Connecticut Department of Energy & Environmental Protection

Emergency Burn Ban In Effect 10/26/24 - An emergency burn ban is now in effect for all Connecticut State Parks, Forests, and Wildlife Management areas, prohibiting the use of all outdoor grills, firepits, and campfires, and the kindling and use of flame outdoors. DEEP and local agencies are working to contain several active fires across the state. Please avoid all affected State Parks and Forests, as well as the blue-blazed Mattabesett Trail. The Enduro Trail in Voluntown and portions of North Stonington within the Pachaug State Forest are closed at this time. Please note that today's forest fire danger report remains at an 'extreme' level. More information about the current fire danger, burn ban and recommended safety measures can be found here

Eastern Elliptio

Elliptio complanata

Key Features

Size: Up to five inches.

Shape: Highly variable, but most often subtrapezoidal or subovate. Valves heavy, strong, and laterally compressed.

Periostracum: Color tan (juveniles) to dark brown or black (adults). Shell rays may or may not be present.

Lateral Teeth: Present. Two on the left valve and one on the right valve.

Pseudocardinal Teeth: Present. Two on the left valve and one on the right valve.
Nacre: Color usually white, rose-colored, or purple, and is often discolored.

Often Confused With ... Eastern pearlshell or creeper. Rayed specimens may sometimes resemble eastern lampmussels.

External shell of Eastern Elliptio

External shell

Internal shell, right valve of Eastern Elliptio

Internal shell, right valve

Hinge teeth of Eastern Elliptio

Hinge teeth

Range map of Eastern ElliptioHabitat: The eastern elliptio is found in virtually any large pond, lake, stream, or river, where it is nearly always the most abundant mussel species. It can be found in all types of substrates.

Range in Connecticut: Statewide.

Conservation: The eastern elliptio is the most abundant and widespread freshwater mussel in northeastern North America. Its ability to parasitize a variety of different host fish, inhabit both flowing and standing water, and withstand many forms of habitat disturbance and environmental pollution have made this species so common. It often greatly outnumbers all other mussel species, and may comprise the largest proportion of animal biomass in many lakes and rivers, often far exceeding the combined biomass of other invertebrates and fish. It is a staple food item for muskrats and otters.

Freshwater Mussel Fact Sheets

Eastern Pearlshell
Dwarf Wedgemussel
Triangle Floater
Brook Floater
Creeper
Eastern Elliptio
Eastern Floater
Alewife Floater
Eastern Pondmussel
Tidewater Mucket
Yellow Lampmussel
Eastern Lampmussel

The Freshwater Mussels of Connecticut

Content last updated on January 29, 2014.