Page 153 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Quadrula quadrula (Rafinesque, 1820), Isely 1925; Valentine and Stansbery
1971; Branson 1982
Quadrula forsheyi (Lea, 1859), Isely 1925
Quadrula fragosa (Conrad, 1836),Isely 1925
Quadrula lachrymosa (Lea, 1828), Isely 1925
Quadrula apiculata (Say, 1829), Simpson 1914; Johnson 1980; Turgeon and
others 1988; Williams and others 1992; Vidrine 1993; Howells and others
1996
Description:
“Shell subrhomboid, rather short, slightly inequilateral, subsolid to solid; beaks
high, moderately full; posterior ridge well developed, narrowly rounded, angled or
showing a tendency to be double, ending in a point or feeble biangulation at the base of
the shell; in front of and behind it there are radial depressions; anterior end rounded,
sometimes obliquely truncated above; basal line sinused in front of the posterior ridge;
outline of dorsal slope raised to an angle behind the ligament, squarely or obliquely
truncate below; surface covered with fine, close pustules, which are often laid down in
zigzag patterns; epidermis greenish in young shells, ashy-brown in old ones, dull;
pseudocardinals radial, somewhat split; lateral of right valve partly double; beak cavities
moderately deep; anterior scars well impressed; nacre white, iridescent behind” (Simpson
1914, p 846).

Table 28. Summary of Q. apiculata shell characters.

Mean Maximum
H/L H/L Range Length Mean W/L W/L Range
Location N (%) (%) (mm) (%) (%)
Lower Red River System
Little River System (Little, 11 77.3 68.4-85.0 100 47.1 42.1-51.2
Mt. Fk. and Glover Rivers)
Kiamichi River 26 79.0 73.3-87.9 96 50.4 41.2-57.3
Gates Creek 4 74.6 72.8-76.3 81 47.3 43.2-51.3
Muddy Boggy River 15 81.5 76.5-85.3 86 50.9 38.0-58.7
Atoka Reservoir (Muddy 12 82.6 76.0-87.7 83 53.4 51.8-55.4
Boggy drainage)
Blue River 12 78.4 72.7-83.3 96 50.5 45.2-55.6
Upper Red River System
Lake Texoma 50 76.9 66.7-83.9 73 47.7 41.7-54.9
Washita River 58 75.0 68.0-82.1 120 40.9 36.7-47.5
Caddo Creek (Carter Co., 5 76.3 73.6-79.2 87 - 40.2
Washita River drainage)
Wildhorse Creek (Garvin Co., 8 76.8 73.1-80.3 86 40.7 38.2-43.2
Washita River drainage)
Rush Creek (Garvin Co., 12 74.3 70.0-80.3 92 - -
Washita River drainage)
Bitter Creek (Grady Co., 11 73.1 68.2-77.1 101 34.7 30.3-38.5
Washita River drainage)
Fort Cobb Reservoir (Caddo 4 75.6 71.6-79.4 102 44.8 42.2-47.1
Co.,Washita River drainage)
Hog Creek (Caddo Co., 5 71.1 63.6-76.3 60 - -
Washita River drainage)

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