| Author | Barman, Benoy Kumar |
| Call Number | AIT Thesis no. AE-90-38 |
| Subject(s) | Fish stocking
|
| Note | A thesis submitted in partial fulfilment of the requirements
of the degree of Master of Science, School of Environment, and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-90-38 |
| Abstract | Three experiments were conducted to study the nursing of
fish try in nylon hapas in earthen pond with a duration of 4
weeks for each.
Experiment 1 was conducted to compare the growth and survival of MT(Methyl testesterone) treated Nile tilapia(preochromis
niloticus) fry nursing at high stocking densities. In 5.4m~ nylon
hapas try were stocked at 500/m2, 750m2 , 1000m2 and 1250m2 stocking densities and nursed for 4 weeks. The mean final weight of
the fish at different stocking densities were 1.91g, 1.47g, 1.27g
and 1.17g respectively and the survival rate were 55.4%, 56.5%,
57.8% and 45.8% respectively. Both mean final weight and survival
rate for different treatments were significantly different
(p<0.01). Growth a nd survival rates were very l ow in all the
treatments probably because of poor water quality inside the hapa
and the pond itself.
Experiment 2 was conducted to determine the effects of
stocking density and ratio on the growth and survival of silver
barb(Puntius qonionotus) and mrigal (Cirrhina mrigala) fry nursed
in polyculture in nylon hapas(area 20m2 ). A factorial design was
used in which fry were stocked at 50/m2, 100/m2 and 200/m2 stocking densities a nd 1:1 and 2:1 ratio of silver barb and mrigal in
nylon hapas. The fry were nursed for 4 weeks. The mean final
weight of the fry at different stocking densities were 2.50g,
2.30g, 1.16g a nd 2.46g, 1 .88g, 1.77g respectively. The survival
rate of silver barb and mrigal at three different stocking densities were 94.8%, 78.0%, 78.2% and 7 1 .0%, 73.3% and 66.3% 1respectively. Silver barb at 1: 1 ratio showed the highest growth but
mrigal performed better at 2:1 ratio. The interaction effects of
stocking density and ratio on the growth and survival rate of the
fry were ·not significant (p >0.05). The water quality both inside
and outside the hapas was within favourable limits of both silver
barb and mrigal.
Experiment 3 was conducted to determine the effects of
stocking density and hapa size on the growth and survival of MTtreated Nile tilapia, silver barb and mrigal. In 5.4mL and 20m2
nylon hapas fry were stocked at 49/m2 , 99/m2 , 197/m2 and 394/m2
stocking densities a nd nursed for 4 weeks. All the three species
showed faster growth at lowest stocking density. The mean weight
of tilapia, silver barb an d mrigal at lowest stocking density
were 3.22g, 4.63g a nd 5.04g respectively. The growth of tilapia
in small sized hapas was higher than the large hapas whereas the
growth of silver barb a nd mrigal in large sized hapas were higher
than small hapas. The effects of hapa size on the growth of
tilapia, silver barb and mrigal were highly significant(p<0.01).
but the effect of hapa size on the survival rate of the fry were
not significant. |
| Year | 1990 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-90-38 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Little, David C.
; |
| Examination Committee(s) | Machintosh, Donald J. ;Knud-Hansen, Christopher F. ; |
| Scholarship Donor(s) | British Technical Assistance ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1990 |