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

KLIMA: ELECTROTAXIS OF TWELVE FISHES
1609
TABLE 4. Average times in seconds to swim one lap (4.5 m) at various voltages and pulse rates for three fishes.
Volts per _ Pulses per sec
l0 cm 5 15 25 35 45 55
Butterfish
l.0 9.711.96$
10(l0)e 7.812.36
10 12.014.58 4.411.20 4.711.02 4.910.90

3.0
16.314.85 (10)
7.313.44 10(10)
4.511.22 11(11)
7.012.46 15(15)
1.7.0.45 8(10;5)°
5.111.35

4.5 9(10) 10(10) 10(10) 10(10) 10(10) 7(10)
7.9+2.09
4(6;6)
Croaker
1.5 34.4111.03 8.9 0 25.0115.37 0 0

3.0 5(10)
19.7+14.59 1(10)
6
813
11 0(11;10)
0 2(10;8) 0(10;10) 0(3;3)

4.5
10(10)
13
1 X3
88 .
.
6(10;6)
0
0(11;11) 0
0(10;10)
.
.
6(12)
0(10;10) 0
0(10;10) 0
0(10;10)
Chub mackerel
1.5 3.611.58 5.7f1.90 8.3f4.47 6.1 f6.83

3
0 6(6) 10(10) 7(10;6) 10(10;1)
. 4.913.50
4(4)
aAveragc and 95°~o confidence interval.
bNumber of fish responding and number tested.
°The second numeral in parentheses is the number in tetanus
The effective pulse rate for coastal pelagics varied
widely for all but four of the ten coastal pelagic
fishes (Table 3). The four had specific repetition rate
requirements of 15 pulses/sec. There was no rela-
tion between the type offish and optimal pulse rate;
however, a low repetition rate is much more effec-
tive for developing the proper electrical field in
terms of power requirements.
Included in Table 3 is a list of current densities.
These were calculated for sea water from resistances
of 1.8 to about 2.6 ohms, depending on salinity
and temperature, low salinity and temperature
giving a greater resistance. Using the calculated
values of resistance, the current was computed (i.e.
E
I = R (Sears and Semansky 1955)) at 26.0-37.5
amp at 15 v/m (i.e. total voltage = 67.5). The cur-
rent densit J = I
y, A , where A is the area, ranged
from 43.3 to 62.5 amp/m2. At 3.0 v/10 cm the
current density was twice as large as at 1.5 v/10 cm.
In terms of the most etiicient power requirements the
lower potential is better than the higher.
Spanish sardine, scaled sardine, and butterfish
were the only species which had two effective
voltages: 1.5 and 3.0 v/10 cm. As expected, the
higher voltage had twice the current density.
Considerable differences were exhibited in the
reaction times to swim one lap and percent in tetanus
at different voltages for both scaled sardine and
Spanish sardine (Fig. 3). Percent of fish in tetanus
was greatest at the highest voltage and decreased
with a decrease in voltage. At the intermediate and
highest voltages, the percent of fish ~in tetanus in-
creased with pulse rate. The shortest times for one
lap were from 15 to 55~ pulses/sec at 1.5 v/l0 cm
for scaled sardine and from l5 to 25 pulses/sec at
3 v/l0 cm for Spanish sardines. The indexes of
optimal response indicate the combinations of
l .5 v/10 cm at 35 and 45 pulses/sec and 3 v/10 cm
at 15 pulses/sec to be the most effective for Spanish
sardine, and 1.5 v/10 cm at 15-55 pulses/sec for
scaled sardine.
The most effective electrical combinations for
round herring (Fig. 4) and silver anchovy (Fib. 2)
were 3 v/10 cm at 25-45 pulses/sec. The greater
potential required by these species is probably due to
sine. At an average size of about 100 mrn rota]
length the voltage drop between head and tail is
less than that for longer fish. All of the other tested