7123 ‎(3)‎

• UCREFRP Catalog Number: 7123
• Author: Klima, E. F.
• Title: Voltage and pulse rates for inducing electrotaxis in twelve coastal pelagic and bottom fishes
• USFW Year: 1972
• USFW - Doc Type: Journal of the Fisheries Research Board of Canada
• Copyright Material: YES

1608 JOURNAL FISHERIES RESEARCH BOARD OF CANADA, VOL. 29, NO. 11, 1972
In addition to voltage, pulse width affects the responses
of fish (Wary ] 9S6). To determine the range of pulse
widths most desirable for the experiments, a series of
tests were conducted on spot to determine the times to
swim one lap at 1.5 vJ10 cm with 25 and 30 pulses/sec
at pulse widths of 0.7, 1.2, and 2.0 msec (Table 2).
At a pulse rate of 25/sec, times ranged from 3.3 to 4.6
sec. At 35 pulses/sec, however, it took an average of
5.4 sec to swim one lap at a pulse width of 0.7 msec,
and 3.2 sec at a 1.2 msec pulse width. These differences
were tested by analysis of variance, which clearly showed
no difference in response times at 35 pulses/sec (F =
2.2G < F.95 (~.z7) = 3.36). Because of the closeness
in response times at 25 pulses, no analysis of variance
was needed.
TABLE 2. Times (sec) to swim one lap (4.5 m)
at three pulse widths for spot stimulated with
1.5 v/10 cm at two pulse rates.
Pulse rate
Pulse width
(msec) 25 35
The responses of fish subject to pulse widths ranging
from 0.7 to 2.0 msec were similar; hence, the test ani-
mals were subjected to pulse widths within this range.
Effective Combinations
The combinations of electrical parameters which
are considered most desirable for inducing elec-
trotaxis and for leading 12 of the 13 species are sum-
marized in 'Table 3. Little difference existed between
the electrical parameters for coastal pelagic and
bottom fish, except for croakers, as control was not
obtained for this species. However, response times
to swim one and two laps and average distance
covered differed greatly between the two groups as
bottom fish swam at much slower speeds and could
not be led as far as the coastal pelagics.
The optimal electrical parameters were similar for
Longspine porgy and spot; the only difference was
that spot could be effectively controlled at a slightly
wider range in repetition rate. Croaker could not be
eIL'cc[ively controlled (Table 4).
Longspine porgy reaction time curves to swim one
lap were similar in shape but not in amplitude for
1.5, 3.0, and 4.5 v/10 cm (Fig. 2). The similarity
in shape indicates that voltage has little effect. A
decrease in pulse rate increased the time to swim
to the anode. Combinations of high voltage and
high pulse rates were undesirable for inducing
electrotaxis in both Longspine porgy and spot.
0.7 4.6~i.lia•b 5.42.09
1.2 4.6f1.22 3.2f0.88
2.0 3.30.41 4.4f1.74°
BAverage and 95°Jo confidence interval.
bThirty fish tested; 10 in other tests.
°Nine fish responded.
TAIILE 3. Effective combinations of voltage (per 10 cm) and pulse rate (per sec) for
inducing electrotaxis in the species studied and the approximate amperes (per m2).

Species
(v)
Pulses
(Amp) Fish length (mm)
Range Avg.
Coastal pelagics
Scaled sardine 1.5 IS-SS 62.5 100-145 118
3.0 8-28 86.5 100-145 118
Spanish sardine 1.5 35-45 43.3 85-180 130
3.0 15 86.5 85-180 130
Round herring 3.0 2515 86. S 80-150 104
Silver anchovy 3.0 35-45 98.3 85-110 96
Butterfish 1.5 35 41.3 80-100 118
3.0 45 86.5 80-160 118
Chub mackerel 1.5 15 53.8 125-240 180
Bumper 1.5 15 57.0 135-230 173
Rough scad 1. S 15-2S 42.3 120--145 133
Thread herring 1.5 15 62.5 80-185 146
Round scad 1.S 15 43.3 90-170 148
Bottom frsh
Spot 1.5 15-35 43.3 90-250 120
Longspine porgy 1.5 25-35 43.3 100-160 128