Pascal Kobeh / Bluestreak cleaner wrasse (Labroides dimidiatus) cleaning Spotted unicornfish (Naso brevirostris) Palau. Philippine Sea.

Alex Mustard / School of Bluespine unicornfish (Naso unicornis) gathered during the summer breeding season. Yolanda Reef, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Alex Mustard / Herbivorous blue tang (Acanthurus coeruleus) swimming through the rigid branches of a pillar coral (Dendrogyra cylindrus) East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Pete Oxford / Blue tang (Acanthurus coeruleus) Bonaire, Netherlands Antilles, Caribbean

Pete Oxford / Blue tang (Acanthurus coeruleus) Coral Reef Island, Belize Barrier Reef, Belize

Pete Oxford / Blue Tang Surgeonfish (Acanthurus coeruleuss), Belize Barrier Reef, Belize

GEORGETTE DOUWMA / Yellowtail tang / surgeonfish (Zebrasoma xanthururm). Red Sea, Egypt

Michael Pitts / Blue Tang (Acanthurus coeruleus) grazing on hull of the wreck of the ''Blue Plunder'', Bahamas. August 2008.

Doug Perrine / Blue tang {Acanthurus coeruleus} feeding on Thimble jellyfish {Linuche unguiculata} Cayman Islands, Caribbean

Norbert Wu / Blue Tang (Paracanthurus hepatus), Indo-Pacific

Fred Bavendam / Powderblue Surgeonfish (Acanthurus leucosternon), Andaman Sea, Thailand

Norbert Wu / Blue Tang (Paracanthurus hepatus) portrait, native to Indo-Pacific Ocean region