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，沿著腹缘的前部有无痕的鳍。些鱼中，例如鰕虎鱼其有痕的无纹的软数量比鑑定上是有帮助的。