Friday 27 May 2011

A blue glass snail

ResearchBlogging.orgWhen lifting a pot to plant out today, I found this Glass Snail. There are four British species, and I think this is Oxychilus draparnaudi, given its relatively large size (a mighty 15 mm). Glass snails are named after their shiny, fragile and translucent shells when alive. After weathering the shells rapidly lose their lustre. Oxychilus shells are rather flat, which makes it easier for them to hide under pots or stones.
Given their small size - and their association with pots, nurseries and greenhouses - it is not surprising that several European Glass Snail species have been inadvertently introduced in temperate or subtropical regions around the world, including New Zealand, Australia and the U.S. and Canada. What perhaps is unexpected is that many Glass Snails, including O. draparnaudi are predators and their diet include other snails and slugs and their eggs, in addition to worms, and dead insects. They have even been reported to eat Garden Snails. When predating on snails, they attack the snail's body first with their radula and when they cannot access more flesh from the outside, they drill a hole on the shell to finish off their meal. The introduced populations, however, can be a threat for the native snail fauna and reductions or losses of local snail populations have been reported in areas with these predatory snails when compared with patches where they were absent in the U.S and New Zealand.

References
Barker, G.M. (2004). Natural enemies of terrestrial molluscs. CABI. DOI: 10.1079/9780851993195.0279. Here.
Karin Mahlfeld, Karin. Impact of introduced gastropods on molluscan communities, northern North Island. here.

4 comments:

Anonymous said...

I found one earlier today and was amazed by the blue color. I can't believe how common they seem to be, as I saw two smaller ones shortly after. After reading this article I found a large snail shell nearby with a hole in it. I always wondered what made holes in snail shells and now I know. Thanks for the very informative article 👍

Anonymous said...

Me and my friend found one In my garden abs were amazed and thought it was quit pretty

Anonymous said...

I have a whole family of them living inside my back porch. Do they lose the shell?

Anonymous said...

Found my 1st one ever in sunderland uk