Freshwater Mussel Identification
Megalonaias nervosa (Rafinesque)
Description: Theshell is large and brown or black in color. It is elongate, thick and somewhat inflated with the front end rounded and the posterior end straight. There are several broken ridges of various sizes (some v-shaped) on the surface of the shell, and it has bumps in the beak area. There is a small wing on the posterior dorsal margin that has several ridges. Nacre is white, but may contain discolored areas. Size: up to 12 inches. Host: Several species. Compare to Pistolgrip and Threeridge.
Amblema plicata (Say)
Description: The shell is large and light to dark brown. It is elongate and somewhat square in shape. with 3-5 (occasionally more) large, continuous, smooth to rough ridges that slant from the upper front margin to the lower posterior margin. There are no ridges on the posterior dorsal margin, and there are no bumps in the beak area, thus separating it from the Washboard. Nacre is white, but may contain colored areas. Size: up to 8 inches. Host: Several species. Compare to Pistolgrip and Washboard .
Quadrula nodulata (Rafinesque)
Description: The shell is somewhat rounded square and inflated. Shell color is yellowish to green or light brown. The anterior end is rounded and the dorsal margin is straight. The Wartyback lacks a furrow (depression) but does have two rows of bumps extending down the shell: the distance between the bumps is greater toward the ventral part of the shell. Nacre is white but may be pink in Alabama and Tombigbee Rivers. Size: up to 3 inches. Host: Several species. Compare to Quadrula and Cyclonaias.
Quadrula quadrula (Rafinesque)
Description: The shell is generally square and somewhat inflated. Color is yellowish-green to light brown and often has several green rays running vertically from the beak. The shell has a defined furrow (groove or depression) in the posterior half. The posterior ridge has several bumps and small broken ridges. Nacre is white. Size: up to 4 inches. Host: Flathead Catfish. Compare to other Quadrula species
Quadrula metanevra (Rafinesque)
Description: The shell is rounded anteriorly, and concave posteriorly along its margin. Color is usually yellow to light brown with dark green triangular markings. The shell has 3 to 5 large bumps on the posterior half surrounded by smaller bumps. The anterior is usually smooth and free of bumps. Nacre is white. Size: up to 4 inches. Host: Green sunfish, bluegill, and sauger. Compare to other Quadrula species.
Tritogonia verrucosa (Rafinesque)
Description: The shell is thick and elongate. Color is light to dark brown with green markings. Anterior end is rounded and the posterior end is pointed or straight (often shaped like a grip on a handgun, hence thc name Pistolgrip). The surface is covered with pustules of varying size and shape (similar to that of a deer"s antler). There is a pronounced lumpy ridge on the posterior end. Nacre is white. Size: up to 8 inches. Host: Unknown. Compare to Washboard.
Ohio (River) pigtoe
Pleurohema cordatum (Rafinesque)
Description: The shell is round to sub-triangular, inflated, thick, and smooth (no bumps). Color is yellow or brown to dark red-brown and black. There are several fine rays present near the beak (they may be hard to see). The posterior end has a furrow or depression. The tip of the beak twists and points toward the anterior end. Nacre is white. Size: Up to 4 inches. Host: Rosefin shiner. Compare to Fusconaia and other Pleurobema species.
Wabash (Lake) pigtoe
Fusconaia flava (Rafinesque)
Description: The shell is usually sub-triangular, smooth (no bumps), heavy and inflated with a noticeable slanted ridge on the posterior end. Color is yellow or light brown to dark brown or black in old individuals. The tip of the beak does not twist and it points toward the ventral margin. Nacre is white. Size: Up to 3 inches. Host: Crappies and bluegill. Compare to Fusconaia and Pleurobema species. A related species in Alabama F. cerina, may have a pink nacre.
Fusconaia ebena (I. Lea)
Description: Theshell is rounded with the beak positioned at the extreme anterior end and directed forward. The shell is usually smooth yellow brown (in small individuals) to dark brown or black in old specimens. The anterior ventral and posterior margins are nearly round. Nacre is white. Size: up to 4 inches. Host: Skipjack and several sunfishes. Compare to other Fusconaia, Pleurobema, and Obovaria species.
Elliptio crassidens (Lamarck)
Description: The shell is heavy, thick, elongate and smooth. Color is usually reddish brown with occasional light yellow-brown areas to black in old individuals. The anterior end is rounded, and the posterior is triangular pointed or only moderately rounded. The posterior end has a ridge, which gets sharper (steeper) as it nears the beak. Nacre is purple. Size: up to 6 inches. Host: Skipjack herring. Compare to Fusconaia and Pleurobema.
Ellipsaria lineolata (Rafinesque)
Description: The shell is thick and triangular. Males are compressed. and females are inflated. Color is yellow to yellow-green with broken green rays (the rays are made up of v-shaped or triangular markings). The posterior ridge is sharp and has a narrow slope. Nacre is white. Size: Up to 4 inches. Host: Green sunfish and drum.
Potamilus alatus (Say)
Description: The shell is heavy, elongate and smooth. Color is light tan to dark green or brown to black with several green rays (often difficult to see). The anterior and posterior ends are rounded, and the ventral margin is straight. The posterior 1/2 of the shell along the dorsal margin is extended to form a triangular wing or heel. Nacre is pink to purple Size: Up to 8 inches Host: Freshwater drum. Compare to Potamilus inflatus.
Obliquaria reflexa (Rafinesque)
Description: The shell is thick, triangular, and has several (usually three) large rounded knobs that alternate w ith those on the opposite side. Color is yellow to yellowgreen or dark brown in old specimens. The shell may have several fine, green, broken rays. The anterior end is rounded and the posterior is pointed. Nacre is white. Size: Up to 3 inches. Host: Unknown.
Corbicula fluminea (Mueller)
Description: Shell small (less than 2 inches) round to triangular. Color is yellow in small individuals to black in larger specimens. Juveniles have a dark purple stripe on the umbo that extends ventrally. The beak is located centrally on the dorsal margin. Nacre is white to purple. Size: Up to 2 inches. Host: Not necessary. Comment: This is an introduced species from Asia.