GYNOGENESIS IN THE BLACK CARP, MYLOPHARYNGODON-PICEUS

Gynogenesis was induced in the black carp, Mylopharyngodon piceus, by activating black carp eggs with sperm of heterologous cyprinids with a different number of chromosomes. Such crosses normally result in nonv iable progeny. Saline diluted (1:9) and UV-irradiated (800 J/M2) sperm of Japanese ornamental (koi) carp, Cyprinus carpio, and intact sperm of goldfish, Carassius auratus, were used to inseminate batches of bla ck carp eggs. Diploidy was restored by retention of the second polar b ody by means of heat shock (41.0+/-1.0-degrees-C for 1 min), applied a t various biological ages determined by the factor (tau0) empirically established for black carp.