Giant African land snails have invaded Cuba
One of the world’s worst invasive species has reached the Caribbean,
threatening native plants and animals
Presented by Melissa Hogenboom
Imagine the size of a common garden snail. Now multiply it several times.
Now you get an idea of the size of giant African land snails. They can
grow to the size of a rat and are an extremely destructive pest, eating
anything green in their wake.
That’s why they are considered among the worst invasive species in the
Though originally from east Africa, researchers discovered that last
summer that they have now reached Havana in Cuba, a finding they outline
in a new report in Molluscan Research.
That’s an issue, not only for Cuba’s plants, but for Cuban snails.
Most of Cuba’s molluscs don’t exist anywhere else in the world. They are
also extremely diverse, but are now at risk of being outcompeted for
resources by the new invaders.
Once they infiltrate the giant snails can spread quickly. They are
hermaphrodites and can begin reproducing at six months. One snail can
lay 100-300 eggs per month.
“The probability of these eggs hatching is 95% so the species could
eventually cover the whole island,” explains Antonio Vazquez of the
Institute of Tropical Medicine in Havana, Cuba. He is currently
monitoring just how serious the infiltration is.
The researchers do not know when they first invaded or how they got
there. But they expect their numbers to increase, as they are extremely
good at adapting to new ecosystems.
Cuba is not the only place the giant snails have invaded: they have also
reached Brazil, Florida and Venezuela.
It will be hard to get rid of the giant snails, as molluscicide could
damage the indigenous population.
Introducing another predatory snail might seem like another option but
this was done in 1821 in the Hawaiian islands with some unfortunate
consequences. Instead of eating the African giants, they only ate other,
native snails. The African giants, it seems, were untouchable.
So what should Cuba do?
Eradication is too much to hope for, says Vazquez. Instead he wants the
country to control the snails’ population, to stop them spreading too far.
He hopes Cuba’s mollusc surveillance programme will help monitor their
population, and remove individual snails by hand.
But it will be crucial to advise the public not to collect the snails as
pets. They can also pose a threat to human health as they host the rat
lungworm parasite, which can cause a form of meningitis.
Source: BBC – Earth – Giant African land snails have invaded Cuba –