DYNAMICS OF PERMEATION OF NEMATODES BY WATER NEMATOCIDES AND OTHER SUBSTANCES

The kinetics of the permeation of five species of nematodes by a variety of substances has been studied. The results demonstrate that these animals are in a dynamic equilibrium with their aqueous environment and the substances in it. A general mathematical formulation for the permeation process has been established that allows for the calculation of equilibrium constants and the specific rates of entrance and exit of substances into and from nematodes. Whereas water, ethylene dibromide, and 1,2-dibromo-3-chloropropane are readily taken up and released by the nemas, glucose, sodium acetate, and glycine are not. This selectivity is lost when the animals are killed. Mixed experiments prove that ethylene dibromide does not alter the permeation characteristics of the nemas. The significance of these results in relation to the mode of action of nematocides and the general biology of the nematodes is discussed. © 1968.