Salamander Mussel
Simpsonaias ambigua (Say)

Status: State Threatened (August 1, 1989).

Occurence: Occurs in the following rivers: Chippewa, Embarrass, Eau Claire, south fork of the Flambeau, Lemonweir, Mississippi, St.Croix, Wisconsin, and the Wolf.

Aid to ID: Shell is yellow or brown, smooth, fragile, elongate, and thin. The anterior end is thicker than the posterior end. The male shell is less inflated than the female. Beaks are slightly elevated and somewhat pointed, directed inwardly and toward the anterior. Beak sculpture consists of three to four double-looped bars. One small pseudocardinal tooth is in each valve and the lateral teeth are indistinct. The beak cavity is shallow. The nacre is bluish-white, occasionally tinged with salmon near the beak and iridescent posteriorly. Length to 2 inches (5.1 cm).

Habitat: Found in medium to large rivers on mud or gravel bars but more common under flat slabs of rock, stones or in ledges of underwater cliff faces.

Management Considerations: Habitat destruction and river pollution have resulted in mussel declines. Protection of habitat and improvements in water quality along with restriction of dredging, impoundments, sand and gravel mining, and navigational improvements would benefit this species. Due to the specificity of the host species, protection of mudpuppies and their habitats is particularly important.

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.