Pascal Kobeh / Close-up of the head of a Yellowfin surgeonfish (Acanthurus xanthopterus) Maldives, Indian Ocean.

Juergen Freund / Yellowfin surgeonfish (Acanthurus xanthopterus), Great Barrier Reef, Queensland, Australia.

Claudio Contreras / Yellowfin surgeonfish (Acanthurus xanthopterus) with Leopard grouper (Mycteroperca rosacea) in the background, Cabo Pulmo National Park, Sea of Cortez (Gulf of California), Mexico, July

Noemie Stroh / Yellowfin surgeonfish (Acanthurus xanthopterus) aggregation above coral reef. Grey reef shark (Carcharhinus amblyrhynchos) juveniles are patrolling the school. Ohotu reef, North Fakarava, French polyn...

Noemie Stroh / Yellowfin surgeonfish (Acanthurus xanthopterus) aggregation above coral reef. Grey reef shark (Carcharhinus amblyrhynchos) juveniles are patrolling the school. Ohotu reef, North Fakarava, French polyn...

Doug Perrine / Tiger shark (Galeocerdo cuvier) with fish hook in corner of its mouth, swimming across coral reef populated with Racoon butterflyfish (Chaetodon lunula), Threadfin butterflyfish (Chaetodon auriga), Su...

Doug Perrine / Male Pearl wrasse (Anampses cuvier) swimming over rocks with Yellow tang (Zebrasoma flavescens) alongside, Kahaluu Beach Park, South Kona, Hawaii, Pacific Ocean.

David Fleetham / Yellowfin surgeonfish (Acanthurus xanthopterus) female at a cleaning station with endemic Hawaiian cleaner wrasse (Labroides phthirophagus) Hawaii.