Here are some pictures I took of Achatinella mustelina, a rare endemic snail found only in the Wai’anae range.
O’ahu tree snails (Achatinella spp.) are pretty cool because unlike common garden snails,
these tree snails don’t actually eat the plants they are found on. Just ask any gardener; typically it is a battle against snails and slugs that eat their prized plants. I know I have issues with Giant African snails eating my pepper plants (jerks). Instead, Achatinella snails graze on algae and mold that grow on leaves.
Achatinella snails are also known for the beautiful coloration on their shells. This led to over collection. Now dozens of species have gone extinct and many of the extant species are very rare.
As you can see, the actual shell coloration can be quite variable. These are all Achatinella mustelina, even the all white one. If you are wondering, the snails sleep on the underside of leaves during the daytime. They come out to feed when the sun goes down.
The other neat thing is that we found 5 in one tree. Well I thought it was strange: They are so rare that I thought the populations might be more spread out. I can only imagine what it was like 100 years ago when Achatinella were so plentiful that one way to collect them was just to shake a tree and it would rain snails. Boy, would I love to see those population densities happen again.
For more, Nathan Yuen’s blog at hawaiianforest.com has tons of snail information on his observations of them in the field.