INDUCED GYNOGENESIS AND POLYPLOIDY IN THE ISRAELI COMMON CARP LINE DOR-70

Meiotic and mitotic diploid gynogenetic, triploid and tetraploid proge nies were obtained in the Israeli common carp (Cyprinus carpio L.) lin e Dor-70 in laboratory experiments and in large scale production in We iss incubation jars. Chromosome-set diploidization was induced by heat shock applied at the second meiotic division or at the first cleavage . A high rate of response to induction of diploid gynogenesis was obse rved. The best production was 29% meiotic gynogenetic larvae and 23% m itotic gynogenetic larvae (of fertilized eggs). About 10,000 meiotic g ynogenetic larvae and 40,000 mitotic gynogenetic larvae were obtained from mass production experiments. Survival of gynogenetic progenies to age 2.5 months under pond conditions was 8% for meiotic gynogens and 3% for mitotic gynogens. A large number of mitotic gynogenetic fingerl ings had morphological aberrations. The frequency of triploid larvae w as 83-100% and that of tetraploid larvae 92-100%, in the most successf ul experiments, but heat shock resulted in markedly decreased larvae s urvival. Many tetraploid larvae were weak and/or deformed, and only tw o tetraploids were found (among 31 surviving fish) after two months re aring in ponds.