鲮的胚后发育

Post-Embryonic Development of Cirrhinus molitorella

经人工授精获得鲮(Cirrhinus molitorella)受精卵,观察其胚后发育,描述9个主要发育期的仔鱼形态特征。结果表明,鲮胚后发育的主要特征是:身体较为透明,淡黄色,体形短小,孵出时,体长4.7mm,肌节数36(10+16+10);鳔一室期后,其胸鳍基部有2～3个黑色素花,头部较为尖突,尾柄下具黑斑;出膜5d后,全长7.1mm,卵黄被完全吸收,尾锥开始上翘;经过25d的生长和发育,进人幼鱼阶段,此时平均全长达30.1mm,初步呈成鱼体征。为监测及保护珠江水系早期鲮鱼资源,讨论鲮与其他几种常见鱼类胚后发育形态差异。

From May to June of 2008, artificial propagations of mud carp （Cirrhinus molitorella） were carried out to obtain fertilized eggs for the observation on the postembryonic development. The development was divided into 9 stages on the basis of the external morphology, internal morphogenesis, each stages was described and photographed. The characters of mud carp is very obvious as followed： The body is somewhere transparent, with few pigment; Total length is about 4.7 mm after hatched, and muscle nodes is about 36pairs; There are some pigment on the pectoral fin, and after chordal tip lifting stage, there are some pigment aggregated below the caudal peduncle. Total length was 7.1mm at 5 days post-fertilization, the yolk sac was exhausted, and the end of the vertebral column curved upward. After developing and growing for 25 days, with formation of all fins, the fry have the characters of the adult mud carp. For the need of investigation of the fry of mud carp in the Pearl River, the development character was also compared with several others fish.