Page 197 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Plagiola elegans (Lea, 1831), Simpson 1914; Isely 1925
Truncilla truncata Rafinesque, 1820, Isely 1925; Murray and Leonard 1962;
Valentine and Stansbery 1971; Johnson 1980; Branson 1984; Oesch 1984;
Turgeon and others 1988; Williams and others 1992; Vidrine 1993;
Watters 1995; Howells and others 1996
Description:
“Shell subrhomboid, solid, inflated, with a very sharp posterior ridge, behind
which it is decidedly truncated; beaks high and full, turned forward over a small lunule;
region of the beaks and upper part of the shell decidedly flattened; central base of the
shell full; posterior point sharp, elevated considerably above the base; surface with
irregular, subsulcate growth lines; epidermis dull or somewhat shining, often having
wrinkled loops behind, yellowish-green with numerous wavy, often broken rays.
Sometimes in addition to the rays there are numerous wavy or zigzag lines and
occasionally the shell is tawny or reddish and rayless; hinge line curved; pseudocardinals
ragged, two in the right valve and one in the left, sometimes they are much split up; left
valve with two laterals; right valve with one and sometimes a faint second one below it;
beak cavities not deep; muscle scars impressed; nacre bluish-white, white, salmon or
reddish. The form of the shell is quite variable and those of the female and male differ
but little from each other. The female shell is a little more produced at the central base”
(Simpson 1914, p 307).
Hosts for Glochidia:
Freshwater Drum, Sauger (Watters, 1994).

Table 38. Summary of T. truncata shell characters.

Maximum
H/L Range Mean H/L Length W/L Range Mean W/L
Location N (%) (%) (mm) (%) (%)
Red River System
Blue River 2 70.1-72.8 71.5 73.2 48.7-61.1 54.9
Boggy River 3 74.7-78.9 76.3 72.2 48.2-50.1 48.9
Kiamichi River 38 66.7-85.6 76.1 72.2 39.8-63.0 48.1
Little River 7 66.4-81.8 72.6 52.0 49.2-55.4 51.8
Glover River 2 71.4-77.2 74.3 49.6 49.6-50.2 49.9
Mountain Fork River 1 81.9 - 65.1 61.3 -
Arkansas River System
Poteau River 3 74.7-83.4 79.9 56.0 45.7-57.7 51.8
Illinois River 8 66.7-79.4 74.6 63.1 48.9-59.3 53.7
Caney River 3 74.2-80.3 77.9 55.0 46.1-54.7 51.2

General Distribution:
Mississippi River system, part of Great Lakes drainage and Gulf of Mexico
tributaries west through eastern Texas.

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