尾鳍

Specifically, a halfmoon betta must have a caudal where both ends are exactly180 degrees apart or more, spreading towards the front.

体来说，半月斗鱼一定要展朝向前方，180°上的尾鳍。

Most fishes have unstriated rays along the anterior part of the dorsal and ventral edges (leading edges) of the caudal fin.

大多数鱼类的尾鳍，沿著背侧与腹侧缘的前部有无条痕的鳍条。一些鱼中，例如鰕虎鱼其有条痕的与无条纹的软条数量定上是有帮助的。