Aspect: White-silvery body with light marked mid-body horizontal lines, and four heavy black vertical bars - one running across the eyes, two larger ones mid-body and a fourth running through the base of the tail. Upper snout area also features a blue and yellow moiré pattern. Population: Regularly abundant. Notable feature: Tail, together with the dorsal and anal fins are black but contoured with a thinner white line, itself finishing with a transucent membrane. Environment: Usually found in relatively shallow, quiet waters, nibbling at algae on rocks and boulders. Behaviour: Will remain quiet if approached smoothly, particularly when busy feeding.