Dr. Tim Knight

Procambarus clarkii as a Potential Toxicity Test Species

The goal of this research was to gage the possibility of using the red swamp crayfish, Procambarus clarkii, as a toxicity test species.  The research had three objective’s in determining the potential for use as a supplemental tests to those already in use to protect the nation’s surface waters.  First, can a culture procedure be developed for crayfish that provides for adequate numbers of test organisms that are “healthy”?  Second, can a test method be developed that would be amenable to use by the EPA?  Finally, can acetylcholinesterase activity be used as an indicator of exposure?   Our results indicate that P. clarkii is difficult to maintain in the lab.  This difficulty is magnified due to the crayfish being a seasonal organism, i.e. organisms for testing cannot be purchased year-round.  Acteylcholinesterase has potential for use in toxicity testing, however our results were highly variable indicating that more testing would be required to draw valid conclusions with this species.  Additionally, much more work would be required before this test could be used a supplemental test by EPA.