Page 43 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Cyprogenia aberti (Conrad, 1850), Simpson 1914; Isely 1925; Murray and
Leonard 1962; Johnson 1980; Branson 1984; Turgeon and others 1988
Description:
“Shell of medium size, seldom exceeding 80mm in length. Outline usually
rhomboidal, occasionally rounded triangular. Valves slightly inflated, thick and heavy.
Anterior end regularly rounded; posterior end subtruncate. Ventral margin more or less
rounded, tending to be straight or slightly concave posteriorly. Dorsal margin slightly
convex forming a more or less distinct angle with the almost vertical, sometimes
concave, posterior margin. Hinge ligament rather long. Posterior ridge well developed,
high and narrow at the umbonal region, becoming flattened and somewhat double, with a
wide shallow groove before it. Posterior slope with a radial furrow, very narrow. Umbos
low and compressed, curved forward over the lunule, located at the middle of the shell or
somewhat anteriorly. Surface of the shell with strong, low, more or less numerous,
concentric ridges; in addition it is sometimes subvertically wrinkled and nodulous.
Periostracum scarcely shining, yellowish green, with dots and flecks of dark green which
fall into broad broken rays. Hinge very broad and flat. Left valve with two heavy,
triangular, blunt and ragged, pseudocardinal teeth of about equal height; also with two
short, very low lateral teeth.
Right valve with one large pseudocardinal, sometimes with a feeble one on each side of
it. Interdentum is very broad. One low double or triple lateral tooth. Umbonal cavities
are very shallow and compressed. Anterior and posterior adductor muscle scars and
pallial line are all well impressed. Nacre is white, thinner and somewhat iridescent
anteriorly” (Johnson 1980, p 134).
Hosts for Glochidia:
Goldfish (Watters, 1994).
Comments:
Probably extirpated from Oklahoma.
General Distribution:
Black River, White River, Arkansas River, St. Francis River and Meramec River
systems of Arkansas, southern Missouri, southeastern Kansas and northeastern
Oklahoma.
Oklahoma Distribution:
This species was originally described from a specimen collected at Chambers
Ford on the Verdigris River in 1849 by Dr. Samuel Woodhouse. There are no recent
records for the species in the state and is presumed extirpated from Oklahoma’s part of its
range.

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