Rhythmical Impedance Changes in Salmon Eggs

Abstract

THE protoplasmic membranes of fertilized and unfertilized trout eggs undergo periodic structural changes after being in tap-water for about seven hours. These changes are associated with variations in electrical impedance¹. The frequency of the impedance change is approximately 1/1.5 min., and the effect can be abolished reversibly by phenyl urethane². Through the kindness of Prof. J. H. Orton, of the University of Liverpool, and Mr. G. M. King, of the Dee Fishery Board, fertilized and unfertilized salmon eggs have been examined in the same way as trout eggs, in an alternating current-bridge of high sensitivity, with a visual detector. Salmon eggs undergo periodic impedance changes (Fig. 1), which are remarkably similar to those previously observed in trout eggs. Their frequency at 16.5° C. is approximately 1/3 min.