月尾刺尾鱼 Acanthurus bahianus yuè wěi cì wěi yú

月尾刺尾鱼,（学名：Acanthurus bahianus）是刺尾鲷科、刺尾鱼属海水鱼类。长度约为30.5厘米。在南美洲海岸附近捕获的最大标本，37厘米。嘴中有紧密的具小齿边的匙形牙齿。椭圆形身体中等深度且受压。嘴小而头部低，非常适合从岩石和珊瑚上刮除藻类。尾柄的侧面有一个像手术刀一样锋利的脊椎。相对较长的背鳍是连续且无缺口的。尾鳍中度至重度萎缩。鳞片小且呈类软骨状。身体呈淡黄色至灰褐色，并带有淡绿色的灰色至淡蓝色的垂直线。背鳍边缘为蓝色、橙色和蓝绿色交替排列。肛门鳍的颜色类似，但很少有明显的带状物。尾鳍为橄榄色至棕色。尾椎的窝处有一个小的紫色或蓝色区域。在产卵期间以及种内竞争和其他交流过程中可能会发生颜色变化。

百度翻译提供：

The moon tail Barbus (scientific name: Acanthurus bahianus) is a marine fish of the family Sparus and the genus Barbus. The length is about 30.5 cm. The largest specimen captured near the coast of South America, 37 cm. There are dense spoon shaped teeth with small teeth in the mouth. The oval body is moderately deep and compressed. With a small mouth and low head, it is very suitable for scraping algae from rocks and corals. There is a spine as sharp as a scalpel on the side of the tail handle. The relatively long dorsal fin is continuous and uncut. Moderate to severe atrophy of caudal fin. The scales are small and cartilage like. The body is light yellow to grayish brown, with light green gray to light blue vertical lines. The edges of dorsal fins are alternately arranged in blue, orange and blue-green. The color of anal fins is similar, but there are few obvious bands. The caudal fin is olive to brown. There is a small purple or blue area in the fossa of the caudal vertebra. Color changes may occur during spawning and during intraspecific competition and other communication.

栖息在由珊瑚和岩石构成的浅水底部；通常以5个个体的小团体或更多个体的团体的形式出现；属于白天觅食的种类，经常与其他物种（包括蓝塘和刺尾鱼）一起出动。主要食用生长在珊瑚上的藻类。分布于巴西（特林达德、圣卡塔琳娜州、费尔南多·迪诺罗尼亚群岛）、圣海伦娜（阿松森岛）和特里斯坦达库尼亚。