Page 188 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Tritogonia tuberculata (Barnes, 1823), Isely 1925
Tritogonia verrucosa (Rafinesque, 1820), Murray and Leonard, 1962; Valentine
and Stansbery 1971; Johnson 1980; Branson 1982; Oesch 1984; Turgeon
and others 1988; Williams and others 1992; Vidrine 1993; Watters 1995;
Howells and others 1996
Description:
“Shell large, elongated, solid, subrhomboid, scarcely inflated, inequilateral, with a
decided, curved, elevated ridge, which ends well forward on the posterior base, in front of
which for a long distance there is a shallow excavation; beaks low, compressed,
sculptured with strong, irregular, corrugated ridges that turn up behind; surface covered
as far back as the posterior ridge with irregular, different sized pustules, which sometimes
form somewhat chevon-shaped [sic.] figures; behind the ridge the sculpture consists of
strong, irregular, curved, corrugated and often knobbed ridges; epidermis greenish-
brown, or brown, dark green in young shells; left valve with two ragged, triangular
pseudocardinals and two straight laterals; right valve with one large pseudocardinal, a
small one in front of it, and vestigial teeth behind it, with one lateral, which in heavy
shells may be partly double; beak cavities moderately deep, compressed; anterior scars
rough; posterior scars oval; nacre white, rarely purple. In this remarkable species the
male shell is obliquely truncate at the posterior base, behind the posterior ridge and ends
in a somewhat blunt point considerably above the base line. From this point running
towards the beaks there is generally a row of low, broad nodules or knobs that extend
upward in ridges. In the female shell this area is much smoother, and is extended into a
broad, rounded wing” (Simpson 1914, p 318-319).

Table 36. Summary of T. verrucosa shell characters.

Mean H/L Max. Mean W/L
H/L Range Length W/L Range
Location N (%) (%) (mm) (%) (%) Remarks
Arkansas River System
Caney River 18 55.4 50.0-60.5 168 27.6 22.2-33.6 1 of 16 pink nacre
Sand Creek 2 62.0 60.7-63.3 120 31.1 30.0-32.1 -
(Caney R. dr.)
Verdigris River 21 55.8 46.1-65.0 153 29.7 25.0-35.8 3 of 15 pink nacre
Neosho River 13 57.4 47.7-63.2 161 28.4 24.4-33.6 1 of 13 pink nacre
Poteau River 5 53.1 47.3-56.5 134 32.4 28.2-38.0 2 of 15 pink nacre
Illinois River 8 55.2 50.9-59.8 151 30.4 28.7-32.9 all white nacre
Red River System
Washita River 18 56.7 49.1-61.1 159 - 32.1 fossil/subfossil
Blue River 20 53.9 47.3-60.8 146 28.8 23.0-35.4 9 of 19 pink nacre
Muddy Boggy River 7 59.8 50.9-68.0 114 34.5 28.1-39.6 all white nacre
Kiamichi River 28 56.9 50.0-65.3 126 32.9 26.9-46.1 5 of 28 pink nacre
Little River 19 57.3 50.0-61.3 112 31.4 25.9-37.9 5 of 19 pink nacre
Glover River 8 54.6 48.5-60.8 111 32.0 29.1-35.1 1 of 8 pink nacre
Mountain Fork River 13 54.1 46.2-58.3 118 29.7 26.5-33.3 6 of 14 pink nacre

General Distribution:
Mississippi River system and Gulf of Mexico tributaries from Alabama through
Texas.

187