March 23, 2012
We've discovered a snail never before found in L.A.! A few weeks ago, I was wandering through the North Campus and happened upon a tiny gastropod snailing along the Living Wall! Most snails don't catch my attention as they are usually of the common garden variety, aka Brown Garden snails, Helix aspersa. This particular specimen caught my eye, because unlike the Brown Garden snail, this snail was much smaller and flatter (the shell is only 6.9 mm wide). I grabbed the snail, placed it in a vial and took it to our snail expert, Lindsey Groves.
Brown Garden snail, Helix aspersa
Southern Flatcoil snails photographed in Cathedral City (Image courtesy of Patrick LaFollette, Museum Research Associate) Lindsey is the Museum's Malacology Collections Manager and when I showed him the snail, he got pretty excited. Although some people may find this strange, I did not. In fact, I was excited too. What I did find strange was that Lindsey already had another specimen of the exact same species sitting under his microscope at that very moment!
Malacology Collections Manager, Lindsey Groves It turns out that the snail I found is a Southern Flatcoil snail, Polygyra cereolus. According to Lindsey, this species of snail ranges from southern Florida to South Carolina and across much of the Gulf coastal states to Texas, as well as several areas of northeast Mexico. Over the past few of decades, it has become common in other locations such as Wisconsin, Hawaii, and even a number of countries in the Middle East including Qatar, Saudi Arabia, and the United Arab Emirates! These range extensions are attributable to accidental introductions through importation of sod and/or ornamental landscape plants. The specimen that Lindsey was examining under his microscope was recently collected in the Laguna Hills area of Orange County. He is currently working on documentation of this new county record and will also document the snail found on the North Campus, which is now preserved in the Museum's Malacology collection. The snail has also been discovered a bit further afield in Cathedral City, Riverside County.
Top view of Southern Flatcoil snail. Another in a long list of introduced terrestrial mollusc species in our area, 20 to be exact, it is reported that the Southern Flatcoil snail feeds on clover and alfalfa. As such, they have in some instances been reported as agricultural pests, but will likely feed on many other types of vegetation found in parks and gardens. In Florida, they have been observed assembling in large numbers on sides of buildings and walls without apparent regard to sun exposure, which is very unlike many snails. In one building at the University of North Florida, an aggregation of thousands of individuals were found coating the building surface! According to one of Lindsey's colleagues in Florida, "they are like a weed."
Side view of snail. Apparently the characteristic apertural 'tooth' for this genus must have broken off when it was collected.