looks as if their tentacles are being pushed around by the water, but in fact their tentacles are entirely under their control. If you touch the tip of a tentacle with your finger, it sticks to your finger. As you pull away, the tentacle stretches, until it finally snaps back. At that point, the tentacle is drawn rapidly towards the mouth, under the presumption that some food is coming. Some anemone tentacles sting, but they did not sting me.

I had my first real scare the morning after I purchased my first anemone, a cheap and hardy "Atlantic Anemone". This is what it looked like when I woke up in the morning:

A few hours later, it was much more glorious, as in the following:

Note the slight dimple (actually a bulge) on the surface: this is the "mouth" opening.  At first I thought that this pattern of "full" vs "empty" was related to time of day and/or illumination (I run lights on a timer), but in fact the status of this anemone seems to be more random than anything else.

Here it is again, in a different mood: notice the tall and strong foot, and the wildly waving tentacles.

Here, the foot is not only tall, but broad:

And here it is in a few other moods:

Here, it is expelling something which had been food just an hour before...

You can clearly see the mouth opening in the first photo.

Sometimes I think that it "gets small" as part of its excretory functions.

Here, it almost looks like a sun flower!

I hope you enjoyed this: next time I'll show you photos of my Pacific Anemone.

The Pacific Anemone co-exists with a Clown Fish: they are a very cute pair!