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Figure 11. Nitrate high, low, and mean values at tap, dechlorination exit,
tank, and aquarium #9.
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Nitrite high, low, and mean values at tap, dechlorination exit,
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Figure 14. Individual site locations for measurements of nitrite:
dechlorination exit, tank, and aquarium #9.
tap,
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32
.-
Table 2 . Summary of results for experimental period 1, December 12, 1991 to January 2,
1992 {22 days).
Fish
Hybrid
sunfish
1
2
3
4
5
6
Average
Bluegill
7
8
9
10
11
12
Average
Length (mm)
12.12 1.2* Gain
117
116
119
118
109
115
Weight (g)
12.12
1.2
Gain
Food
Conversion
Consumed (g) Efficiency (%)
118
119
120
120
110
118
1
3
1
2
1
3
1.8
20.86
20.75
20.54
21.47
16.40
21.22
25.69
25.64
26.29
24.60
18.80
25.07
4.83
4.89
5.75
3.13
2.40
3.85
4.1
83.80
75.54
81. 17
54.63
59.65
76.49
5.8
6.5
7.1
5.7
4.0
5.0
5.7
112
119
104
107
115
120
110
118
127** 134
126
131
7
3
5
8
7
5
5.8
17.45
16.93
19.80
18.21
28.13
25.00
26.60
9.15
19.37
2.44
27.85
8.05
26.13
7.92
39.49 11.36
36.46 11.46
8.4
146.70
70.74
114.72
121.80
157.20
192.96
6.2
3.4
7.0
6.5
7.2
5.9
6.0
* Fish were measured and weighed the morning of January 3, 1992.
** Measured to tip of upper caudal fin lobe.
-
33
Table 3. Summary of results for experimental period 2, January 3 to January 22, 1992
(20 days).
Fish
Hybrid
sunfish
1
2
3
4
5
6
Average
Bluegill
7
8
9
10
11
12
Average
1.3
Length (mm)
1.22* Gain
118
119
120
120
110
118
1.3
Weight (9)
1.22
Gain
Food
Conversion
Consumed (g) Efficiency (%)
122
126
127
121
114
123
4
7
7
1
4
5
4.7
25.69
25.64
26.29
24.60
18.80
25.07
28.95
30.86
31.05
28.68
20.80
29.97
3.26
5.22
4.76
4.08
2.00
4.90
4.0
94.47
89.20
93.05
83.68
85.75
98.29
3.5
5.9
5.1
4.9
2.3
5.0
4.5
119
127
107
111
120
127
118
126
140
134**
131
139
8
4
7
8
6
8
6.8
26.60
19.37
27.85
26.13
39.49
36.46
34.72
22.26
35.97
33.99
47.14
45.55
8.12
2.89
8.12
7.86
7.65
9.09
7.3
162.10
98.75
164.09
131.60
176.30
217.33
5.0
2.9
4.9
6.0
4.3
4.2
4.6
* Fish were measured and weighed the morning of January 23, 1992
** Measured to tip of upper caudal fin lobe.
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FOOD CONSUMED (9) FOR HYBRID SUNFISH
280
260
o
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220
200
180
160
140
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60
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NUMBER
5
6
Figure 15. Total food consumed by hybrid sunfish for periods 1, 2, and 3,
by individual fish.
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WEIGHT GAIN PER DAY FOR HYBRID SUNFISH FOR PERIOD 1
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FISH
NUMBER
WEIGHT GAIN PER DAY FOR HYBRID SUNFISH FOR PERIOD 2
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NUMBER
WEIGHT GAIN PER DAY FOR HYBRID SUNFISH FOR PERIOD 3
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5
6
AVE
WEIGHT INCREASE (9) FOR BLUEGILL
16
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14
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11
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NUMBER
Figure 21. Total weight gain by bluegill for periods 1, 2, and 3,
by individual fish.
A
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NUMBER
-
44
mm; and in period 3, 44 mm. Average per day by period was 0.26 mm in
period 1; 0.34 mm in period 2; and 0.33 mm in period 3. Results for total
length increase and average length increase per day for individual fish
again revealed wide variability for both hybrid sunfish (Figure 23 and 24)
and bluegill (Figures 25 and 26).
Convers ion efficiency for hybrid sunfish had average values of 5.7%,
4.5 %, and 3.8% in periods 1, 2, and 3 respectively. Bluegill conversion
was similar to hybrid sunfish with average values of 6.0%, 4.6%, and 4.6%
for periods 1, 2, and 3 respectively.
Conversion for individual fish
revealed a general decrease through the experiment for hybrid sunfish
(Figure 27), and wide variability for bluegill (Figure 28).
-.
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LENGTH INCREASE (mm) FOR HYBRID SUNFISH
13
o
12 -I
11
Period
f2) Period
III Period
1
1
2
3
10
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4
3
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FISH
4
5
6
NUMBER
Figure 23. Total length increase by hybrid sunfish for periods 1, 2, and 3,
by individual fish.
A
U1
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46
LENGTH INCREASE PER DAY FOR HYBRID SUNFISH FOR PERIOD 1
0.6
eE 0.5
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NUMBER
LENGTH INCREASE PER DAY FOR HYBRID SUNFISH FOR PERIOD 2
0.6 -
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NUMBER
LENGTH IINCREASE PER DAY FOR HYBRID SUNFISH FOR PERIOD 3
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6
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BLUEGILL
13
o
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Period 2
Period 3
10
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FISH
10
11
12
NUMBER
Figure 25. Total length increase by bluegill for periods 1, 2, and 3, by
individual fish.
A
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LENGTH INCREASE PER DAY FOR BLUEGILL FOR PERIOD 1
0.6
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8
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NUMBER
LENGTH INCREASE PER DAY FOR BLUEGILL FOR PERIOD 2
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NUMBER
12
AVE
LENGTH INCREASE PER DAY FOR BLUEGILL FOR PERIOD 3
-
0.6
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FOOD CONVERSION EFFICIENCY (%) FOR HYBRID SUNFISH
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4
NUMBER
5
6
Figure 27. Food conversion efficiency by hybrid sunfish for periods 1, 2,
and 3, by individual fish.
A
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FOOD CONVERSION EFFICIENCY (%) FOR BLUEGILL
8
!
r--
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Period 1
Period 2
Period 3
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10
11
12
NUMBER
Figure 28. Food conversion efficiency by bluegill for periods 1, 2, and 3,
by individual fish.
Ul
o
51
-
DISCUSSION
Examination of the data collected on a average per day basis
revealed a significant difference Ct.-test; P<O.OS) in the amount of food
consumed for all periods comparing hybrid sunfish and bluegill (Figure 29).
Statistical analysis of food consumed was in agreement with that
expected by observation. Bluegill tended to consume a greater amount of
food on a consistent basis.
Evaluation of the weight increase by hybrid sunfish and bluegill did
not reveal si~Jnificant differences upon statistical analysis (t.-test;
P>O.OS) (Figure 30).
Similarly, examination of average length increase
per day did not reveal significant differences (t.-test; P>O.OS), with the
exception of period 1 (Figure 31). The significant difference observed in
period 1 is thought to be due to feeding behaviors of the hybrid sunfish
throughout that period.
During this time, fish were not feeding regularly,
possibly due to poor acclimation to the isolated conditions of the
experiment.
Finally, as would be expected for closely related fishes,
there was no significant difference observed in the food conversion
efficiency comparing hybrid sunfish and bluegill (t.-test; P>O.OS) (Figure
32).
Although statistical analysis revealed no significant differences
52
AVERA.GE FOOD CONSUMED PER DAY
10
9
8
";.7
....,
)-
c 6
~
0
.....
0
0
0
LI.
5
4
3
~
!
2
O+---~~--~--~--~I--~--~I--~--~I--~--~I--~
BG 1
HY 1
PERIOD 1
BG 2
HY 2
PERIOD 2
BG 3
HY 3
PERIOD 3
Figure 29. Average food consumed per day comparing hybrid sunfish and
bluegill with 95% confidence intervals.
53
..-
AVERAGE WEIGHT GAIN PER DAY
0.6
0.5
-~
) i-
c
004
Q
....
~
:c
0.3
~
"")I
0.2
0.1
I
BG 1
HY 1
PERIOD 1
I
BG 2
HY 2
PERIOD 2
BG 3
HY 3
PERIOD 3
Figure 30. Average weight gain per day comparing hybrid sunfish and
bluegill with 95% confidence intervals.
54
AVERAGE LENGTH INCREASE PER DAY
0.5
_ 0.4
e
....,e
)-
~ 0.3
....
:c
I-
o
zLI.I 0.2
...I
0.1
I
O.O+---'-~~-'--~--IIr-~---r--~--'I--~--Ir~
BG 1
HY 1
BG 2
HY 2
BG 3
HY 3
PERIOD 1
PERIOD 2
PERIOD 3
Figure 31. Average length increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals .
-
.
55
-FOOD CONVERSION EFFICIENCY
-
8
!
7
)-
u
z
k!:! 6
....~
tl
5
z
9(/) 4
l:1li:
WoI
~ 3
o
u
8
....o
2
O+---r-~~-'--~--'Ir-~---rl--~--'---~~I~~
BG 1
HY 1
PERIOD 1
BG 2
HY 2
PERIOD 2
BG 3
HY 3
PERIOD 3
Figure 32. Food conversion efficiency comparing hybrid sunfish and
bluegill with 95% confidence intervals.
-
56
between hybrid sunfish and bluegill for growth in weight or length, there
was a biological trend indicating that growth of the bluegill was greater
than the hybrid sunfish within the experimental conditions.
Although
averages were not significant, the weight gain and length increase of
bluegill were consistently higher than the hybrid sunfish in all sample
periods.
Lack of statistical agreement was due to variation of individual
fish in both experimental groups, as well as the small sample size.
Observational data revealed some information important to
interpretation of the results found.
Bluegill acclimated more quickly to
the isolated experimental conditions than did the hybrid sunfish.
This was
observed primarily in feeding, with a significantly greater amount of food
consumed by the bluegill.
Additionally, the bluegill appeared to be more
"comfortable" in the isolated conditions.
They were anticipatory of
feeding and swam to the surface when aquaria were opened, feeding
aggressively in the presence of the person introducing food.
In contrast,
the hybrid sunfish did not appear to acclimate as quickly or as
"comfortably" to the experimental conditions. They consumed a
significantly lesser amount of food than did the bluegill, and exhibited
little or no response to feeding stimuli.
Hybrid sunfish were not
anticipatory nor exceedingly active during feeding, often remaining in a
57
corner near the bottom of the aquarium, or near the airstone.
The feeding response of the hybrid sunfish appeared to be due in
part to the lack of social interaction resulting from the experimental
conditions.
Observation of both hybrid sunfish and bluegill outside of the
experimental nroup in the main raceway tank revealed aggressive,
competitive feeding by all members. This was in contrast to the delayed
feeding displayed by one or two bluegill, on occasion, and all hybrid
sunfish in the isolated experimental conditions.
A follow-up experiment in which all 1 2 of the experimental fish
were released into the main raceway tank began on February 28, 1992, and
ran for a period of 20 days until March 1 9.
All fish were weighed and
measured at the beginning and end of the period in the manner previously
discussed.
Results of this experiment revealed the hybrid sunfish under
these conditions demonstrated an appreciable growth increase over that
of the bluegill (Table 5). The average length increase of the hybrid sunfish
was 7.5 mm as compared to 3.3 mm for the bluegill.
Statistical analysis
of average length increase per day, however, was not significant (i-test;
P>O.Os) again, due to small sample size and individual variation (Figure
33). Comparison of the average weight increase revealed 10.64 g for the
."-
hybrid sunfish and 0.14 g for the bluegill. Analysis of weight gain per day
58
Table 5. Data for follow up experimental period, February 28 to March 19, 1992.
Species
.-
Clip
2/28
Length
3/19
Chg.
2/28
Weight
3/19
Chg.
Hybrid
1B
2B
3B
4B
5B
6B
anal clip
upper caudal
left pectoral
right pectoral
lower caudal
no clip
131
132
134
132
121
129
137
146
143
138
121
138
7
14
9
6
0
9
Ave. 7.5
33.63
38.23
35.55
33.52
22.92
35.04
46.31
54.13
46.01
45.66
23.40
47.19
Ave.
Bluegill
7B
8B
9B
lOB
11B
12B
anal clip
upper caudal
left pectoral
right pectoral
lower caudal
no clip
137
116
141
136
149
147
139
118
145
141
152
151
2
2
4
5
3
4
Ave. 3.3
42.64
23.52
47.40
43.55
55.16
53.42
40.80
-1.84
24.44
0.92
48.21
0.81
43.44
-0.11
57.37
2.21
52.28
-1.14
Ave. 0.14
12.68
15.90
10.46
12.14
0.48
12.15
10.64
59
--
AVERAGE LENGTH INCREASE PER DAY
0.7
-
0.6
e
!
0.5
)-
-<
C
0.4
...::c
0.3
.....
IC:I
z
....
....
0.2
0.1
I
0.0
I
BG
HY
Figure 33. Average length increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals, for experimental period
February 28 to March 19, 1992.
60
--
did reveal a siignificant difference (t.-test; P<O.OS) between hybrid sunfish
and bluegill (Figure 34).
Interaction was noted between fish in the
raceway tank, and no "fright response" was observed for either species. In
fact, all fish fed aggressively and competitively.
These observations
suggest that social stimuli plays an important role in the behavior and
feeding of these fish, particularly the hybrid sunfish.
-
61
-"
AVERAGE WEIGHT GAIN PER DAY
0.8
ICI'I
......
)-
-C
0.7
0.6
0.5
Ci
..... 0.4
~
::c
S2 0.3
L&.I
)I
0.2
0.1
0.0
-0.1
I
BG
HY
Figure 34. Average weight increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals, for experimental
period February 28 to March 19, 1992 .
.
-
62
.-.
CONCLUSIONS
Aquaculture experiments were initiated at Ball State University in the
northeast section of the Ball State Greenhouse. Beginning on December
12, 1991, three sequential 22, 20, and 22 day periods were used to
evaluate differences in food consumption, growth, and food conversion
efficiencies between bluegill and Fl hybrid sunfish.
Evaluation of the
results obtained during the 64 day total period allows the following major
conclusions:
1.
Water quality was maintained at acceptable levels throughout the
64 day total period at all sample locations in the experimental
aquaculture system.
2.
There were no statistical differerences in the average growth
rates in weight or in length comparing bluegill and hybrid sunfish
in isolated aquaria, although bluegill did consume significantly
more food than hybrid sunfish.
3.
Variation, as weight gain and length increase, was high between
individuals for bluegill and hybrid sunfish.
4.
Social interactions appeared to have some importance in the
feeding by the fish, particularly the hybrid sunfish.
63
LITERATURE CITED
APHA (American Public Health Association), American Water Works
Associati,on, and Water Pollution Control Federation. 1971.
Standard Methods for the Examination of Water and Wastewater.
APHA, Washington D.C.
Bennett, G. W. 1971. Management of Lakes and Ponds. Van Nostrand
Reinhold Company. New York.
Broussard, M. C. 1991. Aquaculture: Opportunities for the Nineties
Salmonid. 15: 3: 7-14.
Brunson R. W., and H. R. Robinette. 1986. Evaluation of Male Blugill X
Female Green Sunfish Hybrids for Stocking Mississippi Farm Ponds.
North American Journal of Fisheries Management. 6: 156-167.
Carlander, K. D. 1977. Handbook of Freshwater Fishery Biology volume :2. Iowa state University Press. Ames, Iowa.
Childers, W. F. 1967. Hybridization of Four Species of Sunfishes
(Centrarchidae). Illinois Natural History Survey Bulletin. Vol. 29,
Art. 3, pp.1 59-214.
Dalrymple, B. 1986. They're Making Tomorrow's Fish Today. Field and
Stream. 90 (9): 54-94.
Greenberg, B. 1947. Some Relations Between Terrirory, Social
Hierarchy, and Leadership in the Green Sunfish. Physiological
Zoology. 20: 267-294.
Hubbs, C. L. '1955. Hybridization Between Fish Species in Nature.
Systematic Zoology, 4: 1-20.
,..-
Kaufman, D. G. 1973. Selected Experiments of Growth and Food
Conversion Efficiency of Bluegill, Lepomis macrochirus. Ed.D.
Thesis. Ball State University. 49 pgs.
64
Lewis, W. M., and R. Heidinger. 1971. Supplimental Feeding of Hybrid
Sunfish Populations. Transactions of the American Fisheries
Society. 100: 619-623.
Rawson, D. S. 1944. The calculation of oxygen saturation values and their
correction for altitude. Limnology Society of America - Special
Publications. 15: 4.
Werner, E., and D. Hall. 1976. Niche Shifts in Sunfishes:
Experimental Evidence and Significance. Science. 191: 404406 .
. 1977. Competition and Habitat Shift in Two Sunfishes
(Centrarchidae). Ecology. 58: 869-876.
__ . 1979. Foraging Efficiency and Habitat Switching in Competing
Sunfishes. Ecology. 60: 256-264.