Tetraploid induction by heat shocks in Chinese shrimp, Fenneropenaeus chinensis

Tetraploid induction in the Chinese shrimp Fenneropenaeus chinensis was studied. Tetraploid larvae were successfully produced through mitosis I inhibition by heat shock in this species. Proper time window for tetraploid induction was optimized, and the highest induction level was more than 90% as measured by flow cytometry. At spawning temperature of 16degreesC, the best starting time for heat shocks was 98 to 110 min postfertilization. Tetraploid embryos had less viability compared with diploids. The highest tetraploid level detected at nauplius stage was 38%. Further work is needed to increase the viability of tetraploid larvae.