Fig. 53. Top: Surgeonfish, Acanthurus xanthopterin Cuvier and Valenciennes. 

 (Coates) Center: Surgeonfish, Acanthurus bleekeri Giinther. Bottom: Sur- 

 geonfish Naso lititratus (Bloch and Schneider). (Shirao) Three representa- 

 tive species of surgeonfishes. Note the sharp spines near the base of the tail. 

 In the genus, Acanthurus, this spine can be extended, but Naso has spines 

 which arise from plates and these are immovable. Both types can inflict 



serious wounds. 



86 



