尾鳍

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

具体来说，半月斗一定要具备开展朝向前方，180°上鳍。

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

在大多数鳍，沿著背侧与腹侧缘前部具有无条痕鳍条。在一些中，例如其有条痕与无条纹软条数量比在鑑定上是有帮助。