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作者对分布于北京市怀柔区怀九河的宽鳍鱲(Zacco platypus)的胚胎发育及仔鱼前期发育进行了研究,过程中采用人工干法授精获取受精卵,观察并描述了宽鳍鱲早期发育过程及其特点。结果显示,宽鳍鱲成熟卵呈圆球状,平均卵径1.04 mm,为沉性卵。在平均23.0℃(17.1—28.0℃)水温条件下,从受精卵到孵化经历了73h1min,积温为1682.3度.时;孵化后6.5d进入弯曲期仔鱼。仔鱼前期发育速度与出膜前相比明显减慢;弯曲期仔鱼出现大量死亡可能与有限的人工培育条件、混合营养期能量供给不足等原因有关。通过比较发现,宽鳍鱲与鲤科中其他21个种相比,早期发育时间比其中7个种均长。宽鳍鱲早期发育时间比同域分布、相同发育水温的马口鱼略长,明显长于同属的纵纹鱲的发育时间。宽鳍鱲南、北方种群仔鱼发育速度存在差异,北方种群出膜前发育速度比南方种群快,但出膜后发育速度减慢。
The author studied the embryonic development and pre-larval development of Zacco platypus distributed in Huaijiu River, Huairou District, Beijing. Artificial dry insemination was used to obtain fertilized eggs, and the early development of broad-finned fishes was observed and described Process and its characteristics. The results showed that the mature eggs of C. maxima were spherical, with an average egg diameter of 1.04 mm, which was a sinking egg. Under the average water temperature of 23.0 ℃ (17.1-28.0 ℃), the larvae hatched from the fertilized eggs for 73h1min, the accumulated temperature was 1682.3 ℃, and reached the bending stage after 6.5 days. The larval development speed of larvae obviously slowed down compared with that before larvae. The large number of larvae died during bending period may be related to limited artificial cultivation conditions and insufficient supply of energy in mixed nutrition period. By comparison, the results showed that, compared with the other 21 species of Cyprinidae, the length of early development was longer than that of 7 species. The early developmental time of C. maxima was slightly longer than that of the homoplasia and the same developmental water temperature, which was significantly longer than the developmental duration of the same species. There was a difference in the developmental speed of larvae between southern and northern populations of P. variabilis. Northern populations developed faster than southern populations before they were out of the membrane, but developed slowly after they were out of the membrane.