摘要：A bivalve shell gape monitor, previously used to detect toxic discharges in Europe, was used to measure response of the freshwater mussel Amblema plicata plicata (Say 1817) (Mollusca: Unionidae) to brief changes in water velocity. In the laboratory, overall behavior of eight A. p. plicata was virtually unaffected by exposure once every 2 hr to a 5-min pulse of high-velocity water (45 cm/s) created with a submersible pump. In the east channel of the upper Mississippi River near Prairie du Chen, WI, multiple passes of recreational craft reduced by only a few percent the total time that six A. p. plicata were opened during a 2-hr period. Only six of 42 events, caused by passage of a work boat or a 6.5-m-long skiff, caused a measurable response in mussel shell gape. It was concluded that A. p. plicata was not greatly affected by brief changes in ambient water velocity caused by vessel passage.
