TRIPLOIDIZATION OF COHO SALMON FOLLOWING APPLICATION OF HEAT AND ELECTRIC SHOCKS

The effectiveness of heat shocks in combination with electric shocks, derived from either alternating (AC) or direct sources (DC) ( 10 V), w as compared with respect to their ability to induce triploidy in coho salmon. Electric shocks were applied to eggs for 2.5, 5.0 and 10 min d uration, and for 10, 20 and 40 min post-fertilization, at 10 and 26-de grees-C. Control eggs received identical handling and heat treatments but without electric shocks. Treatment of developing embryos with AC c urrents was more effective in including triploidy than with DC current . AC shocks of 10 min duration, delivered to eggs held at 26-degrees-C , 40 min post-fertilization, produced 100% triploidization versus 70% and 15% observed in DC and control studies respectively. Ploidy states were verified by flow cytometric analyses.