anal fin

Any of various freshwater fishes of the family Cyprinidae related to the carps and minnows, especially a Eurasian species, Leuciscus cephalus. "It has one dorsal and one anal fin, Both long and Both connected to the rounded tail."

白首鲤一种相关于鲤鱼和鲦鱼的鲤科淡水鱼，尤指欧亚品种，圆鳍雅罗鱼背鳍和臀鳍各一，形长，均与尾鳍基部相连，尾鳍圆形

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。

Anterior portion of anal fin with narrow black margin.

第一背鳍相当黑色，末梢部白色的与基部地。

Anal fin rays ii, 5;

臀鳍ii，5；

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。