Saturday, August 9, 2008

Snails again...

More about our land snails...


"The white-lipped snail (Cepaea hortensis) and the grove snail (C. nemoralis) are very closely related. The two species share the same habitats, although the range of the white-lipped snail extends closer to the Arctic in Northern Europe.

The white-lipped snail is very slightly smaller than the grove snail, but shares the same variation in shell colour and banding. The two species can mate and reproduce.

The principal difference between them is that the grove snail has a dark brown lip to its shell, while the white lipped snail has a white lip. However, this distinguishing feature is not entirely reliable as there is at least one morph of the grove snail which also has a white lip."

From the University of Paisley Biodiversity Reference

"C. nemoralis is slightly the larger of the two when mature, and it characteristically has a dark lip to the shell.
C. hortensis typically has a white lip to the shell and shows a preference for slightly damper places.

These differences are not, however, reliable, and C. nemoralis has an uncommon white-lipped morph. Their identities can be confirmed only by dissection. They commonly occur together and, consequently, these photographs represent individuals named on a basis of probabilty.

This morphological similarity between the species has implications for the many genetic studies of wild populations - identifications are unreliable when based on shells alone."

FYI: The definitive answer is to be found by a careful comparison of the snails "love darts."

Hope this both satisfies and stimulates your curiosity.

Tomorrow: The 37 inch bass I caught on my boat after class today!

1 comment:

Jackie said...

I would just like to note that during the initial snail observations, I thought we were dealing with one species that displayed 2 phenotypes. Although we sorted the snails into more than 2 groups, I still only observed 2 color morphs. I did not take the number of stripes into account, just the shell color. I had mentally divided them into a yellow group and a mocha brown group. I figured they were the same species and just evolved different color schemes as a way to avoid predation. And keep me posted on the little black snail. I'd be curious to see if Ann and Shashanna discovered a new species!