| Author | Suresh, Arul Victor |
| Call Number | AIT Thesis no. AE-90-29 |
| Subject(s) | Tilapia
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Red tilapia with an average size of 75 g were reared in
concrete circular tanks at densities of 50, 100 a nd 200 fish/m3
in a recirculated water system for 70 days. At a loading rate of
1 L/kg fish/minute a nd a feeding rate of 1. 5% body we ight/day
with 22% protein commercial pellets , the individua l fish growth
rate and feed uti1ization efficiency we re inversely related to
increasing stocking density. However, there were no significant
differences between these parameters at the medium and high
densities . The net yields increased log arrhythmically with
increasing stocking density. Partial budget analyst is showed that
the medium density was the most economical . Behavioral studies
indicated that the growth-inhibiting agonistic behavioral
patterns we r e genera11y unabated even at the highest stocking
density. Use of constant loading rates maintained almost similar
and safe water quality levels in all treatments.
A reconditioning system with plate interceptors in the
sedimentation chamber and an up flow biofiltration unit, was used
to treat the waste production in t he culture units. The gross
oxygen consumption a nd t he ammonia and total so1ids production
rates of the stock were estimated to be 2. 13, 0.61 and 5.68 g/kg
fish/day respectively. The overall removal efficiencies for
various water quality parameters fluctuated and s lightly imp roved
with time. An accumulation of organics in the reused water was
observed .
The overall performance of fish production in the
recirculation system was poor . The daily weight gains were in the
order of 0.77, 0 .65 and 0.64 g/fish in the low, medium and high
stocking densities respective 1 y, a nd t he respective net yie1ds
were 27.01 , 40.98 a nd 57.37 g/cu . m/day. Mortalities ranged from
13 to 21% and subsequently affected the overall food conversion
ratio ( FCR ). The FCR values were 2.38 , 3. 08 a nd 4.28 in the low,
medium and high stocking densities respectively . |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Lin, Chang Kwei |
| Examination Committee(s) | Little, David C. ;Yakupitiyage, Amararatne
|
| Scholarship Donor(s) | Government of United Kingdom |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1990 |