Fluted-shells are named for the obvious bumpy ridges that run down their posterior slope.
- Size: Length up to 7 inches
- Shape: Elongate and ovate. Valves are thick, and compressed with ridges or “flutes” on the posterior slope. The dorsal and ventral margins are straight to slightly curved.
- Periostracum: Dark brown to greenish brown with occasional green rays on younger specimens. Older specimens tend to be more brown.
- Lateral Teeth: Poorly developed.
- Pseudocardinal Teeth: Present. The right valve has one (occasionally two) triangular and smooth pseudocardinal tooth, while the left valve has 2 fused teeth that are difficult to define.
- Nacre: Blue-white, tinged with cream or salmon-colored at the beak cavity, and iridescent at the posterior end.
- Similar Species: Creek Heelsplitter
- State and Global Rank: S2 G5
- Vermont Endangered Species Law: Endangered
- Vermont Wildlife Action Plan: Species of Greatest Conservation Need
- U.S. Endangered Species Act: not listed
The fluted shell is found in medium to large rivers, often in riffles and runs. Substrates it inhabits includes sand, mud, or fine gravel in areas with slow to moderate flow.
Bowfin, carp, northern pike, bluegill, largemouth bass, yellow perch, walleye
In Vermont, the fluted-shell is found only in tributaries of Lake Champlain. This is another of the Mississippi Basin species that reaches its northeastern range limit in the Lake Champlain drainage. Most records of this species are from downstream of the principal fall-lines, but on Otter Creek, the fluted-shell is found as far up as Cornwall. It has not been recorded in Lake Champlain or other lowland lakes or ponds. It is often found in association with other mussel species, and is not found in large numbers.
Distribution map has locations where this species has been documented and digitized into the atlas database. Systematic surveys have not been conducted for many species and those surveys that have been conducted have been largely focused on endangered species. Therefore, in some cases, the actual distribution of freshwater mussels may be more extensive than what is presented here. Shaded areas are watershed sub-basins and river main stems are shown.