Determination of triploid production using cold shock induction in clarias gariepinus

Abstract

This study was conducted to evaluate the differences between embryonic development and early growth of diploid and triploid induced African catfish (Clarias gariepinus). The objectives were to determine the embryonic development of triploid larvae and to determine triploid production using cold shock induction. The induction used in this study was cold shock induction which involved immersing fertilized eggs into 5°C and 10°C water for 45 minutes starting 5 minutes after fertilization. The hatching rate obtained was 95%, 32% and 30% for control replicate, 10°C and 5°C induction treatments respectively. However there was no significant difference between hatching rate of 10°C and 5°C induction. The triploid rate obtained was 80% and 90% for 5°C and 10°C inductions respectively. However there are no significant different of in term of triploid obtained for both inductions temperature regimes. There are no differences in term of embryonic development for all treatment. However, eggs from 5°C induction treatment hatched 2 hours earlier (17 hours AF) compare to control and 10°C inductions (19hours AF). Several deformities were observed for 5°C inductions larvae. The deformities observed might be due to the mechanical shock during embryo or larval development. In conclusion, the triploid production in C. gariepinus using cold shock induction yielded high triploid rate and this can be done either using 10°C or 5°C with the same level of probability to obtain triploid fish.