THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Snails in the genus Juga are probably the most commonly collected snails in many waters of the Northwest. However, they are limited to flowing streams with high quality water and thus are not likely to be found in wetlands. Most pleurocerid genera can tolerate high levels of human disturbance, but some species are more sensitive. Pleurocerids have a wide size range. The largest tend to live in the margins and pools of streams, but all sizes can be found in streams and rivers.

Juga are fairly distinctive, with a long conical shell that may be smooth or ridged, and an operculum that has a spiraling pattern of lines on it. They can be rather large, and the mantle where the body meets the shell is simple and lacks a frilly edge, although this is unlikely to be visible in preserved specimens. Generally, Juga shells are dark reddish-brown to black and may have lighter colored lines spiraling with the coils.

Size: large
Identifying feature(s): very common and often abundant; usually reddish brown with a well developed cone-shaped shell that may have ridges; tiny to quite large
Habitat: high quality streams and rivers
Tolerance: tolerant and sediment tolerant