acinaciform

例句：

1. 1. The acinaciform fin is found in many fish species.
   许多鱼类物种都有这种鳍状的鳍。
2. 2. The acinaciform scales are used for protection and defense.
   这种鳞片用于保护和防御。
3. 3. The discovery of acinaciform fossils has shed new light on the evolution of marine life.
   发现化石揭示了海洋生物进化的新视角。