A Hiwihiwi has a sort of triangular body in cross section. The general outline is not unsimilar but not as deep as a red moki and it is covered in small white spots.
The fish that Hanglar has posted is a red moki, red with darkish vertical bands. In 40 years of fishing around the Wairarapa and Wellington coasts I have caught one (on crayfish bait). They are very territorial and stick to their reefy area, very seldom caught on a line but are easy prey for skin divers and easily wiped out in a particular area.