8097

• UCREFRP Catalog Number: 8097
• Author: American Fisheries Society.
• Title: Proceedings of the 18th Annual Meeting, Colorado - Wyoming Chapter, American Fisheries Society.
• USFW Year: 1983.
• USFW - Doc Type: March 2-3, 1983.
• Copyright Material: NO

survival. The results indicate little advantage was gained by feeding with
automatic feeders with surface delivery when compared to the hand-fed fish
groups. Contrarily, lot one which was hand fed a dry diet, had a greater
weight gain than either lots three or four. Hand-fed lots one and two also
had higher survival rates. Lot three had the lowest survival rate. Lot
three appeared to suffer the highest weighing losses but not all the mor-
talities could be attributed to that factor.

Table 3. Growth results, end of experiment (98 days).

Lot

Manner fed

Diet

Wt gain In./day % Survival
(lbs) increase
7.69 .0141 91.6
6.76 .0137 91.2
7.34 .0147 85.6
7.59 .0156 90.5
9.11 .0164 92.2
8.48 .0163 93.4

1 Hand Dry
2 Hand BioDiet
3 Auto-surface Dry
4 Auto-surface BioDiet
5 Auto-submerged Dry
6 Auto-submerged BioDiet

Length frequency distributions (Table 4) from the 50 fish total length
samples taken from each lot showed lots five and six to have the largest fish
and narrowest ranges. Little difference in average total lengths, distribu-
tions and ranges is noted between those lots fed by the same method, indica-
ting little diet effect. There was however, a significant difference in
average total lengths. Average total lengths of lots one, two and three
were significantly smaller than lots five and six. Lots three and four were
not statistically different. Ranges in total length were low in all groups
with lots one, five and six having the lowest spread. The lot one sample,
however, did not show any fish in the largest length class.

Table 4. Length frequency distributions, average total lengths, and ranges
for brown trout fed by three different methods and two different
diets.

Lot 4.0-4.9
1 16
2 18
3 12
4 2
5 0
6 0

Length class (cm) (%)
5.0-5.9 6.0-6.9

Av total
7.0-7.9 Igth (em)

Range

50
54
42
48
34
36

34
24
42
44
54
58

0 5.6+.18a
4 5.6+.20
4 b
5.8+.21
-
6 bc
6.0+.17
-
12 6.2+.17c
-
6 6.2+.16c

4.3 - 6.7
4.3 - 7.7
4.2 - 7.2
4.7 - 7.5
5.1 - 7.4
5.1 - 7.7

~.:!. 95% confidence interval for average total length
No statistical difference
CSignificantly larger at 95% level of significance

52