03 November 2005

Prospecting for snails during lunch break

Exploring the neighborhood for natural history specimens and photographic subjects during my daily walks has become a passion. Last Thursday my walk took me to a local “community” park in College Park. Such places, ordinarily with paved parking lots, regularly cut grass and well-spaced trees with very little leaf litter and almost no deadwood, offer few suitable habitats for ground-dwelling animals. Fortunately, however, I chanced upon a relatively young tree that nevertheless had a large hole thru its base. Tree holes usually harbor snails and other critters and this one was no exception.

In the hole under the wind-blown leaves covering the soil, I found 2 juvenile specimens of Mesodon thyroidus, a common eastern native. As you can see in the picture, this tree was next to a parking lot. Normally, I wouldn't have expected to find any snails in that hole. But what probably made a difference in this case was that the hole was facing a small patch of 2nd growth forest a few meters away. The snails had probably migrated over from the forest.

In previous posts (here and here), I had pictures of adult M. thyroidus shells showing how the lip partially covers the umbilicus. I also mentioned before that in juvenile shells the umbilicus is always open. Thus, being a juvenile, the pictured snail had an open umbilicus. Also notice that the internal organs show thru the semi-transparent shell.
Later on, in a narrow strip of forest separating the “urbanized” park from a small stream, I found, next to a piece of rotting wood, another species of land snail: Ventridens ligera, another native that is perhaps even commoner than the former species. But it refused to come out of its shell for a photo-op.

1 comment:

Goob/Kris said...

How incredibly cool.