Ouachita Rock Pocketbook (Arkansia wheeleri)
(Federally listed as Endangered)
Description:
This is a medium-sized freshwater mussel with a dark brown to
nearly black, and slightly oval-shaped shell. It is a
filter-feeder that filters particles of decaying vegetation and
microscopic animals and algae from the water that flows around
it.
Habitat: The Ouachita Rock Pocketbook embeds itself in coarse
sediment and gravel at the bottom of the river channel in the
Kiamichi and Little rivers in southeastern Oklahoma.
Current and Historic Distribution: The Ouachita Rock Pocketbook
is a very rare mussel and makes up a fraction of one percent of
the mussel community of the rivers in which it occurs.
Currently, the last remaining populations exist in the Kiamichi
River in Oklahoma, the Little River in southeastern Oklahoma and
southwestern Arkansas, and the Ouachita River in Arkansas.
Historically, they were more widespread in these three rivers
and occurred in other river systems in the Red River drainage of
Arkansas.
Reasons for Decline: The reasons for their decline are uncertain
but may be related to past water pollution or increased sediment
deposition in their habitat. Currently, they are threatened by
existing and proposed new man-made reservoirs because these
alter the season flow patterns of rivers and isolate mussel
populations above and below dams. There are thought to be fewer
than 1,500 adult Ouachita Rock Pocketbooks still in existence.
County by County List of Endangered and Threatened Species
US Fish and Wildlife Endangered Species Lists