22 May 2006

Shell repair in Cerion

Can all terrestrial snails repair their shells? The ability to repair a damaged shell is such a vital requirement that it would be expected to have evolved in all land snails. Since marine snails are known to be able to repair their shells and terrestrial snails have descended from marine ancestors, it is perhaps more accurate to say that none of the terrestrial snail lineages would be expected to have lost their ancestors' ability to repair damaged shells.

Nevertheless, building and repairing a shell is costly and time consuming. Thus, some snail species may have traded off the shell repair ability with rapid growth and abundant egg production.

There are 2 ways to determine if a given snail species can repair damaged shells. First, one may examine shells for scars of repaired damages. I have presented examples of repaired shells here and here. Also check out this paper of mine to see how I used this method to establish that Pomatias elegans can repair its shell. Of course, the lack of scars in a particular collection of shells doesn’t necessarily mean that the snails can’t repair their shells.

Second, if live snails are available and can be kept in captivity in good health, one may remove sections of their shells and then monitor the snails to see if they will repair the breaks. However, the interpretation of the results from such an experiment is not straightforward. A snail that can repair its shell in captivity may not be able to do so in the wild, or vice versa.

I have been cataloging all major scars I come across on land snail shells. My purpose is to determine if there are indeed any species or higher groups that have lost the ability to repair their shells. Here is a picture of a Cerion shell with a scar that is about half a whorl long (arrows).


pascal said...

If I come across other repairs, I'll let you know.


Take pictures.

eped said...

just stumbled on and am digging your blog. intriguing combination of boxcar graffiti, gastropods, beers and aerials. thanks, I'll be back.