Also known as Blackbelly Triplefin, Greentail Triplefin, Halfback Threefin, Halfblack Threefin, Threefin, Threefin Blenny.
Found singly or in pairs on coral and rocks of reef flats, surf swept reef margins and in tide-pools.
They feed on benthic invertebrates.
Length - 4.8cm
Depth - 0-30m
Widespread Western Pacific
These Blenny related fish have three fins which gives them the their name "Triplefins" Ref: https://www.fishbase.se/summary/14196