David Fleetham / Schooling Lemon / Milletseed butterflyfish (Chaetodon miliaris) below kayakers off Maui, Hawaii.

David Fleetham / Schooling Lemon butterflyfish (Chaetodon miliaris) near to surface. Maui, Hawaii.

David Fleetham / Looking upwards to schooling Lemon butterflyfish (Chaetodon miliaris) near to surface. Maui, Hawaii.

Georgette Douwma / Coral reef scenery with a pair of Red Sea raccoon butterflyfish (Chaetodon fasciatus), Pygmy sweepers (Parapriacanthus guentheri) and soft corals (Dendronephthya sp) Egypt, Red Sea.

Claudio Contreras,Claudio Contreras / Long-beaked Coralfish (Chelmon rostratus) eye, Inanuran Island, Danajon Bank, Central Visayas, Philippines, April

Georgette Douwma / Two Golden / Masked butterflyfish, Red Sea, Eygpt

Alex Mustard / Eye of a Masked butterflyfish (Chaetodon semilarvatus). This species is endemic to the Red Sea. Ras Mohammed National Park, Sinai, Egypt. Red Sea

Gary Bell/ Oceanwide / Latticed Butterflyfish (Chaetodon rafflesi), Anilao, Philippines

Richard Robinson / Chaetodon lunula Raccoon Butterflyfish (Chaetodon lunula) at South Minerva Reef / Teleki Tonga, a disputed territory in the South Pacific between Tonga and Fiji.

Linda Pitkin / Eightband butterflyfish (Chaetodon octofasciatus) juvenile, Triton Bay, near Kaimana, West Papua, Indonesia

David Fleetham / Bennett's butterflyfish (Chaetodon bennetti) feeding on coral polyps, Fiji.

David Fleetham / Five images of schooling Raccoon Butterflyfish (Chaetodon lunula) digitally combined for this panorama photograph. Lanai, Hawaii.