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Top Invasive Concerns: Rusty Crayfish
Top Invasive Concerns: Rusty Crayfish

​​​What are ​​​​​​​​​​rusty crayfish​?

​Rusty crayfish are a la​rger, more aggressive freshwater crayfish, native to the Ohio River Basin. The rusty patches on either side of their body can sometimes identify them. They are believed to have been introduced to Colorado by anglers ​​as bait. These crayfish will eat small fish, aquatic insects, eggs and even aquatic vegetation, damaging underwater habitat that is important for fish spawning, cover and food. They also outcompete and displace native crayfish. 

Where have ​​​​​​​​​​rusty crayfish​ been found?

Rusty crayfish were first detected in Colorado in the Yampa River and Catamount Reservoir in 2009, then again in Sanchez State Wildlife Area in 2010 and in Stagecoach Reservoir State Park in 2011.  Populations have been managed through manual removal of adult rusty crayfish to reduce the reproducing population in the reservoirs and limit impacts to native communities and users. ​​​

2023 Rusty Crayfish Map
*Click on map for larger image

Help prevent the spread of rusty crayfish!

Use only Colorado bait!  Never bring in live aquatic bait from another state.

Crayfish can be taken for personal consumption in Colorado, but care should be taken with their use and disposal. Even though crayfish can be taken live east of the Continental Divide, it is recommended that tails of all crayfish be removed immediately and packed in ice for transport. 

Do not throw unused bait crayfish, or bait of any kind, back in the water alive.

Do not dispose of pets or unwanted aquarium plants or animals in natural systems.  Never dump or release plants or animals in reservoirs, lakes, ponds, rivers, streams or any water body. 

Live transport prohibited​!

The live transportation of all crayfish from waters west of the Continental Divide is prohibited.  All crayfish caught west of the Continental Divide must be immediately killed (by removing the head from the thorax) and taken into possession, or immediately returned to the water from which they were taken. 

At Sanchez Reservoir State Wildlife Area, rusty crayfish have been positively identified.  To prevent their spread within and beyond this area, a CPW order prevents the transport of any live crayfish from Sanchez Reservoir SWA in Costilla County.