| Author | Rab, Md. Abdur |
| Call Number | AIT Thesis no. AE-89-33 |
| Subject(s) | Nile tilapia fry
|
| Note | A Thesis submitted in partial fulfilment of the requirements of the degree
of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Tilapia , although popular for its favorable characteristics, high
yield and high market demand , faces t he problem of intensive production,
especially in pond breeding condition. To overcome this, artificial incubation is being tried in some places. One such system has been developed
in AIT, where an incubation system has grave l pre-filter and slow-sand
filtration units. But the eficiency and capacity of t he fry nursing system
under intensive nursing has not yet been done . The present study intends
to fill this gap .
The present study was carried out on just-hatched and on swim-up fry
of Oreochromis niloticus under intensive nursing within a re- circulated
system in aluminum trays (2 . 4 litre capacity). The system has no water
filtration facility . Feeding was maintained ad-libitum on yolk sac fry
and at 20%, 30% and 40% BW/day on swim- up fry. Feeding frequency was
maintained at 5 times a day. Both the experiments were conducted using
randomized design.
From t he period of just-hatched to swim- up, t he optimum flow rate for
the system would lie between 3 and 5 litre/minute. But in view of the
limitation of the system capacity, 3 litre/minute flow rate is considered
the best to estimate system capacity in respect of fry growth and survival. Of artificial versus natural hatched fry results show that artificially hatched fry perform slightly better than naturally hatched fry
in survival, Specific Growth Rate, Percent Weight Gain and Daily Weight
Gain. For early nursing a feeding level of 40% body weight per day is
found to be the optimum one for swim-up fry. In yolk-sac fry survival and
growth parameters maintain a positive relationship with density in lower
flow rates and inverse at higher flow rates, in swim-up fry the relationship is inverse. Mean observed mortality percent of swim-up fry
is positively related to density and inversely to feeding l evel, and is
enhanced by an infection of Trichodina spp . Cannibalism accounted for a
mortality rate of 0 . 47- 9 . 60% of the original density and is inversely
related to feeding level. |
| Year | 1989 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Little, David C.
; |
| Examination Committee(s) | Machintosh, Donald J. ;Yakupitiyage, Amararatne ; |
| Scholarship Donor(s) | British Technical Assistance; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1989 |