Wednesday 26 July 2006

Shelled stalkers

Not all snails are vegetarians*. I've already talked about the Otway black snail (Victaphanta compacta) and its carnivorous kin in the Gondwanan family Rhytididae. But they aren't the only shelled killers. Plenty of snails feed on other animals.

This is an Oleacina from Cuba. As you can see, it's sharing dinner—another snail—with a bunch of free-loading flies. Still, it looks as if there's more than enough to go around.

Euglandina is yet another carnivore. Members of this American genus were introduced into tropical areas to combat the problem caused by the giant African land snail Achatina fulica. You can see what's coming, can't you? Euglandina wasn't particularly fond of the African snails. Too big, maybe. Or too tough. They turned their attention to smaller local snails. Thanks to that ill-conceived attempt at biological control, many species of endemic tree snail in the Pacific Islands have been nudged towards the brink. Others have gone right over the edge.



*That reminds me of a Jimeoin line about how he opened the letterbox to find a snail was grazing away on his mail. 'No!' he said to the mollusc. 'It's lettuce.'