EFFECT OF CHLORPYRIFOS ON ACETYLCHOLINESTERASE
ACTIVITIES OF THE UNIONID MUSSEL AMBLEMA PLICATA

W. J. Doran1, Mark B. Sandheinrich1, Ronald G. Rada1, W. Greg Cope2, Diane L.
Waller3, Scott T. Cooper1. 1River Studies Center, University of Wisconsin--La
Crosse, La Crosse, WI, 54601. 2Department of Toxicology, North Carolina State
University, Raleigh, NC 27695-7633. 3Upper Mississippi Science Center, La
Crosse, WI, 54602.

Populations of freshwater mussels in North America have declined greatly over
the past 30 years.  Studies have demonstrated that effects of pesticides on
freshwater mussels may be significant, especially in highly agricultural areas. 
Depletion of mussel populations in the Upper Mississippi River (UMR), for
example, may have been partly caused by extensive use of organophosphorus
compounds(OPs), such as chlorpyrifos.  However, relatively little is known about
sublethal effects of chlorpyrifos to native unionid mussels in the UMR.  The
effects of chlorpyrifos on the acetylcholinesterase activities of Amblema plicata
will be determined.  A. plicata will be exposed in duplicate to a control and five
concentrations of chlorpyrifos in flow-through aquaria with sand substrate at15 C. 
After 12, 24, and 96 h of exposure, the anterior adductor muscles of four
randomly chosen mussels from each exposure chamber will be analyzed for
acetylcholinesterase activity, a bioindicator of exposure to OPs.  After 24 h of
exposure, six randomly chosen mussels will be removed, marked, and transferred
to a flow-through tank containing clean water and sand.  After 7 and 21 d of
exposure to clean water, the anterior adductor muscles of two organisms from
each treatment will be analyzed for acetylcholinesterase recovery.

Keywords: aceytlcholinesterase, chlorpyrifos, unionid, mussel, organophosphate


Wendi J. Doran
Dept. of Biology/Microbiology
River Studies Center
University of Wisconsin-La Crosse
La Crosse, WI  54601
F: (608) 785-6939T: (608) 785-6991
E: doran_wj@students.uwlax.edu

Poster presentation
No, not willing to convert to platform

Student author