William K. Anderson

William M. Lewis

Crossref

Use of a Sudden Temperature Decrease to Reduce the Excitability of Channel Catfish during Handling

Southern Illinois University Carbondale
OpenSIUC
Publications Fisheries and Illinois Aquaculture Center
10-1974
Use of a Sudden Temperature Decrease to Reduce
the Excitability of Channel Catfish During
Handling
William K. Anderson
Southern Illinois University Carbondale
William M. Lewis
Southern Illinois University Carbondale
Follow this and additional works at: http://opensiuc.lib.siu.edu/fiaq_pubs
© by the American Fisheries Society 1974
Published in The Progressive Fish-Culturist, Vol. 36, Issue 4 (October 1974) at doi: 10.1577/
1548-8659(1974)36[213:UOASTD]2.0.CO;2
This Article is brought to you for free and open access by the Fisheries and Illinois Aquaculture Center at OpenSIUC. It has been accepted for inclusion
in Publications by an authorized administrator of OpenSIUC. For more information, please contact opensiuc@lib.siu.edu.
Recommended Citation
Anderson, William K. and Lewis, William M. "Use of a Sudden Temperature Decrease to Reduce the Excitability of Channel Catfish
During Handling." (Oct 1974).
USE OF A SUDDEN TEMPERATURE DECREASE TO 
REDUCE THE EXCITABILITY OF CHANNEL 
CATFISH DURING HANDLING 
WILLIAM K. ANDERSON and WILLIAM M. LEWIS 
Fisheries Research Laboratory and Department of Zoology 
Southern Illinois University, Carbondale, Illinois 62901 
HARVESTING AND SUBSEQUENTLY HANDLING 
fishes at water temperatures of approximately 
80øF or greater often results in mechanical damage, 
physiological stress, and mortality. Yet the sale of 
channel catfish to be used in pay-fishing, and the sale 
of bait minnows, requires harvesting and handling in 
midsummer. Harry [1] reported using "thermal 
shock" to reduce mortality of golden shiners 
(Notemigonus crysoleucas) when they are har- 
vested and handled at high temperatures. He advo- 
cated moving fish from the warmwater pond directly 
to 60øF water on the harvest truck. However, he 
pointed out that when moving fish from the hauling 
tank to holding tanks with higher temperatures, it is 
necessary to temper the fish at a rate not greater 
than 10øF per hour. 
We have examined the effects on channel catfish 
(Ictalurus punctatus) of the instantaneous temper- 
ature change of 80 ø to 60øF(26.6 ø to 15.5øC), main- 
tained for periods of i to 8 hours, followed by instan- 
taneous return of the fish to 80øF water. The objec- 
tives were to determine if the channel catfish would 
tolerate these instantaneous temperature changes, 
and if this procedure could be used to reduce excita- 
bility, with a resulting reduction of physiological 
stress and mechanical damage. 
NOTE.--This paper is based on a research report submitted by 
William K. Anderson to the Graduate Faculty of Southern Illinois 
University in 1973 in partial fulfillment of the requirements for 
the Master of Science Degree. The study was supported by 
Southern Illinois University. 
Mr. Anderson's present address is Mississippi Game and 
Fish Commission, Division of Fisheries, P.O. Box 451, Jackson, 
Miss. 89205. 
VOL. 36, NO. 4, OCTOBER 1974 
MATERIALS AND METHODS 
Three procedures were used to evaluate the ef- 
fects of sudden temperature change. In the first 
procedure, yearling channel catfish (18.0 to 170 
grams, mean 60.5) were acclimated to aquarium 
conditions at 80øF (_+3ø). The fish were then moved 
by dip nets to adjacent tanks containing 60øF water 
(_+2ø), held there for i to 8 hours, and returned 
without acclimating to 80øF water. To demonstrate 
the effects of handling, fish were also moved from 
80 ø to 80øF water. The effects of the temperature 
change were evaluated by observing for evidence of 
abnormal behavior and mortality for a period of 10 
days after the fish were transferred. 
The second procedure consisted of measuring 
oxygen consumption of fish transferred from 80 ø to 
60øF water, as compared to that of fish transferred 
from 80 ø to 80øF water. Oxygen consumption was 
measured with a constant head respirometer, using 
8 experimental fish and 8 control fish (35.0 grams, 
_+1.5). Oxygen consumption was determined at 
10-minute intervals for 8 hours. The mean values of 
consumption for the two treatments were compared, 
using a modified two-way analysis of variance [2]. 
The third procedure consisted of actual hauling 
trials ranging in length from i to 4 hours. Fish were 
seined from a pond and transported in a fiberglass 
hauling tank mounted on a pickup truck. Water 
temperatures of the ponds from which the fish were 
harvested ranged from 83øto 86øF. By using ice, the 
water temperature of the hauling tank was main- 
tained 20øF below the temperature of the pond from 
which the fish were taken. After being hauled, the 
fish were placed either in aquariums or in clear- 
213 
water ponds free of other fish. Mortality occurring 
during a 10-day period after hauling was recorded. 
RESULTS 
When fish were transferred from 80 ø to 60øF 
water and held from 1 to 8 hours, no mortality at- 
tributable to the transfer occurred during the 10-day 
observation period following (table 1). Both experi- 
mental and control fish fed the day following the 
transfer, with one exception. One lot of experimen-- 
tal fish exposed to 60øF for 6 hours did not feed until 
the second day following transfer back to the warm 
water. The experimental fish exhibited a fairly pre- 
dictable behavior pattern. Following introduction 
into the 60øF water, the fish swam slowly around the 
aquarium for about 5 minutes, then settled to the 
bottom and lay still for 45 to 60 minutes, after which 
they became more active, alternately swimming 
slowly and lying still for the duration of the exposure 
to the 60øF water. Activity tended to increase with 
the length of time the fish were held at 60øF, but 
they were always less active and less excitable than 
the control fish. Less than 5 minutes after they were 
returned to 80øF water, the experimental fish com- 
menced to exhibit behavior identical to that of the 
control fish. 
Table 1.•Mortality of channel catfish exposed to 
the sudden temperature change from 80 ø to 
60øF followed by immediate return to 80øF 
Hours held Number Mortality 
at 60 ø F of fish (numbers) 
1 .................................. 60 0 
2 .................................. 70 0 
4 .................................. 75 0 
6 .................................. 113 1 
8 .................................. 240 2 
8 (control) ......................... 151 i 
Table 2.•ortality of channel catfish exposed to 
sudden temperature decreases from 80 ø to 50 ø F 
or less followed by immediate return to 80 ø F 
Temperature Hours held 
Lowered to at lowered Number Mortality 
(øF) temperature of fish (numbers) 
50 ............ I 52 0 
45 ............ i 52 0 
45 ............ 2 52 0 
40 ............ i 145 40 
Control ....... i 52 0 
water, the fish remained motionless on the bottom 
for 5 to 20 minutes before resuming activity. Of the 
40 fish that died following the 1-hour exposure to 
40øF water, 38 never resumed activity following 
exposure (table 2). They were apparently killed im- 
mediately by the temperature change. One fish died 
5 days after the experiment, and another died 9 days 
afterwards. 
In the hauling experiment, no mortality occurred 
when the fish were subjected to a 20øF change in 
temperature and transported for i to 4 hours (table 
3). 
Table 3.•lortality of channel catfish exposed to 
the sudden temperature decrease of 20 ø F in 
actual hauling trials followed by immediate 
return to the original temperature 
Temperature Hours held Approximate 
change at lowered number Mortality 
(øF) temperature of fish (numbers) 
86-66 ......... 1.00 200 0 
86-66 ......... 3.25 450 0 
83-63 ......... 4.00 240 0 
83-63 ......... 4.00 290 I 
Fish transferred from 80 ø to 50øF or cooler water 
exhibited an initially violent reaction for the first few 
minutes. They convulsed violently and attempted 
to leap out of the water. Some swam upside down 
or on their sides, then sank to the bottom and lay on 
their sides or backs. The majority of the fish lost 
their equilibrium. After extended exposure to the 
low temperature, a few fish regained their equilib- 
rium, but all remained lying on the bottom and ex- 
hibited no activity (table 2). When returned to 80øF 
214 
Oxygen consumption of the control fish was much 
higher than that of the experimental fish im- 
mediately after handling, and remained higher dur- 
ing the following 8-hour period (fig. 1). The differ- 
ence between the two treatments was statistically 
significant at the 0.05 level. After being returned to 
80øF water following an 8-hour exposure to 60øF 
water for the experimental fish and 80øF water for 
the controls, oxygen consumption by the fish was 
highly variable (fig. 2). 
THE PROGRESSIVE FISH-CULTURIST 
38O 
360 !
• 340 ß 
"' 320. 
"' 300 ß 
• 280 ß
Z 
0 260, 
_ 
nP 240 ß 
:• 220. 
• 200 *
O 180 -• 
Z 
uJ 
C0 160, 
1201 
1001 
801 
0 • 
O----4•CONTROL 
T e- ,=EXPERIMENTAL 
% 
,',, 
T 
• T m 
10 70 130 190 250 310 370 430 
TIME IN MINUTES 
Figure 1.--Mean oxygen consumption of eight 
channel catfish transferred from 80 ø to 80øF 
water (control) vs. eight channel catfish trans- 
ferred from 80 ø to 60øF water (experimental). 
300- 
• 280- 
'• 260- 
'•. 240- 
•E 220- 
z 
o 200- 
D. 180- 
• 190- 
• 160- 
U 
Z 140- 
C0 120- 
) 100- 
80- 
0 
ß .... eCONTROL 
e----eEXPERIM ENTAL 
I I I I i : 
10 20 30 40 50 60 
TIME IN MINUTES 
Figure 2.--Mean oxygen consumption of eight 
control and eight experimental channel catfish 
returned to 80øF water following 8-hour expo- 
sures to control (80øF) and experimental (60øF) 
temperatures. 
CONCLUSIONS 
The excitability of yearling channel eatfish can be 
successfully controlled by instantaneous transfer of 
the fish from 80 ø to 60øF water. Following transfer, 
the fish can be held at the lower temperature for at 
least 8 hours and not exhibit noticeable effects when 
they are transferred back to the higher tempera- 
ture. Tempering is not necessary when the fish are 
returned to 80øF water. This technique can be suc- 
cessfully applied to harvesting and handling channel 
catfish when pond water temperature is unfavorably 
high. 
REFERENCES 
1. HARRY, GEORGE V. 
1968. Handling and transporting golden shiner minnows. 
Pages 37-42 in Proceedings of the Commercial Bait 
Fish Conference, Texas A&M University, College Sta- 
tion, Texas. 
2. LINDQUIST, E. F. 
1953. Design and analysis of experiments in psychology 
and education. Riverside Press, Cambridge, Mass. 393 p. 
VOL. 36, NO. 4, OCTOBER 1974 215 


English

Southern Illinois University Carbondale
OpenSIUC
Publications Fisheries and Illinois Aquaculture Center
10-1974
Use of a Sudden Temperature Decrease to Reduce
the Excitability of Channel Catfish During
Handling
William K. Anderson
Southern Illinois University Carbondale
William M. Lewis
Southern Illinois University Carbondale
Follow this and additional works at: http://opensiuc.lib.siu.edu/fiaq_pubs
© by the American Fisheries Society 1974
Published in The Progressive Fish-Culturist, Vol. 36, Issue 4 (October 1974) at doi: 10.1577/
1548-8659(1974)36[213:UOASTD]2.0.CO;2
This Article is brought to you for free and open access by the Fisheries and Illinois Aquaculture Center at OpenSIUC. It has been accepted for inclusion
in Publications by an authorized administrator of OpenSIUC. For more information, please contact opensiuc@lib.siu.edu.
Recommended Citation
Anderson, William K. and Lewis, William M. "Use of a Sudden Temperature Decrease to Reduce the Excitability of Channel Catfish
During Handling." (Oct 1974).
USE OF A SUDDEN TEMPERATURE DECREASE TO 
REDUCE THE EXCITABILITY OF CHANNEL 
CATFISH DURING HANDLING 
WILLIAM K. ANDERSON and WILLIAM M. LEWIS 
Fisheries Research Laboratory and Department of Zoology 
Southern Illinois University, Carbondale, Illinois 62901 
HARVESTING AND SUBSEQUENTLY HANDLING 
fishes at water temperatures of approximately 
80øF or greater often results in mechanical damage, 
physiological stress, and mortality. Yet the sale of 
channel catfish to be used in pay-fishing, and the sale 
of bait minnows, requires harvesting and handling in 
midsummer. Harry [1] reported using "thermal 
shock" to reduce mortality of golden shiners 
(Notemigonus crysoleucas) when they are har- 
vested and handled at high temperatures. He advo- 
cated moving fish from the warmwater pond directly 
to 60øF water on the harvest truck. However, he 
pointed out that when moving fish from the hauling 
tank to holding tanks with higher temperatures, it is 
necessary to temper the fish at a rate not greater 
than 10øF per hour. 
We have examined the effects on channel catfish 
(Ictalurus punctatus) of the instantaneous temper- 
ature change of 80 ø to 60øF(26.6 ø to 15.5øC), main- 
tained for periods of i to 8 hours, followed by instan- 
taneous return of the fish to 80øF water. The objec- 
tives were to determine if the channel catfish would 
tolerate these instantaneous temperature changes, 
and if this procedure could be used to reduce excita- 
bility, with a resulting reduction of physiological 
stress and mechanical damage. 
NOTE.--This paper is based on a research report submitted by 
William K. Anderson to the Graduate Faculty of Southern Illinois 
University in 1973 in partial fulfillment of the requirements for 
the Master of Science Degree. The study was supported by 
Southern Illinois University. 
Mr. Anderson's present address is Mississippi Game and 
Fish Commission, Division of Fisheries, P.O. Box 451, Jackson, 
Miss. 89205. 
VOL. 36, NO. 4, OCTOBER 1974 
MATERIALS AND METHODS 
Three procedures were used to evaluate the ef- 
fects of sudden temperature change. In the first 
procedure, yearling channel catfish (18.0 to 170 
grams, mean 60.5) were acclimated to aquarium 
conditions at 80øF (_+3ø). The fish were then moved 
by dip nets to adjacent tanks containing 60øF water 
(_+2ø), held there for i to 8 hours, and returned 
without acclimating to 80øF water. To demonstrate 
the effects of handling, fish were also moved from 
80 ø to 80øF water. The effects of the temperature 
change were evaluated by observing for evidence of 
abnormal behavior and mortality for a period of 10 
days after the fish were transferred. 
The second procedure consisted of measuring 
oxygen consumption of fish transferred from 80 ø to 
60øF water, as compared to that of fish transferred 
from 80 ø to 80øF water. Oxygen consumption was 
measured with a constant head respirometer, using 
8 experimental fish and 8 control fish (35.0 grams, 
_+1.5). Oxygen consumption was determined at 
10-minute intervals for 8 hours. The mean values of 
consumption for the two treatments were compared, 
using a modified two-way analysis of variance [2]. 
The third procedure consisted of actual hauling 
trials ranging in length from i to 4 hours. Fish were 
seined from a pond and transported in a fiberglass 
hauling tank mounted on a pickup truck. Water 
temperatures of the ponds from which the fish were 
harvested ranged from 83øto 86øF. By using ice, the 
water temperature of the hauling tank was main- 
tained 20øF below the temperature of the pond from 
which the fish were taken. After being hauled, the 
fish were placed either in aquariums or in clear- 
213 
water ponds free of other fish. Mortality occurring 
during a 10-day period after hauling was recorded. 
RESULTS 
When fish were transferred from 80 ø to 60øF 
water and held from 1 to 8 hours, no mortality at- 
tributable to the transfer occurred during the 10-day 
observation period following (table 1). Both experi- 
mental and control fish fed the day following the 
transfer, with one exception. One lot of experimen-- 
tal fish exposed to 60øF for 6 hours did not feed until 
the second day following transfer back to the warm 
water. The experimental fish exhibited a fairly pre- 
dictable behavior pattern. Following introduction 
into the 60øF water, the fish swam slowly around the 
aquarium for about 5 minutes, then settled to the 
bottom and lay still for 45 to 60 minutes, after which 
they became more active, alternately swimming 
slowly and lying still for the duration of the exposure 
to the 60øF water. Activity tended to increase with 
the length of time the fish were held at 60øF, but 
they were always less active and less excitable than 
the control fish. Less than 5 minutes after they were 
returned to 80øF water, the experimental fish com- 
menced to exhibit behavior identical to that of the 
control fish. 
Table 1.•Mortality of channel catfish exposed to 
the sudden temperature change from 80 ø to 
60øF followed by immediate return to 80øF 
Hours held Number Mortality 
at 60 ø F of fish (numbers) 
1 .................................. 60 0 
2 .................................. 70 0 
4 .................................. 75 0 
6 .................................. 113 1 
8 .................................. 240 2 
8 (control) ......................... 151 i 
Table 2.•ortality of channel catfish exposed to 
sudden temperature decreases from 80 ø to 50 ø F 
or less followed by immediate return to 80 ø F 
Temperature Hours held 
Lowered to at lowered Number Mortality 
(øF) temperature of fish (numbers) 
50 ............ I 52 0 
45 ............ i 52 0 
45 ............ 2 52 0 
40 ............ i 145 40 
Control ....... i 52 0 
water, the fish remained motionless on the bottom 
for 5 to 20 minutes before resuming activity. Of the 
40 fish that died following the 1-hour exposure to 
40øF water, 38 never resumed activity following 
exposure (table 2). They were apparently killed im- 
mediately by the temperature change. One fish died 
5 days after the experiment, and another died 9 days 
afterwards. 
In the hauling experiment, no mortality occurred 
when the fish were subjected to a 20øF change in 
temperature and transported for i to 4 hours (table 
3). 
Table 3.•lortality of channel catfish exposed to 
the sudden temperature decrease of 20 ø F in 
actual hauling trials followed by immediate 
return to the original temperature 
Temperature Hours held Approximate 
change at lowered number Mortality 
(øF) temperature of fish (numbers) 
86-66 ......... 1.00 200 0 
86-66 ......... 3.25 450 0 
83-63 ......... 4.00 240 0 
83-63 ......... 4.00 290 I 
Fish transferred from 80 ø to 50øF or cooler water 
exhibited an initially violent reaction for the first few 
minutes. They convulsed violently and attempted 
to leap out of the water. Some swam upside down 
or on their sides, then sank to the bottom and lay on 
their sides or backs. The majority of the fish lost 
their equilibrium. After extended exposure to the 
low temperature, a few fish regained their equilib- 
rium, but all remained lying on the bottom and ex- 
hibited no activity (table 2). When returned to 80øF 
214 
Oxygen consumption of the control fish was much 
higher than that of the experimental fish im- 
mediately after handling, and remained higher dur- 
ing the following 8-hour period (fig. 1). The differ- 
ence between the two treatments was statistically 
significant at the 0.05 level. After being returned to 
80øF water following an 8-hour exposure to 60øF 
water for the experimental fish and 80øF water for 
the controls, oxygen consumption by the fish was 
highly variable (fig. 2). 
THE PROGRESSIVE FISH-CULTURIST 
38O 
360 !
• 340 ß 
"' 320. 
"' 300 ß 
• 280 ß
Z 
0 260, 
_ 
nP 240 ß 
:• 220. 
• 200 *
O 180 -• Z 
uJ 
C0 160, 
1201 
1001 
801 
0 • 
O----4•CONTROL 
T e- ,=EXPERIMENTAL 
% 
,',, 
T 
• T m 
10 70 130 190 250 310 370 430 
TIME IN MINUTES 
Figure 1.--Mean oxygen consumption of eight 
channel catfish transferred from 80 ø to 80øF 
water (control) vs. eight channel catfish trans- 
ferred from 80 ø to 60øF water (experimental). 
300- 
• 280- 
'• 260- 
'•. 240- 
•E 220- 
z 
o 200- 
D. 180- 
• 190- 
• 160- 
U 
Z 140- 
C0 120- 
) 100- 
80- 
0 
ß .... eCONTROL 
e----eEXPERIM ENTAL 
I I I I i : 
10 20 30 40 50 60 
TIME IN MINUTES 
Figure 2.--Mean oxygen consumption of eight 
control and eight experimental channel catfish 
returned to 80øF water following 8-hour expo- 
sures to control (80øF) and experimental (60øF) 
temperatures. 
CONCLUSIONS 
The excitability of yearling channel eatfish can be 
successfully controlled by instantaneous transfer of 
the fish from 80 ø to 60øF water. Following transfer, 
the fish can be held at the lower temperature for at 
least 8 hours and not exhibit noticeable effects when 
they are transferred back to the higher tempera- 
ture. Tempering is not necessary when the fish are 
returned to 80øF water. This technique can be suc- 
cessfully applied to harvesting and handling channel 
catfish when pond water temperature is unfavorably 
high. 
REFERENCES 
1. HARRY, GEORGE V. 
1968. Handling and transporting golden shiner minnows. 
Pages 37-42 in Proceedings of the Commercial Bait 
Fish Conference, Texas A&M University, College Sta- 
tion, Texas. 
2. LINDQUIST, E. F. 
1953. Design and analysis of experiments in psychology 
and education. Riverside Press, Cambridge, Mass. 393 p. 
VOL. 36, NO. 4, OCTOBER 1974 215 


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Use of a Sudden Temperature Decrease to Reduce the Excitability of Channel Catfish during Handling

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