Small scale, only ventral cortex ventral fin and even anal with abdominal edge.

鳞小，腹面仅腹鳍甚至肛门具皮质腹棱。

Old World freshwater catfishes having naked skin and a long anal fin more or less merged with the eellike caudal fin.

东半球的淡水鲇鱼，体表无鳞，有类似鳗鱼尾鳍的很长的臀鳍。

In addition, the anal fin has a curvature that fits the round shape.

还有，尾鳍有一个弯曲度刚好适合鱼的圆型身体。

Old world freshwater catfishes having naked skin and a long anal fin more or less merged with the eellike caudal fin.

东半球的淡水鲶鱼，体表无鳞，有类似鳗鱼尾鳍的很长的臀鳍。

The sex can be identified base on the shape of anal fin, and there are some obvious pearl organs on anal fin of male individuals during reproduction seasons.

可根据臀鳍的形状来鉴别青海湖裸鲤的雌雄，在繁殖期间，雄性个体在臀鳍部位出现明显的珠星。