There were six of these Bumble Bee snails added and I still see a few.

I find them attractive, they add to the bio-diversity and seem to be harmless.

This is one of my 12 Cerith snails laying eggs last April.

They laid regularly every week or so for a couple of months.

The double line complete it starts on the vertical line.

The complete string. They do not always lay their eggs so neatly as is shown in the double string in the right picture.

In January this year, early one morning, I saw dozens of tiny snails, about ¹/₂cm long. They are the same shape so they could be the result of the spawning.

Conches are herbiverous molluscs which frequently occur among sea grasses. They use their sickle shaped, horny operculum to move in an amusing pole vaulting action.

(Right picture by Lisa Page)

My Queen Conch has grown considerably since I bought it mail order from S.T.M.

It is a favourite with visitors and does a splendid job keeping the substrate clean.

All its time is spent cleaning each grain as it patrols across the sand. Occasionally it withdraws its head and rests for a while and sometimes it will clean a small piece of rock but it has never climbed.

A couple of pictures of the Queen Conch cleaning algae off the red urchin.

A gift from Frank. This conch occurs on shallow sea grass beds with fine sediments.

In my tank it cleans the sand during the day and then partially buries itself at night which helps stir the sand.

After a few days it became apparent that this conche's favourite burial spot was undermining a large Montepora sp. and Echinopora lamellosa group so much that it was impossible to get the algae magnet between the corals and the glass. The conch was therefore banished to the sump.

Another gift from Frank. This is one of the largest conches reaching 40cms long in the wild.

It occurs mainly on shallow reef flats but also on coarse gravel and coral rubble. Here it is obligingly tackling a patch of hair algae that nothing else would touch.

In the picture on the right the horny operculum can be seen sticking out to the right.

I have five of these delightful little conches in the sump where they keep the sand pristine. My sump had been plagued with a complete covering of red slime algae for several months before I added the conches.

As can be seen in the right-hand picture they also clean any glass within reach. They do not, however, climb.

In the wild they live in colonies. These are tank bred and according to Hawkmaster on Ultimate Reef they only grow to about 21/2cm. However according to this web-site they reach 7cm to 14cm. Time will tell!

There are many small snails of this type and I find it impossible to identify mine from pictures.

They are herbivores and they spawn regularly, usually on the glass.

Another successful mail-order purchase of six.

These snails are excellent scavengers which live on carrion. They inhabit the sand bed and help to turn it over. Although mainly nocturnal they have a very sensitive syphon and can smell their food up to 30m away. It is great fun watching them erupt from the sand whenever they sense something tasty. The syphons can be seen in the right picture probing the substrate.

Related toTurbo and Astrea snails these are excellent herbivores which remain small.

They are normally introduced on live rock and readily reproduce in the aquarium

These are sessile snails which are often mistaken for bristle worms, 'Vermes' means worms.

They feed by extending a mucus net to trap detritus and then consume the net, with its catch, by drawing it in. A new net is then extended.

They grow calcareous shells which in my tank have been encrusted by the corals on which they settle. It has become a constant battle between the snail extending its tube and the coral encrusting the tube.

This Millepora sp. shows this to perfection. The main branch on the left is a constantly growing vermitid snail tube and the snail's tentacles can be seen protruding from the end. Where the Millepora sp. has encrusted the growing tube it has put up eight or more vertical branches.

The same process can also be seen on several more branches.

On the other hand the much slower growing Turbinaria has barely started to encrust the snail tube which can be clearly seen in the right hand picture.