Bladder Snail

Physa sp.

Photo Credit: Thomas Everest

Bladder snails are the most ubiquitous snail in the country, and probably the world. They have been spread all over the world by humans, but they are native to North America. The two possible species are the acute bladder snail (P. acuta) and the tadpole physa (P. gyrina); they can only be reliably distinguished with dissection. The specific populations here have not been identified to species, and could be native or introduced. This is the only freshwater snail known from campus, and it is found in the creeks when they have running water. In the drier months, the adults likely die while the eggs survive and hatch during the rainy season.