No abstract

Triploidy in embryos of the Chilean northern scallop, Argopecten purpuratus Lamarck, 1819, was induced with heat shock. Ploidy levels were assessed by chromosome counting after 3 h from embryos at the 8-16 cell stage of development. The efficiency of induction varied with the time of treatment post-insemination and the temperature of the shock. The duration of the shock showed a positive correlation with the percentage of triploids, the highest of which was obtained using 31°C for 15 min applied 10 min after insemination (66.7 %) but with low percentage of survival embryos after 3 h (26.4 %) and 18 days (11.2 %). The optimal procedure for triploidy induction (62.7 %) and survival after 3 h (62 %) and 18 days of culture (30.5 %) was the heat shock of 31°C for 10 min applied 10 min after fertilisation. We observed no significant difference in growth of shell length between controls and treated larvae after 18 days of culture.