Endangered Resources Program Species Information
Salamander Mussel (Simpsonaias ambigua)

Overview

Species Overview

Salamander mussel (Simpsonaias ambigua), a mussel presently listed as a Federal Species of Concern and Threatened in Wisconsin. In Wisconsin, this species is only found in mud, silt or sand substrates beneath medium to large-sized flat rocks and undercut ledges, where its host, the mudpuppy frequents. It occurs in both the Mississippi River and Lake Michigan drainages. It can be very abundant locally, but extremely rare otherwise.

Status and NHI Documented Occurrences in Wisconsin

The table below provides information about the protected status (State and Federal Status) and the rank (S and G Ranks) for Salamander Mussel (Simpsonaias ambigua). See the Working List Key for more information about the abbreviations used. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. For invertebrates, dots depict locations from the "Invertebrate Atlas," a database with occurrences of rare and common aquatic and select terrestrial invertebrate species found in Wisconsin and adjacent areas. While the invertebrate atlas is a quality assured database, not all records have been verified. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Summary Information State Status: THR Federal Status in Wisconsin: none State Rank: S2S3 Global Rank: G3 Tracked by NHI: Y Species of Greatest Conservation Need: Y

Detailed Information

Identification: 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.

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

Phenology: The salamander mussel is host specific. Glochidia have only been found on mudpuppies (Necturus maculosus) from October through May.

Management Guidance: 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.

Information compiled from publication PUB-ER-085-99 (now out-of-print).

Photos

Click on a photo to view a larger version. Please considering donating your photos to the Endangered Resources Program for educational uses. See also information regarding use of photos

Photo by Lisie Kitchell, WDNR.

Related Links

Links to Additional Salamander Mussel Information

• Michigan Natural Features Inventory [Exit DNR]
• MN Department of Natural Resources [Exit DNR]
• Illinois Natural History Survey [Exit DNR]

Other Links Related to Mussels and Clams

• Illinois Natural History Survey [Exit DNR]
• The Field Museum [Exit DNR]
• Conchologists of America [Exit DNR]
• EPA Biological Indicators of Watershed Health [Exit DNR]
• Milwaukee Public Museum [Exit DNR]