Abstract
Triploidy could reduce breeding activity in tilapia without the use of hormones. In this study, the effect of triploidy on survival, growth, and gender of a line of red hybrid tilapia (Oreochromis mossambicus X Oreochromis niloticus) was assessed relative to the performance of diploid siblings. Triploidy was induced by preventing second polar body extrusion by applying either heat or cold shock. Growth was similar for both ploidies during the first 90 days of culture. However, at the age of 120 days, the average body weight of triploids produced by heat shock (215.5 ± 3.61 g) was significantly higher than that of cold shock (192.7 ± 2.6 g) and the diploid control (191.9 ± 1.74 g). Survival among triploids was inferior to diploids. Percentage of males in the triploid population was 82.9% in the heat-shocked treatment group, 54.8% in the cold-shock treatment, and 50% in the diploid control. Maximum attainable weight of red tilapia was calculated by applying the Ford-Walford growth plot: 650 g (heat-shocked triploids), 490 g (cold-shocked triploids), and 440 g in the diploid control.
Notes
The authors are grateful to the Director Professor Faizha Shaharom, Institute of Tropical Aquaculture, University Malaysia Terengganu, for providing laboratory facilities. Padmaja J. Pradeep and Thekkeparambil C. Srijaya are grateful to University Malaysia Terengganu for the award of research assistantships and Anil K. Chatterji is grateful for the award of a Principal Research Fellowship. The authors are also thankful to two anonymous reviewers critical comments to improve the quality of the article. The authors express their sincere appreciation for the comments given by the reviewers to improve the article.