| Abstract | Two experiments were conducted to study the
catfish use of artificial feeds in nursing walking (Clarias
macrocephal us) fry.
Experiment 1 was conducted to select a suitable diet for .Q..
macrocephalus fry. Four artificial diets, i.e. commercial powder
feed, fish me al, rice bran and a mixed diet of rice bran plus
fish meal (1 : 1 by weight) were tested as fry feeds for rearing .Q..
macrocephalus. The fry averaging 0. 1g were stocked in 24 circular
concrete tanks <1 2 in static and 12 in recirculated water
systems) of 1. 25m diameter and 0. Sm depth housed under a thatch
roof. The water depth was maintained at 0. 1 5m for the first 3
weeks and 0. 3m for the subsequent 2 weeks. The water flow into
individual tank in recirculated water system was maintained at
1 . OL/min., i.e. 4 exchange of total water a day. The fishes were
fed ad-libitum 4 times a day <8 . 00, 12. 00, 16. 00 and 20. 00 hours)
for the whole experimental period. The average final fish weights
and survival rates with fry fed commercial powder feed in static
and recirculated water systems were 1 . 65g, 53 . 33% and 1. 86g,
58 . 00%, respectively; for fish meal 1 . 37g, 48. 67% and 1. 33g,
50. 33%, respectively; for rice bran 0 . 42g, 28. 67% and 0 . 42g,
28 . 67%, respectively and the mixed diet 1. 35g, 45. 33% and 1. 13g,
46. 33%, respectively. The growth and survival was relatively low
with all the diets. However, the best growth and survival rate
was attained with the fish fed commercial powder feed in both
static and recirculated water systems. This is because of the
sticky and consistent nature of the diet which enabled fish to
consume it without wastage.
Experiment 2 was conducted to evaluate the effects of 3
stocking levels on the growth and survival of .Q.. macrocephalus
fry fed commercial powder feed in net cages. Twelve nylon net
cages ( 1 m x 1 m) were stocked with fry (averaging 0. 1 g) at 3
densities, i.e. 100, 200 and 400 fish/m2 • The fishes were fed a d -
libitum 4 times a day ( 8. 00, 1 2. 00 , 16. 00 and 20. 00 hr.) for 35
days. The average final weights of fish reared at 100, 200 and
400/m2 were 5 . 89g, 6. 01 g and 4. 65g, respectively. The survival
rate was found to be 52. 00%, 56 . 25% and 51. 1 3% at 100, 20 0 and
400 fish/m2 , respectively. The fry stocked at 200/m2 gave the
best results in terms of growth, survival and food conversion
efficiencies.
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