Fishes of the Mississippi River.

This chapter provides a listing of fishes known to be present in
the Mississippi River from the headwaters at Lake Itasca, Minnesota to the Gulf
of Mexico terminus. A total of 188 species are presently known from the Mississippi
River, including 3 diadromous species and 17 nonnative species that have
established self-sustaining populations in one or more reaches of the Mississippi
River. Species are classified into three relative abundance categories and noted
as residents, peripherals, introduced (established nonnatives), or strays (introduced
but not established). The diversity of fishes varies longitudinally with 78
species in the reach from the headwaters to St. Anthony Falls; 113 and 105 species
in the upper (Upper St. Anthony Lock and Dam to Pools 13) and lower (Pools
14–26) impounded reaches, respectively; and 121 and 136 species in the upper
(Missouri River confluence to Ohio River confluence) and lower (Ohio River to
the Gulf of Mexico outlet) free-flowing reaches, respectively. Although the composition
of the Mississippi River fish fauna has changed little despite more than
80 years of habitat alteration, the extirpation of five species in individual reaches
of the river may be a forewarning of a system losing resiliency and indicate the
need for habitat conservation and rehabilitation to conserve the biodiversity of
North America’s largest river.