利用鱼类远缘杂交技术和雌核发育方法获得了新型四倍体鲫鲤(G1×AT).在G1×AT中发现2%的高背型个体,其自交后代性状发生分离并形成3种两性可育的二倍体鱼:高背型红鲫、高背型双尾金鱼和青灰色鲤鱼.其中高背型红鲫自交,后代性状继续发生分离,形成高背型红鲫、花鲫和青鲫.本文主要对这3种高背型鲫鱼及其自交后代的外形特征、染色体数目、性腺显微和超微结构以及繁殖力等方面进行了研究.结果表明:(ⅰ)这3种高背型鲫鱼在外形上都具有体背高、尾柄短、头部小的优良特性.高背型红鲫、花鲫和青鲫的体高/体长值分别为0.54,0.51和0.54,三者明显高于普通红鲫的体高/体长值0.41(P<0.01);(ⅱ)3种高背型鲫鱼染色体数目与普通红鲫染色体数目一致,都为2n=100;(ⅲ)这3种高背型鲫鱼都具有正常的卵巢和精巢,它们分别能产生成熟的卵子和精子,为二倍体高背型鲫鱼品系的形成奠定了基础;(ⅳ)与普通红鲫相比,3种高背型鲫鱼具有产卵(产精)量大、繁殖期长、受精率和孵化率高等优点.它们通过自交培育出了具有高背特征的二倍体鲫鱼群体;(ⅴ)3种高背型鲫鱼既具有较高的观赏和食用价值,也可以作为优良的二倍体亲本与四倍体鱼交配来制备高背型三倍体鲫鱼.这3种高背型鲫鱼的形成在生物进化研究和鱼类遗传育种研究方面都具有重要意义. A new tetraploid crucian carp (G1 × AT) was obtained by means of distant hybridization of fish and gynogenetic method, and 2% of high-dorsal individuals were found in G1 × AT, and their self-progenies were segregated to form 3 Species of diploid fertile diploid fish: high-dorsal red crucian carp, tall-backed two-tailed goldfish and blue-gray carp, of which high-dorsal red crucian carp self-generation, offspring traits continue to segregate to form high-dorsal red crucian carp Crucian carp and crucian carp.In this paper, the appearance, chromosome number, gonad microstructure, ultrastructure and fertility of these three species of crucian carp and their selfed offspring were studied.The results showed that: (i) All the three species of high-back crucian carp had the characteristics of high body back, short caudal peduncle and small head in their appearance.The body height / body length of high-back type red crucian carp, crucian carp and green crucian carp were 0.54,0.51 and 0.54 (P <0.01). (2) The chromosome numbers of the three species of high-back crucian carp were the same as that of the common crucian carp, both of which were 2n = 100; (iii) These three species of high-back crucian carp have normal ovary and testis, they can produce mature eggs and sperm, respectively, for the diploid high-back crucian carp strains (Ⅳ) Compared with the common red crucian carp, the three species of crucian carp had the advantages of large spawning (fertilization), long breeding period, high fertilization rate and hatching rate, etc. They were bred by selfing Diploid crucian carp with high back features; (iv) Three high-back crucian species not only have high ornamental value and edible value, but also can be used as excellent diploid parents and tetraploid fish mating to prepare high back Triploid crucian.The formation of these three species of crucian carp is of great significance in the research of biological evolution and the research of fish genetics and breeding.