Introducing Ithaca

Of a pretty big disappointment to me is how much the terrestrial mollusk fauna in the Ithaca area is non-native. I guess, however, this is to be expected in a developed area-- even one that seems like it's known for it's natural areas (Ithaca is Gorges). Still, I'm spoiled by some good snailing back home in PA.

Here are some of the non-native species I've encounted:

Discus rotundatus

Photo by Aiwok: http://commons.wikimedia.org/wiki/File:Discus_rotundatus_2.JPG

Probably the snail I was most pleased to see out of the non-natives only because there are so many Discus Catskillensis where I live in PA. I found some of these near the Equestrian Center in Ithaca (can't remember what it's called, some sort of orchards).


Limax Maximus : Leopard Slug

Photo by Jonathan Feinberg http://commons.wikimedia.org/wiki/File:Leopard_Slug_Somerville_MA.jpeg

As far as the non-native slugs go, this is pretty cool the first time you see it. It's absolutely huge. Another species I've never encountered back in PA. I've found this slug in Sapsucker Woods and Monkey Run.


Trochulus hispidus : Hairy Snail

Photo by James K. Lindsey http://commons.wikimedia.org/wiki/File:Trichia.hispida.jpg

This could be a wrong identity on my part as Trochulus striolatus (Strawberry Snail) as juveniles of this species have periostracal structures as well. I've only found 2 alive and a ton of empties. I'll have to check inside the umbilicus of the many shells I found this week for hairs with a microscope when I go home to PA to see if I can confirm these as T. hispidus. Either way, I've seen Trochulus species at Sapsucker Woods and Salt Point.


Carychium minimum : Herald Thorn

Photo by snailmail http://commons.wikimedia.org/wiki/File:Carichium_minimum.jpg

I only found empties of this snail in stream drift from Buttermilk Falls. However, I read a paper about the snail being naturalized in wet areas around Beebe Lake on the Cornell campus. This is a tiny snail-- somewhere between 1.6mm and 2.2mm.

Other species about:

Cepaea nemoralis- around the Lab of Ornithology. Rose and yellow variants, as well as spiral lined. There may also be C. hortensis mixed in. That or it's some C. nemoralis juveniles reaching to about C. hortensis size and not yet developing the brown lip. I'll have to check harder next year. I tend to gloss over non-native species, not giving them the attention I do natives.
Oxychilus allarius- possibly. Cayuga Heights and near Lab of Ornithology
Arion species- Definitely subfuscus and possibly distinctus. Never pay much attention to ugly Arion slugs.
Deroceras reticulum- another ugly alien slug, everywhere.