ON THE REACTION OF MARINE FISHES IN INTERRUPTED A.C OF 50 Hz

Abstract

The reactions of marine fishes i-n interrupted A. C. off
uniform electrical fie]d and constant current dt"nsity have been
studied in order to determine the optimum effective periods of shock
:for narcosis and fixation. Higher effective periods were required
with gradual decrease in potential difference between head and tail,
which in turn depended on the length of fish and its position in
electrical field. The body voltage of fish varied directly with the
length and inversely with the rise of angle between their body
axis and field lines. The fish subjected to higher effective pe:riod took
longer time for recovery from narcosis. The effect of impulse
current was manifested by increased rate of giH movements in
P!atax tefora, Haetodon ollaris, Crysophus burda, Siganus vermiculatus
and Scolopsis leucotaenia, and lowered rate of movements
in others when subjected to different effective periods inespective