Induced Tetraploidy in Grass Carp (Ctenopharyngodon idella Val) by Heat Shock

Abstract

Tetraploid grass carp (Ctenopharyngodon idella Val) were produced by heat shock to the eggs before first cleavage. Heat was applied 0-20 min. before cleavage at 39-42"C for 1-4 min. The highest percentage of tetraploids (42%) was at 40"C for 2 min., 10 min. before first cleavage. The effect of temperature on embryo survival is described.