dc.description.abstract |
Stocking density is considered one of the important factors that affect the growth and
production of fish. However, information related to the effect of stocking density on the
growth performance and production of mono-sex Oreochromis niloticus in pond culture
conditions has not been well studied in Ethiopia. Therefore, this study aimed to compare
the growth performance and production of mono-sex tilapia at various stocking densities
and to determine an ideal and economical stocking density for the culture of mono-sex
O.niloticus fingerlings. Male fingerlings were isolated by examination of the genital
papilla region and stocked in three stocking densities 3, 5, and 7fingerlings/m
in
triplicates. The initial mean weight had 26.31 ± 0.06, 26.28 ± 0.08, and 26.33 ± 0.1 g, for
3, 5, and 7fingerlings/m
2
,respectively, and grown for six months in a 10m
concrete pond
for each. The gains in weight and water quality parameters were recorded monthly. The
final mean weights (±SE) of the fingerlings stocked at densities of 3, 5, and 7 fingerlings
were 182.58 ± 0.39, 163.33 ± 0.78, and 153.57 ± 0.34 g, respectively. The specific and
daily growth rates for densities of 3, 5, and 7fish were 1.11, 1.05, and 1.01% and 0.9,
0.79, and 0.73 g per day, respectively. The total biomass production obtained at the end of
the experiment was 5.11, 7.57, and 9.78 kg for densities of 3, 5, and 7fish/m
, respectively.
The food conversion ratio (FCR) varied from 2.98 to 3.15, and the best FCR was obtained
for 3fish/m
2
(2.98). The dissolved oxygen and ammonia were between 6.7 and 5.08 mg/L
and 0.11 g/L to 0.18 g/L respectively. Except for temperature and salinity other water
quality parameters showed significant differences between stocking density. The highest
net profit was obtained for the stocking density of 7fish/m2. The overall results emanating
from this study indicate that even if a higher growth rate was obtained at the lower
stocking densities after ending the trial period a high stocking density of 7 fish/m
gave a
significantly higher yield or production/m
2
and contribute to the highest present of net
profit (42%) than 3 fish/m
2
(37.7%) and 5 fish/m
2
(23.9%) and can be very useful to give
good returns for local consumption and efficient utilization of resources. Therefore further
study should be conducted to investigate better stocking density beyond 7fishes/m
whether it will be possible to get more yields per unit area. But need optimum
management levels are necessary to fish growth under high-density systems.
2
2
2
2
2
and |
en_US |