鳡鱼(♂)和赤眼鳟(♀)杂交F_1胚胎发育研究

Study on embryonic development of hybrid F_1 by Elopichthys bambusa(♂])× Squaliobarbus curriculus(♀)

以鳡鱼（Elopichthys bambusa）为父本,赤眼鳟（Squaliobarbus curriculus）为母本进行属间人工远缘杂交,对杂交F1胚胎发育情况进行了观察和记录,描述了各发育阶段的形态特征。鳡鱼（♂）和赤眼鳟（♀）杂交F1受精卵的平均受精率为（72.13±13.42）%,平均孵化率为（27.40±3.96）%;杂交F1的受精卵为晶莹半透明的圆球形,平均卵径为（0.978±0.028）mm,吸水膨胀后平均卵径为（3.740±0.055）mm,为非粘性半浮性卵;胚胎发育分为受精、卵裂和囊胚、原肠期、神经胚、器官形成期、孵化期6个阶段,其中包括30个主要时期,在温度为25~26℃的孵化条件下,杂交F1受精卵经23 h 40min孵出仔鱼,总积温为611.58℃.h。结果表明：鳡鱼（♂）和赤眼鳟（♀）杂交F1的受精卵可以正常发育,可正常孵出仔鱼,但其杂交亲和程度不高;杂交F1胚胎发育与母本赤眼鳟的发育差别较小,表现出较强的趋母性遗传的特征。

The hybridization between Elopichthys bambusa（♂]） and Squaliobarbus curriculus（♀） was conducted by artificial propagation.A series of normal stages based on morphological features for the embryonic development of the hybrid F1 was described.Average fertilization and hatching rate of the hybrid F1 were（72.13±13.42）% and（27.40±3.96）%,respectively.The fertilized eggs were spherical in shape,glittering and translucent,with average diameter of（0.978±0.028）mm.When they were expanded by adsorption of water,they had the average diameter of（3.740±0.055）mm and were non-adhesive and semi-floating.The total process of embryonic development could be divided into 30 periods which belonged to 6 stages as follows：fertilized stage,cleavage and blastoderm stage,gastrulation stage,neurula stage,organogenesis stage and hatching stage.Accumulative temperature during incubation was 611.58 ℃·h and hatching was completed in 23 h and 40 min at the temperature of 25~26 ℃.The results showed that the fertilized eggs of hybrid F1 of E.bambusa（♂]） and S.curriculus（♀） were able to develop regularly and the larvae of hybrid F1 were hatched out normally,but there was a low cross-compatibility to a certain extent for the hybrid F1.The overall embryonic development process and the morphological characters were closer to those of its maternal fish,S.curriculus,which showed significant characteristics of maternal inheritance.