David Fleetham / Cleaner wrasse (Labroides dimidiatus) swimming alongside Golden damsel (Amblyglyphidodon aureus) looking for parasites, Fiji, Pacific Ocean.

Alex Mustard / Portrait of Blacktip grouper (Epinephelus fasciatus) resting in Barrel sponge (Xestospongia testudinaria) Mabul Island, Sabah, Borneo, Malaysia. Sulawesi Sea.

Franco Banfi / Golden grouper (Mycteroperca rosacea), yellow color-variation of the most common leopard grouper species, Cabo Pulmo Marine National Park, Baja California Sur, Mexico

Franco Banfi / Golden grouper (Mycteroperca rosacea), yellow color-variation of the most common leopard grouper species, Cabo Pulmo Marine National Park, Baja California Sur, Mexico

Alex Mustard / Coral grouper (Cephalopholis miniata) waits in ambush, hiding against a seafan (Annella sp.) hunting silversides (Atherinidae), with schooling bigeye snapper (Lutjanus lutjanus) behind. Misool, Raja A...

Georgette Douwma / Blacktip grouper (Epinephelus fasciatus) Egypt, Red Sea.

Georgette Douwma / Coral reef scenery with soft corals (Dendronephthya sp), a Coral hind (Cephalopholus miniata) and Pygmy sweepers (Parapriacanthus guentheri) Egypt, Red Sea.

Tim Laman / Coral reef with school of Golden Sweepers (Parapriacanthus ransonneti), barrel sponge, and Sixspot Grouper (Cephalopholis sexmaculata), Indo Pacific

Franco Banfi / Goldblotch grouper (Epinephelus costae), inside a wreck, Ponza Island, Italy, Tyrrhenian Sea, Mediterranean.

Shane Gross / Masked butterflyfish (Chaetodon semilarvatus) pair and Coral hind (Cephalopholis miniata) in coral reef. Marsa Alam, Egypt.