Slippershell
Alasmidonta viridis (Raf.)

Status: State Threatened (August 1, 1989).

Occurence: Occurs in the Embarrass, Little Suamico, Meeme, Mukwonago, Mullet, Pensaukee, Pigeon, and Wolf Rivers plus Kelly Brook. This species may yet be found to occur in rivers for which there are currently only historical records. See the species map.

Aid to ID: The rhomboid-shaped shells are light yellow, green or brown, sometimes with green rays. They have an armed hinge plate. Anterior and posterior ends are rounded. The beak sculpture consists of coarse loops with an uneven surface. The beak is swollen, but low. Pseudocardinal teeth are triangular, lateral teeth poorly developed. Beak cavity is moderately deep. One of the smallest mussels in the state at 46 mm (1.8 inches) long or less.

Habitat: Usually found buried in sand or fine gravel in shallow water or small streams. Also occurs along lakeshores on a sand bottom.

Management Considerations: Because it inhabits small streams and headwaters, this mussel is particularly vulnerable to siltation and pollution from runoff. Habitat protection and water quality improvements would benefit this species. Increased development along waterways in southeastern and northeastern Wisconsin is of great concern to the continued existence of this species.

The content for this page was originally presented in the Endangered and Threatened Invertebrates of Wisconsin, a free publication available by contacting the Endangered Resources Program.