rusty crayfish
Orconectes rusticus (Girard, 1852)

Identifying crayfish can be difficult. Positive identification requires looking at a number of characteristics and having enough experience to interpret them. Rusty crayfish can generally be identified by their more robust claws and by the dark, rusty spots on each side of their carapace; the spots are located on the carapace as though you picked up the crayfish with paint on your forefinger and thumb, but may not always be present or well developed on rusty crayfish from some waters. (Jeff Gunderson, Minnesota Sea Grant College Program)
Habitat and Habits
Rusty crayfish are native to Ohio, Tennessee, and Cumberland drainages as well as the far western Lake Erie watershed. They are found in streams, lakes, and ponds with varying substrates from silt to rock and plenty of debris for cover. They need permanent water and generally do not burrow to escape dry periods.
Ecological Threat
Rusty crayfish were probably introduced outside of their home range via bait-bucket transfers. The introduction of only one female carrying viable sperm could start a new population. Outside their home range, they are likely to displace native crayfish and reduce aquatic plant abundance and diversity.

Identification, Biology, Control and Management Resources