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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Induced Polyploidy in Nile Tilapia, Oreochromis nilotlcus, Through Thermal Shocks

(Thailand), Master of Science in Genetics (University of the Philippines Los Baños)

Thesis Abstract:

 

Buserelin acetate (Superfact nasal) alone or in combination with Domperidone (Motelium-M) (5-50 ug BA per kg body weight and 2-3 mg Oomperidone per 1 kg) were ineffective agents for inducing spawning in 0. niloticus. Spawning of 0. niloticus occurred by stocking ripe females in the aquarium for 3-4 weeks. The eggs from stripped spawners were subjected to artificial fertilization following the dry method.

Thermal shocks (11°C for cold shocks and 41 oc for heat shocks) on post-fertilization time (developing egg) of 2-15 min for various durations of shocking at 7-30 min of cold shocks and 2-5 min of heat shocks produced triploid 0. niloticus. The highest production of triploid hatchlings (64.3%) was derived after three minutes of heat shock treatment at 41 oc and at five minutes post-fertilization. In cold shock treatment at (11°C) for 30 minutes, only eight percent triploids were produced. Although some treatments also produced triploid hatchling of O. niloticus, these resulted in rather less triploids with high mortality rate.