• Guilbault, G.G.
  Louisiana State University
  
• Lozes, R.L.
  Louisiana State University
  
• Moore, W.
  Louisiana State University
  
• Kuan, S.S.
  Louisiana State University
  

The increasing occurrence and use of pesticides (organophosphorus, carbamate and chlorinated) has focused great attention on the development of quantitative assays for low concentrations of these pesticides. Guilbault and Kramer, used both lipase and cholinesterase enzymes to determine very low concentrations of certain pesticides. Guilbault, Sadar and JKuan, have isolated new species of cholinesterase from insects and animals have studied their inhibition by various pesticides. Inhibition was predominately by organophosphorus insecticides. Guilbauilt et al, have already reported the inhibition of lipase by chlorinated insecticides such as Aldrin, Lindane, Heptchlor, DDT and a carbamate, Sevin. Guilbault, Sadar and Kuan have found that the enzyme hexokinase is inhibited very selectively by only a few chlorinated pesticides, thus providing a good analytical method for these compounds.

Since it has been reported that various aquatic species respond in different ways to different insecticides or pesticides, we thought it desirable to isolate the purified enzyme from different aquatic species and study their inhibition by pesticides. Three species were chosen for study: trout, crayfish and fiddler crabs.