| Author | Nguyen Minh Thanh |
| Call Number | AIT Thesis no. AS-98-08 |
| Subject(s) | Carp
|
| 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 | Methods of cold shock and heat shock for i_nduction of triploidy in common carp
( Cyprinus carpio) were investigated in the first experiment which determined the optimal
treatment schedule providing a high yield of triploidy . The series of cold shock treatments
evaluated were combinations of temperatures of 0 or 2°C, shock durations of 30 or 40 min and
shock initiation at 5 or 9 min after fertilization (a.f.). In the case of heat shock, treatments
combined of temperatures of 40 or 4 I °C, shock durations of I. 5 or 2 min and start times of 4
or 6 min a.f.
The technique of DNA microfluorometry with DAPI staining was developed to
determine ploidy using tissue from I-day post hatched fish in order to obtain results early
enough for them to be used in the design of follow up experiments. The ploidy level
determined by the microfluorometry was intended to be verified by the more reliable technique
of measurement of the major axis of blood cell nuclei in blood samples collected from older
fish. However, blood cell nuclei measurement could not be accessed due to loss of reared fish.
The cold shock treatment of 0°C, at 5 min a.f, lasting 40 min and the heat shock
treatment of 4 I °C, at 4 min a.f. and exposure of I .5 min gave the best results in term of
triploid yield . Survival of I-day post hatched larvae of 86% and 98% were obtained from cold
and heat shock treatments respectively whilst triploid yields were 77% and 63%. Of the three
major parameters implicated in triploid induction, temperature of shock and duration of shock
performed were clearly most important in terms of triploid yield.
The optimal treatment of cold shock and heat shock were carried out in triplicate in the
third experiment for comparison of their efficiency in induction of triploidy . This experiment
demonstrated that the degree of maturation of the eggs and the quality of sperm might account
for variable and often very low survival and variable triploid yields. The optimal heat shock
treatment resulted in very low triploid yields ranging from 11 % to 30%, whilst all cold
shocked eggs died.
Triploid and diploid fish were grown in hapas suspended in an earthen pond for
comparison of survival and growth rate during the early nursing stage up to six weeks.
Survival and growth rate in the heat shocked progenies were lower than those in the
corresponding control progenies during the early nursing stage. |
| Year | 1998 |
| 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 Systems & Engineering/Former name = Agricultural & Aquatic Systems(AS) |
| Chairperson(s) | Mair, Graham C.; |
| Examination Committee(s) | Edwards, Peter ;Yakupitiyage, Amararatne ; |
| Scholarship Donor(s) | DANIDA; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1998 |