05 April 2011

The return of Neohelix albolabris

The largest northeast North American land snail, Neohelix albolabris, lives in the park near my house. But live individuals are hard to come by and even their empty shells are not abundant. The last time I found Neohelix shells was more than a year ago.

Today I was lucky. During the afternoon walk, I found 9 shells within about 10 minutes and I wasn't even looking for them.

The shells were in 2 batches of 4 and 5 shells, respectively, separated by about 100 m. These were the ones that were exposed on the ground. Had I searched under the leaf litter, I might have found even more. I don't know if these aggregations of shells represent the locations of snail colonies or just a coincidental exposure of shells.

The funny thing was that at one of the Neohelix locations there was also an oyster shell.

This was probably a dinner discard from one of the nearby houses. The nearest seashore where oysters may be present is quite far.

1 comment:

Anonymous said...

The oyster shell may have been a needed source of calcium carbonate that allowed the colony to thrive. (I assume that where there was one, there probably were more.) Without limestone rock, the snails may attack dead snail shells for the calcium carbonate for their own shells. You may want to examine the oyster for scrape marks from the gastropods.