Common Name: Pyramid Pigtoe
Scientific Name: Pleurobema rubrum
up to 3 inches
Blue = current range
Hollow circles = former range
Status in Kansas:
North American Status: (From NatureServe)
Historically this species was distributed throughout the Mississippi, Wabash, Tennessee, and Ohio River systems. It appears to never have been common. Today the species is widely but very sporadically distributed and has apparently been extirpated from much of its former range. It was reported from the Mississippi River at Prairie du Chien, Wisconsin, but it has not been recovered there recently. It was known to occur in the Illinois River prior to 1900. It was found in the Tuscarawas River of the Muskingum River in Ohio as late as 1919 but has not been recently collected there. It was in the Ohio River in the vicinity of Clermont County but a survey in 1984 did not recover it. It has been extirpated from the Tennessee River in Alabama, the Wabash and East Fork White rivers in Indiana, the Osage River in Missouri, the Beech Fork Salt and Licking Rivers in Kentucky, and the Stones and Holston Rivers in Tennessee. A few small populations persist in Big Black and Yazoo River drainages in Mississippi. The species is fairly widespread and can be locally common in Arkansas in the Little Missouri, Saline, and Ouachita Rivers. In Louisiana, it has been found in Bayou Bartholomew, the upper Mississippi River, Tensas River, Boeuf River, Ouachita River, and Bayou Dorcheat.
Comments: Shells of the pyramid pigtoe are frequently found in the bank deposits of southeast Kansas rivers. They are similar to the round pigtoe but the umbos are so pronounced and pointed, it is probable they are the pyramid pigtoe. It could be argued these are a variant of the round pigtoe, but it would take soft tissue to perform genetic analysis to verify this fact. Live specimens from Kansas probably no longer exist. This species is still found in Ohio and malacologists (scientists who study mollusks) there identified the relic Kansas shells as the pyramid pigtoe. Therefore, it is included here as an example of a mussel species that no longer exists in Kansas.
Fish Hosts: black crappie