This is larva of Zanclus cornutus (Linnaeus, 1758). Total length about 50mm. I still have never encountered any more small size. They usually appear near the surface of water. The body is semi-transparent, it has appeared faintly black pattern. 3rd spine of dorsal fin is extended. Perceptible bumps of located above adult eye does not exist. Larva of Zanclus cornutus (Linnaeus, 1758) TL:50mm Larva of Zanclus cornutus (Linnaeus, 1758) TL:50mm REFERENCES: Nakabo, T. (ed.), 2013. Fishes of Japan with pictorial keys to the species, third edition. Tokai University Press, Kanagawa, Pp, 2428. (3-Volume Set) (in Japanese). Okiyama M. (ed), 2014. An Atlas of Early Stage Fishes in Japan Second Edition Tokai University Press, Japan. :Pp,1912. (in Japanese).