鲫鱼的人工和天然雌核发育

用照射处理的草鱼或华南鲤的精液授精的鲫鱼卵为单倍体雌核发育;所有单倍体胚胎都是畸形,并在孵化前死亡。如果用照射精液授精的鲫鱼卵在18—19℃的水中放置2分钟,然后在0—3℃的冰水中放置20分钟,再放回室温水中孵化,可以从每百颗受精卵中得到4.5—11.9(平均8.34)尾成活的二倍体仔鱼。根据38尾银鲫(其中33尾捕自黑龙江省方正县双凤水库)的细胞学和胚胎学检查,证实它们是雌核发育繁殖的。  

ARTIFICIAL AND NATURAL GYNOGENESIS IN CRUCIAN CARP

The purpose of this investigation is to examine the feasibility of using ultraviolet irradiation for producing gynogenetic diploid goldfish (Carassius auratus) and to look for the naturally gynogenetic population of crucian carp (Carassius auratus gibelia) in our country.The eggs of goldfish inseminated with irradiated milt of grass carp (Ctenopharyngodon idellus) or Hua-nan carp (Cyprinus carpio rubrofuscus) began with a haploid gynogenetic development. All haploid embryos, however, were abnormal in development and died before hatching. If goldfish eggs were held for 2 minutes in water of 18°—19℃ after addition of irradiated milt, followed by exposure to 0°—3℃ water(with crushed ice) for 20 minutes and then incubated at room temperature, we could obtain 4.5—11.9% (average 7.4%) viable diploid fry.The results of embryonic examination of thirty eight crucian carp (among them thirty three were caught from Shuangfeng reservoir in Fangeheng County. Heilong-jiang Province) proved that all of them reproduced by natural gynogenesis.Finally, the teratogenic effect of irradiated spermatozoon on gynogenetic haploid embryos is discussed.