Aquarists at Bristol Aquarium are enlisting the help of tigers to hunt down unwanted visitors.

The ‘tigers’ in question are actually a colony of 20 killer tiger snails from south east Asia which have been brought in to control the numbers of pest snails in several freshwater displays.

Also known as assassin or bumble bee snails, due to their brightly striped markings, the tiger snails have been introduced into the aquarium’s piranha, blind cave fish, angelfish and Amazon displays.

Bristol Aquarium curator, Dan de Castro, said: “Another common name for this species it the ‘snail eating snail’ and that is pretty much exactly what they do.

“They have the ability to swallow other snails out of their own shells and leave behind an empty shell with nothing in it.

“The tiger snails will help to reduce the population of tadpole snails in the displays which are threatening to take over and damage the plant life and, potentially, the entire ecosystem of the displays.

“The great thing about using tiger snails to reduce numbers is that it’s a natural process and means we can minimise the amount of human intervention and disturbance to the displays,” he added.

In the past the snails would have to be removed by hand and, as well as disturbing the fish, this could potentially increase the risks of accidentally introducing chemicals and other substances into the displays.

“We’ve only had the snails for just over a week and we’re already seeing major reductions in plant damage in all four displays,” said Dan.

“As well as eating other snails, the tigers also eat detritus and other waste which helps to keep the tanks clean.

“However they do not eat plants or other invertebrates and, because they reproduce much more slowly than the tadpole snails, they will never overpopulate the displays,” he added.