| Author | Ramachandran, Sarulatha |
| Call Number | AIT Thesis no.AQ-05-32 |
| Subject(s) | Nile 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 |
| Series Statement | Thesis ; no. AQ-05-32 |
| Abstract | Previous studies demonstrated the potential of a short term immersion protocol using ultrasound to more predictably produce all male tilapia in a laboratory experiment. This set of experiments explored the commercial application of ultrasound to produce all male population by increasing the numbers of fry per treatment in short treatment duration. Two 3X2X2 CRD factorial design of three fry densities (50, 100 and 200 fry/unit) were immersed in two different hormones (MT and TBA) with or without ultrasound for 1.5h or 2h duration. In Experiment with TBA 100g/L 2.0 hrs treatment duration produced significantly higher percentage of males than 1.5 hrs treatment duration. While in MT 100g/L experiment treatment duration increases male percentage but it has no any significant effect on sex reversal. TBA 100g/L 1.5 hrs and 2.0 hrs treatment duration experiments produced significantly higher male percentage (97.91%). Ultrasound treated 50 fry density with TBA 100g/L in 2.0 hrs resulted in 97.91% of male percentage, while 1.5hrs duration gave 96.45% males. Likewise 100 and 200 fry/unit resulted 89.61% and 89.27% of males respectively in 2.0 hrs duration while 1.5 hrs duration produced 88.36% and 86.54% of males respectively for 100 and 200 fry/unit treatment densities. Within MT treatment best results were obtained with 50 fry/unit, in100g/L MT in 2.0 hrs treatment (92.02%). Treatment duration of 1.5 hr resulted lower percentage of males (83.00%) In general, TBA produced higher male percentage than MT immersed with ultrasound. Ultrasound immersion combinations produced more males than without ultrasound. Without hormone ultrasound alone had some effect on sex inversion and it produced higher male percentages than hormone immersion only without receiving ultrasound application. This study indicated that the 50 fry/ unit with MT or TBA (100g/L) forl.5 hrs treatment duration may be economically viable than the previous protocols recommended. Since the treatment duration has a significant effect on sex reversal for TBA (100g/L) experiments a detail economic evaluation must be carried out to find out the economically efficient treatment duration |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AQ-05-32 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Bart, Amrit; |
| Examination Committee(s) | Yakupitiyage, Amararatna;lkejima, Kou;Yi, Yang; |
| Scholarship Donor(s) | Government of Norway; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2005 |