Snails and Algae

Most of us would not consider Snails and Algae to be all that interesting, and I guess that my writing about them after all of the other topics is some indication of agreement on my part. On the other hand...

Here you can see some of the kinds of algae which appear spontaneously in the tank. I started out with bare live rock and a few weeks later all kinds of algae were present. Small "trees" appear, like those on the left. Films of algal "goo" appear with bubbles trapped inside them, like those in the center. And long strings of algal "goo" form, like those on the right. Colors range from green to rust to red to purple. It's all a normal part of the tank biosphere, so long as there is not too much of it. I'm not sure exactly what "too much" means in this context.

Here is a Turbo (or maybe it is an Astra) snail, taken with the Mavica, through the glass. He is actually about 3/4 of an inch long, but with this highly magnified picture, you can even see his "teeth". The antennae are also obvious. Without a snail's help, the algae must be rubbed off of the glass with plastic "wool", so his teeth are formidable.

Here is what a snail can do to an algae covered rock in a day or so. Eventually 10 of these snails ate almost all of the algae from the initial "bloom", leaving bare rock behind. All of the green you see is algae; all of the "white" is bare rock.

Here is a lone snail. Notice the algae-generated bubble of oxygen atop his shell. You can just make out his antennae to the lower right of his shell.

Another shot of a lone snail, this time with antennae to the left. He is still covered with algae, but the rocks are now more or less bare. The purples you see is encrusting coraline algae, a sign of tank health. A strong current of water (like from a hand, or a turkey baster [an aquarist's right hand]) will strip the mat of algae off of a surface like a snail shell. In the "wild", these kinds of mats might be uncommon, due to ocean currents. On occasion, the Sally Light Foot Crab will feast on the algae on the snails' shells.

Eventually, a snail found its way to the black plastic sheet which is my overflow partition. You can see the trails he made as he ate algae for a day or two.