Photo by Bob Gress
used by permission
up to 3 inches
Blue = current range
Hollow circles = former range
- Status in Kansas:
- North American Status:
This species is found
throughout most of Mississippi River drainage from Pennsylvania and New York to Minnesota
and Kansas, south to Missouri, Arkansas, and Louisiana. Also in St. Lawrence River basin
from Lake Ontario to Quebec. Although it has a very wide range and is considered stable
throughout portions of its range, it is likely extirpated from Alabama, New York,
Pennsylvania, Ohio, West Virginia, Nebraska, Kansas, the Tennessee River, and the Detroit
River between Lake St. Clair and Lake Erie, Michigan/Ontario (the latter due to zebra
mussel invasion). In Canada, it only occurs in a small number of rivers in eastern Ontario
and southern Quebec.
Based on the discovery of relic shells found in the Kansas, Ninnescah and Smoky Hill
rivers, we know the hickorynut once occurred here. Thus, it is now considered extirpated.
Outside Kansas, this species is found in medium to large rivers in sand and gravel
substrates. It has a thick, rounded shell with inflated umbos. External color is tan to
brown with faint dark rays extending from the umbo that fade out half-way down the shell.
It could be confused with the round pigtoe or the pimpleback. There is only one known fish
host, which may be an important reason why it disappeared from Kansas.
- Fish Hosts:
Text: Ed Miller, Karen Couch and Jim Mason
Range Maps & Web Design: Jim Mason