A Survey of the Mussels (Unionacea) of the Illinois River

A Polluted Stream

Abstract

The basic purposes of this investigation were to make a survey of the pearly mussel (Mollusca: Pelecypoda: Unionacea) populations of the entire Illinois River in order to formulate a sound basis for managing the mussel resource of this river, and to determine what species and distributional changes had taken place during the past century.