Alex Mustard / Bengal snapper (Lutjanus bengalensis), Bannerfish (Heniochus diphreutes) and Fusiliers (Caesio sp.) diving towards coral reef to avoid predators. North Ari Atoll, Maldives. Indian Ocean.

Jordi Chias / Schoolmaster snapper (Lutjanus apodus) school in the reef, Little Cayman island, Cayman Islands, Caribbean.

Tony Wu / Twinspot snapper (Lutjanus bohar) engaged in a mass spawning aggregation early in the morning. Caroline Islands, Palau. April.

Tony Wu / Twinspot snapper (Lutjanus bohar) shoal rushing up to spawn, releasing a cloud of milky white sperm and eggs in the water column. Caroline Islands, Palau, November.

Doug Perrine / Barjacks (Caranx ruber), Yellowtail snapper (Ocyurus chrysurus), and Sergeant major damselfish (Abudefduf saxatilis) swimming around wreck of bow gun on C-58 shipwreck off Puerto Morelos, near Cancun,...

Alex Mustard / Portrait of pair of Bohar snappers (Lutjanus bohar) in their spawning aggregation. Shark Reef, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Alex Mustard / Portrait of Bohar snappers (Lutjanus bohar) in its spawning aggregation. Shark Reef, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea.

Hiroya Minakuchi / Atlantic Spotted Dolphin (Stenella frontalis) trio predating on school of snappers, Bahamas, Caribbean

Hiroya Minakuchi / Atlantic Spotted Dolphin (Stenella frontalis) chasing school of snappers, Bahamas, Caribbean

Hiroya Minakuchi / Atlantic Spotted Dolphin (Stenella frontalis) feeding on school of snappers, Bahamas, Caribbean

Georgette Douwma / Schooling Pinjalo snapper (Pinjalo lewis). West Papua, Indonesia. Indo-West Pacific.

Nick Hawkins / Blue-lined snapper (Lutjanus kasmira) shoal. Cocos Island National Park, Costa Rica.

Nick Hawkins / Blue-lined snapper (Lutjanus kasmira) shoal. Near Cocos Island National Park, Costa Rica.

David Fleetham / Bluestripe snapper (Lutjanus kasmira) school under rock arch, introduced species. Kona Coast, The Big Island, Hawaii.

David Fleetham / Blacktail snapper (Lutjanus fulvus) in coral reef. Kauai, Hawaii.

Georgette Douwma / RF - Shoal of Slender pinjalo snappers (Pinjalo lewisi) swimming over soft corals on coral reef. West Papua, Indonesia. (This image may be licensed either as rights managed or royalty free.)

Georgette Douwma / RF - Kasmira snappers (Lutjanus kasmira) over coral reef. Triton Bay, West Papua, Indonesia. (This image may be licensed either as rights managed or royalty free.)

Georgette Douwma / Bigeye snapper (Lutjanus lutjanus) school over coral reef. Triton Bay, West Papua, Indonesia.

Alex Mustard / RF - Hawksbill turtle (Eretmochelys imbricata) on coral reef, with Bengal snapper fish (Lutjanus bengalensis) in background. North Ari Atoll, Maldives. Indian Ocean. (This image may be licensed either...

Alex Mustard / Blueline snapper (Lutjanus kasmira) school. Vavuu Atoll, Maldives. Indian Ocean.

Alex Mustard / RF - Blueline snapper (Lutjanus kasmira) school. Vavuu Atoll, Maldives. Indian Ocean. (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / Blueline snapper (Lutjanus kasmira) school above Black coral (Antipatharia) in reef. Vavuu Atoll, Maldives. Indian Ocean.

Alex Mustard / Blueline snapper (Lutjanus kasmira) school. Vavuu Atoll, Maldives. Indian Ocean.

Alex Mustard / Schoolmaster snapper (Lutjanus apodus) on coral reef. East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Claudio Contreras / Elkhorn coral (Acropora palmata) French Grunt (Haemulon flavolineatum) and Schoolmaster Snapper (Lutjanus apodus), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Av...

Linda Pitkin / Mahogany snapper (Lutjanus mahogoni), above coral reef, Bonaire, Leeward Antilles, Caribbean.

Linda Pitkin / Schoolmaster snapper (Lutjanus apodus) on coral reef Bonaire, Leeward Antilles, Caribbean.

Linda Pitkin / Schoolmaster snapper (Lutjanus apodus) on coral reef Bonaire, Leeward Antilles, Caribbean.

Linda Pitkin / Mahogany snapper (Lutjanus mahogoni) aggregation Bonaire, Leeward Antilles, Caribbean.

Georgette Douwma / Two-spot banded snapper (Lutjanus biguttus). Malaysia.

Georgette Douwma / Two-spot banded snapper (Lutjanus biguttus). Malaysia.

Jordi Chias / Lunar-tailed bigeye (Priacanthus hamrur) with blueline snappers (Lutjanus kasmira) in the background;Mozambique

Jordi Chias / School blueline snappers (Lutjanus kasmira) South Ari Atoll, Maldives, Indian Ocean.

Jordi Chias / Potato cod (Epinephelus tukula) with school Blueline snappers (Lutjanus kasmira) Tofo Coast, Mozambique, Indian Ocean. South-East Coast.

Linda Pitkin / Slender pinjalo (Pinjalo lewisi) fish schooling, Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Slender Pinjalo (Pinjalo lewisi) fish schooling, Triton Bay, near Kaimana, West Papua, Indonesia, February 2017

Linda Pitkin / Bigeye snappers (Lutjanus lutjanus) schooling in coral reef gully, Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Two-spot banded snapper (Lutjanus biguttatus), Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Slender pinjalo (Pinjalo lewisi) fish schooling, Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Slender pinjalo (Pinjalo lewisi) fish schooling, Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Slender pinjalo (Pinjalo lewisi) fish schooling, Triton Bay, near Kaimana, West Papua, Indonesia

Alex Mustard / School of Bohar snapper (Lutjanus bohar) swimming in formation along a coral reef. These fish are usually solitary and aggregate each summer in the Red Sea to spawn. Ras Mohammed National Park, Sinai...

Alex Mustard / Blackspot snapper (Lutjanus ehrenbergii). Beacon Rock, Sinai, Egypt. Red Sea.

Alex Mustard / Large group of Midnight snappers (Macolor macularis) race in to feed on eggs spawned by bohar snappers. Ulong, Rock Islands, Palau, Mirconesia. Tropical west Pacific Ocean

Alex Mustard / Schoolmaster snapper (Lutjanus apodus) hunts silversides (Atherinidae) inside a coral cavern. George Town, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Alex Mustard / School of Bohar snapper (Lutjanus bohar) in open water above a coral reef. These fish are usually solitary and aggregate each summer in the Red Sea to spawn. Shark Reef, Ras Mohammed, Sinai, Egypt. Re...

Alex Mustard / School of Bohar snapper (Lutjanus bohar) in open water close to a coral reef. These fish are usually solitary and aggregate each summer in the Red Sea to spawn. Shark Reef, Ras Mohammed, Sinai, Egypt....

Alex Mustard / School of Bohar snapper (Lutjanus bohar) in open water close to a coral reef. Shark Reef, Ras Mohammed, Sinai, Egypt. Red Sea.