Winged Mapleleaf (Quadrula fragosa)
(Federally listed as Endangered)
Description:
This is a medium-sized freshwater mussel that is approximately 4
inches in length with a yellowish-green to light brown color. Its
shell is irregularly circular in shape with a well-developed
“wing” and radiating ridges on its posterior end. The upper
surface of the shell also has two rows of pustules or bumps.
Like all freshwater mussels, it is a filter-feeder that filters
fine organic material, suspended algae and microscopic organisms
out of the flowing water around it.
Habitat: Winged Mapleleaf mussels are found in small rivers and
large streams with at least a moderate rate of flow. Within the
river, these mussels embed themselves in areas of gravel or
course sand substrate in the main channel.
Current and Historic Distribution: The Winged Mapleleaf was
recently discovered in the Little River in southeastern
Oklahoma. It also may occur in the Kiamichi and Boggy river
systems. Historically, the Winged Mapleleaf was found in
tributaries of the Mississippi River in at least ten states, but
known populations currently are limited to small rivers in
Oklahoma, Arkansas, Minnesota and Wisconsin.
Reasons for Decline: The causes for its decline are uncertain
but may be related to past water pollution, pesticide use near
waterways, or habitat loss that affected its fish host species.
It is affected also by reservoir construction which fragments
and isolates populations above and below dams.
County by County List of Endangered and Threatened Species
US Fish and Wildlife Endangered Species Lists