Avoidance of Pesticides by Untrained Sheepshead Minnows

The capacity of sheepshead minnows, Cyprinodon variegatus, to avoid six pesticides (DDT, endrin, malathion, Dursban®, Sevin®, and 2,4-D) was investigated. Test fish avoided water containing DDT, endrin, Dursban, and 2,4-D. The fish did not avoid the test concentrations of malathion or Sevin. When fish were exposed simultaneously to two different concentrations of the four pesticides that were avoided, they avoided the highest concentration of 2,4-D but preferred the higher concentration of DDT. Fish did not discriminate between other concentrations of 2,4-D or between different concentrations of endrin or Dursban.