The Assassin Snail (Anentome helena) is a relatively new import to the UK.

As the name suggests, Assasin snails seek out other snails and eat them.  These snails are great if your aquarium is overun with pest snails, such as tadpole snails.  They grow to 1.0 inch in length and are very interesting to watch.  They cruise around the aquarium with their proboscus extended - looking like little elephants! This structure is similar to that found on saltwater welks and are used in a similar way for predation of other shelled creatures.

These snails are 100% freshwater snails, they are tolerant of a wide range of water conditions. As with all snails, they are not tolerant of ammonia or nitrite in the water.  The pH should be over 7, so as to prevent their shells from erroding.

Assassin snails will attack and eat many different species of small snails, but seem to prefer the thin shelled species such as ramshorns and planorbis or tadpole snails.  Althought they relish live snails, they will also accept sinking pellet foods.

Assassin snails will not breed to excess in your aquarium.  Each snail only lays one single egg every month or so.  These eggs are adhered to rocks and ornaments and are often eaten by other tankmates. 

Overall, Assassin snails are an effective way of ridding your aquarium of pest snails without the use of chemicals - a much more natural approach to pest population control.  They are also extremely attractive with their yellow and black banded shells and their inquisitive 'trunks'!