uptake of the molluscicide, 4' chloronicotinanilide into Biomphalaria glabrata (Say) in a flowing water system

A system is described for the exposure of freshwater snails to pesticides in flowing water. The method allows groups of seven snails to be confined in about 20 ml of water under constant conditions of pesticide concentration, oxygen tension and temperature for up to 5 days. The uptake rate of 4′‐chloronicotinanilide into the planorbid snail, Biomphalaria glabrata (Say), has been measured using this method with liquid scintillation counting techniques. The necessity for an acclimatisation period prior to exposure and the possible influence of activity on uptake is demonstrated. The advantages of the flowing system over exposure in static solutions are discussed and the use of the apparatus in deciding whether relative uptake rates can account for interspecific differences in susceptibility or contribute to the improvement of molluscicide specificity, is indicated.