Distribution: Southern portion of the Mississippi Interior, eastern and western Gulf drainages. In Oklahoma, found primarily in the Red River and its tributaries. Also known from some reservoirs. Some occurrences or Q. apiculata may have been misidentified as Quadrula quadrula.

Life History and Ecology: Primarily a big river species inhabiting unimpounded rivers, but also occurs in some lakes and reservoirs. Short-term brooder and catfishes and centrarchids are the likely host. Equilibrium life history strategy.

Special Status: none

Shell 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; Mather, 2007).