Rusty Crayfish (Orconectes rusticus)
Live crayfish are used classrooms for valuable learning, but please do not release them into wild!
During the school year, within schools in Oregon and the west, the rusty crayfish, native to the Ohio River basin, is a species used for teaching and learning in elementary schools as part of a nationally acclaimed curriculum on “The Structures of Life”. Teachers and students face a dilemma over what to do with rusty crayfish (for that matter any live organism used in a classroom) once the class science project is completed.
Species at a glance
The rusty crayfish is a large crayfish species that has emerged as an invasive threat to aquatic ecosystems in many regions of the country. This opportunistic feeder can exceed 4 inches long, has strong claws, and aggressively displaces native species such as our native American signal crayfish. It is a voracious consumer of aquatic plants, fish eggs, and invertebrates.
Identification
Rusty crayfish are most easily identified by large, rust-colored spots on either side of the carapace (shell). They have large, reddish-brown to grayish-green claws with black bands at the tips. The claws leave an oval gap when closed.
How this Species Spreads
Due to its hardy nature, rather attractive features and relatively large size, the rusty crayfish is often used in aquariums, particularly in classroom settings and sometimes as bait for fishing. Releasing aquarium species into new ecosystems provides another pathway for the rusty crayfish to spread.
Habitat
The rusty crayfish inhabits freshwater lakes, rivers, and streams with substrate of rock, gravel, clay or silt. They are found in deep pools and fast currents. They prefer areas that offer shelter from predators, such as rocks, logs, and debris.
What you can do
If you use or see these crayfish in the classrooms in our waterways, please contact the Extension office or call. If you suspect that you’ve come across a rusty crayfish in our local waters, report the sighting to the Oregon Invasive Species Hotline, 1-866-INVADER and contact the Extension Office.
A color publication titled “You Can Stop the Spread of Aquatic Invasive Species (AIS). 2006. 4pp. ORESU-G-06-003” can be obtained at the OSU Washington County Extension office or from.Oregon Sea Grant at OSU :