Blue knifefish

The blue knifefish (Labracoglossa nitida) is a species of marine ray-finned fish, a member of the subfamily Scorpidinae of the sea chub family Kyphosidae. It is native to the Pacific Ocean waters off eastern Australia over to New Zealand, where it occurs at depths reaching from the surface to 20 m in inshore waters over reefs. It can reach a length of 20 cm, though most do not exceed 15 cm.