摘要
利用雄性四倍体鲫鲤与雌性二倍体红色双尾金鱼交配 ,制备了 1种新型三倍体鲫鱼 ,并对Ⅰ龄三倍体鲫鱼染色体数目和组型、性腺指数和性腺结构、外形、生长速度等生物学特征进行了系统研究。结果表明 :这种三倍体鲫鱼染色体数目为 3n =15 0 ,核型公式为 33m +5 1sm +33st+33t;在繁殖季节 ,三倍体鲫鱼卵巢和精巢指数明显低于作为对照的红鲫卵巢和精巢指数 ;组织学切片表明三倍体鲫鱼的卵巢和精巢不能产生成熟的卵子和精子 ,证明它们是不育的。三倍体鲫鱼体色为青灰色 ,单尾 ,具有一些介于其父母本———异源四倍体鲫鲤和红色双尾金鱼之间的外形特征 ,如具有 1对肉眼不易观察到的短须 ,侧线鳞式为 31 6 7,背鳍为 18,体高 体长之比为 0 5 ,比湘云鲫的体高 体长之比 (0 4 1)有明显的增加。经过约 8个月的饲养 ,该三倍体鲫鱼平均重量为 35 0g,最大个体达 5 5 0g。在Ⅰ龄鱼中 ,雌性三倍体鲫鱼的个体生长速度快于雄性个体。与三倍体湘云鲫相比 ,该三倍体鲫鱼保留了生长速度快、不育等优点 ,同时新添了体高 体长比值更高、肉质更甜美的特点 ,为
A new type of triploid crucian carp was generated by mating the males of the allotetraploid hybrids of red crucian carp (Carassius auratus red var.) (♀) ×common carp (Cyprinus carpio L.)(♂),with the females the goldfish(Carassius auratus red var.)which was red in color and possessed the biforked tails.The biological characteristics of one-year old triploid crucian carp including the number and karotype of chromosome,gonadosomatic indices and gonadal structures,appearance and growth rate were investigated.The results indicated that the triploid crucian carp possessed 150 chromosomes with the karyotype:33m+51sm+33st+33t.In the breeding season,the gonadosomatic indices (GSI) of the ovaries and testes in the triplpoid crcuian carp were,respectively,lower than those in the diploid red crucian carp,and the tissue sections showed that both the ovaries and the testes in the triploid cruican carp were not able to produce the mature ova and sperm,respectively,indicating that they were sterile during one year.The triploid crucian carp was gray in color and had a single fork tail.They had other morphological traits intermediate to the paternal allotetraploid hybrids and the maternal goldfish,for example,one pair of very short and not readily visible barbells,the formula of lateral line scales:31-6/7,18 dorsal fin spines,and 0.5 in ratio of the width to the length of the body which was evidently higher than that (0.41) in another kind of triploid crucian carp called Xiangyun crucian carp,generated by crossing the males of the allotetraploid hybrids with the females of the Japanese crucain carp (Carassius auratus cuvieri T.et S.).Following 8-month culture,the triploid crucian carp averagely reached 350 gram in which the maximum individual weighed 550 gram.Among one- year old triploid crucian carp,the females grew faster than the males.Compared with Xiangyun crucian carp,the new type of triploid crucian carp not only presented some advantages the Xiangyun crucian carp had,for example,fast growth rate and potential sterilit
基金
国家自然科学基金项目 (编号 :3 0 170 73 3
3 0 3 3 0 480 )
国家"973"项目 (编号 :2 0 0 1CB10 90 0 6)
教育部跨世纪人才培养基金 (编号 :2 0 0 2 48)项目资助~~
