Aquatic Invertebrates - invasive

Red Swamp Crayfish (Procambarus clarkii) on Aug 31, 2011

Submitter has sample

Description of specimen

while fishing the creek i saw what i thought was a native signal crawfish but when i grabbed it it was like nothing ive ever seen and im an AVID crawfisherman i see lots of mudbugs i kept it for identification brought it home and found that it is one of the two invasive spp. in oregon. it will live out its days in my aqaurium or be disposed of.


have there been any other reports? and do they have an impact on the native fresh water mussles which are plentiful in this creek?

Aug. 31, 2011, 2:19 p.m.

Dear Scott,

I commend you for being so observant and noting that you definitely did not find a the native signal crayfish! Yes, cox creek and wavery lake are known to be infested with the invasive red swamp crayfish. Thanks for being responsible and not transporting or releasing it into another un-infested water body. I am not aware of any studies showing specifically how the invasive crayfish would impact native mussles, however they do out compete the native crayfish for food and shelter, and can prey on fish and amphibian egg masses and thus decrease their populations as well.

I have a flyer describing the various non native crayfish in Oregon so you can be aware of them as well. I will email it to you separately. Thanks for doing your part to prevent additional spread of these species.

Tania Siemens
WISE Program Coordinator (Watershed and Invasive Species Education)
Oregon Sea Grant Extension
Oregon State University

Tania Siemens
Sept. 1, 2011, 12:26 a.m.

removed another three today two adults and one juvenile... which means there are many more as i grabbed these by hand in mid day

Sept. 1, 2011, 11:05 a.m.