Naso tergus is the newest species of surgeonfish which was described from specimens collected around Taiwan. The new Naso species along with Acanthurus nigros are the two latest additions to the family Acanthuridae. However unlike A. nigros which was differentiated based on genetics, Naso tergus was described based on a distinct body shape and morphology.
The Taiwanese Naso tergus is closely related to other unicorn surgeonfish such as Naso hexacanthus and Naso caesius but it is distinguished by a slender head and body, rounded blades on the caudal peduncle and no distinctive markings on the body. The small size of Naso tergus could make it an attractive species of unicorn surgoenfish for aquariums but since the original specimens were captured between 70 and 80 meters (230 and 260 feet), we’re not likely to see these at the LFS anytime soon. Naso tergus is described in the latest issue of The Raffles Journal of Zoology. Image above from Puteaux Plongees.