7130

• UCREFRP Catalog Number: 7130
• Author: Adams, W. J., D. J. Behmer and W. O. Weingarten
• Title: Recovery of Shocked Common Shiner,
• USFW Year: 1972
• Copyright Material: YES

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SHOltT PAPERS AND NOTES

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20 40 60 80 100 120 140 160 180 200
ENERGY DENSITY (MILLIJOULES/C C.)

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FIGURE 2.-Relation between average recovery time
and energy I density of shocked common shiners. Two
standard deviations of the mean are plotted in each
direction from the mean.

stressed the importance of voltage or voltage
drop in causing responses of fish to electrical
current. Past research has shown that fishes
go through a series of responses as the voltage
is increased, one of these stages being complete
immobilization or galvanonarcosis. The pres-
ent study is concerned with the galvanonarcosis
stage. Our results have shown the importance
of current and time in addition to voltage (i.e.,
energy). However, with time held constant,
it can be shown that energy density is directly
proportional to the square of the voltage. The
energy density passing through a fish could
theoretically be calculated as:
. eXixT
Energy DenSIty = V IfF' h
o ume 0 IS
If the resistance of the fish is considered to be
a constant, R, Ohm's Law gives the current
through a circuit with e voltage as e/R. The
above formula now becomes:
e2 X T
Energy Density = R X (Vol. of Fish)

Thus the energy density through the fish
would be directly proportional to the voltage
squared. In studies where the immediate re-
sponse of the fish is measured (i.e., where time
is. not a factor) the above formula becomes:

555

. e2
Power Density = R X (Vol. of Fish)

The present study suggests that power density
may be a more meaningful measure of the
electrical stimulus than simply voltage or volt-
age drop as other workers have used; and
under laboratory conditions where time can he
measured, energy density may even he more
useful. .

LITERATURE CITED

DENZER, H. W. 1956. Die Elektrofischerei. Handb.
Binnenfisch. Mittlerop, Ergansungsband zu Band
5, Lieferung 3. 233 p.
HALSBAND, E. 1967. Basic principles of electric
fishing, p. 57-64. In R. Vibert (ed.), Fishing
with electricity. Fishing News (Books) Ltd.,
London.
HOLZER, W. 1931. Dber eine absolute Reizspannung
bei Fischen. Pfliigers Arch. ges. Physiol. 229:
153-172. .
LAMARQUE, P. 1967. Electrophysiology of fish sub.
ject to the action of an electric field, p. 65-92.
In R. Vibert (ed.), Fishing with electricity. Fish-
ing News (Books) Ltd., London.
PATTEN, B. G., AND C. C. GILLESPIE. 1966. The
Bureau of Commercial Fisheries Type IV electro-
fishing shocker-its characteristics and operation.
U. S. Fish Wildl. Servo Spec. Sci. Rep. Fish. 529.
/ 15 p.
VWERT, R. 1963. Neurophysiology of electric fish.
ing. Trans. Amer. Fish. Soc. 92: 265-275.

WILLIAM J. ADAMS

DAVID J. BEHMER

WARREN O. WEINGARTEN

Lake Superior State College
Sault Ste. Marie, Michigan 49783

A Simplified Device for Metering
Chemicals in Intermittent-flow
Bioassays

Many types of chemical metering devices
for use in intermittent-flow bioassays or other
tests have been described (Mount and W arner~
1965; Mount and Brungs, 1967; Burke and
Ferguson, 1968). Intermittent-flow systems
have several- advantages over static systems in
bioassays, but experimental failures may re-
sult from the malfunction of moving parts
or fluctuations in flow rates. Complex meter-
ing devices require considerable time for
maintenance of proper concentrations.
Accurate delivery is essential when studying

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