摘要：Golden crayfish (Orconectes luteus) specimens were collected in the Mississippi River at Grand Tower, Jackson County, Illinois in September and October 1999. This locality is the most eastern on record for the species and the most southern in Illinois. The high stream order habitat from which these crayfish were collected is generally not consistent habitat compared with preferred smaller order stream habitats used in other parts of the species' range. Previous collections of O. placidus from the Mississippi River may in fact be O. luteus.
