Yellowfin Surgeonfish Identification Guide

Key identification features

• Large, deep-bodied surgeonfish reaching up to 60 cm, among the biggest Acanthurus species
• Grey-brown to purplish-grey body color that can darken or pale depending on mood
• Bright yellow pectoral fins that contrast sharply with the body
• Fine blue wavy lines radiating outward from the eye across the cheek
• Orange-yellow ring encircling the white caudal spine
• Large, rounded head profile compared to smaller reef-dwelling relatives

Common look-alikes

Ringtail surgeonfish is similar in overall shape but shows a pale ring around the tail base rather than yellow pectoral fins. Elongate surgeonfish is close in size and color but has a noticeably more elongated body and plain, not yellow, pectoral fins. Both lack the strong yellow flash at the pectoral fins that immediately marks a yellowfin surgeonfish.

Where you'll see one

Yellowfin surgeonfish are widespread across the Indo-Pacific, usually found over sand patches, lagoon floors, and rubble adjacent to reefs, often solitary or in loose, spread-out groups rather than tight schools, particularly around channel edges.