Tony Wu / Zoarchias major eelpout (Zoarchias major) female attempting to dislodge a male from a hole in the reef. Yamaguchi Prefecture, Japan. Pacific Ocean.

Tony Wu / Two female Zoarchias major eelpouts (Zoarchias major) engaged in a fight. Yamaguchi Prefecture, Japan, Pacific Ocean.

Tony Wu / Two male Zoarchias major eelpouts (Zoarchias major) engaged in a mouth-to-mouth confrontation. Yamaguchi Prefecture, Japan, Pacific Ocean.

Tony Wu / Zoarchias major eelpouts (Zoarchias major) female approaching another one that has occupied a hole in the reef. The aggressor has clamped her mouth on the occupying fish in an attempt to intimidate an...

Alex Mustard / Blue tang (Acanthurus coeruleus) with Bluehead (Thalassoma bifasciatum) juveniles at cleaning station on coral reef. George Town, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea. Digi...

Linda Pitkin / Blue tang (Acanthurus coeruleus) and Doctorfish (Acanthurus chirurgus), in foraging aggregation. Bonaire, Leeward Antilles, Caribbean.

Linda Pitkin / Scrawled filefish (Aluterus scriptus) shadowed by Trumpetfish (Aulostomus maculatus). Blue Tang (Acanthurus coeruleus) also in this mixed fish species feeding association. Bonaire, Leeward Antilles,...

Alex Mustard / Portrait of a Blackbar soldierfish (Myripristis jacobus) infected with Cymothoid isopod parasites. The large parasite between the eyes is a female, the smaller individuals are males. Seven Mile Beach,...

SCOTLAND: The Big Picture / European river otter (Lutra lutra) feeding on eelpout, Shetland, Scotland, UK, August.

Pascal Kobeh / Spanish hogfish (Bodianus rufus) is cleaning a Blue tang surgeonfish (Acanthurus coeruleus) Yucatan Peninsula, Mexico

Claudio Contreras / Blue tang (Acanthurus coeruleus) Yalku inlet, Caribbean Sea, Mexico, February

Claudio Contreras / Blue tang (Acanthurus coeruleus) Yalku inlet, Caribbean Sea, Mexico, February.