Freshwater limpets
Ferrissia spp. · Aquatic life
Whole animal · Photo: Letizia Weichgrebe / CC BY
Also called Ferrissia, Creeping ancylid, Fragile ancylid, Ancylids
How to identify Freshwater limpets
- Tiny shell shaped like a cap or tent, about 1/8 to 1/4 inch long
- No coil; tip of the shell points toward the rear
- Thin, tan to gray and see through
- Clings tightly to plant stems, rocks, shells, docks or trash
Similar species
Small fingernail clams have two shells. The shortface lanx (Fisherola) of the Snake and Columbia Rivers is larger, up to about 1/2 inch, and lives on boulders in strong current.
Profile
| Season | Present all year; numbers build in summer. |
|---|---|
| Starts | Breed as water warms in spring and summer |
| Depth | Shallow plant beds and hard surfaces |
| How it spreads or reproduces | Carried on plants, birds and equipment |
| Habitat | Stems and leaves of water plants, rocks, wood and debris in ponds, lakes and slow streams. |
Why it matters in a lake
Harmless algae grazers that are easy to miss. Finding them on plant stems is a sign of a healthy community of small invertebrates.
Where it is found
- Idaho: Occasional
- Oregon: Occasional
- Wyoming: Occasional
Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Mollusca |
| Class | Gastropoda |
| Order | Hygrophila |
| Family | Planorbidae |
| Scientific name | Ferrissia spp. |
Pond snails
Physid snails
Ramshorn snails
Fingernail clams
Floaters (native mussels)
Western pearlshell
New Zealand mudsnail
Asian clam
Chinese mystery snail
Red-rimmed melaniaNeed a hand?
Found it in your lake?
Send us a photo and we will identify it and tell you what it means for your lake.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596