ANDROGENESIS IN COMMON CARP (CYPRINUS-CARPIO L) USING UV IRRADIATION IN A SYNTHETIC OVARIAN FLUID AND HEAT SHOCKS

Haploid androgenetic offspring (max. 53.9%) were obtained after UV-irradiating eggs using dosages of 150-300 mJ/cm2 (duration: 135 to 270 s at an intensity of 1.1 mW/cm2). During irradiation, eggs were stirred in a synthetic ovarian fluid to assure a homogenous irradiation of all pronuclei, without activating the eggs. Androgenetic origin was checked using a recessive colour marker (''blond''). Absence of black fry (dominant trait) in the offspring confirmed inactivation of the female genome. Besides androgenetic haploids, few biparental diploids hatched at the optimal dose (250 mJ/cm2). Diploidy could be restored by heat shocks (40.0-degrees-C, 2 min) applied at different times after fertilization (26, 28 and 30 min). Yields of putative androgenetic diploids ranged from 7.2 to 18.3% at the time of hatching. Also, survival of the larvae 24 days after hatching was high (78-89% of the initial number). After testing the homozygous nature of the fish, they will be used to generate isogenic strains.