Flip Nicklin / Two scuba divers swimming through sea cave with schooling Grunts, Cocos Island, Costa Rica

Flip Nicklin / Grunt (Haemulidae) school along coral reef, Cocos Island, Costa Rica

Chris Newbert / Galapagos Shark (Carcharhinus galapagensis) among schooling Black-striped Salema (Xenocys jessiae), Galapagos Islands, Ecuador

Chris Newbert / Galapagos Sea Lion (Zalophus wollebaeki) playing with schooling Black-striped Salema (Xenocys jessiae), 30 feet deep, Galapagos Islands, Ecuador

Chris Newbert / Black-striped Salema (Xenocys jessiae) group schooling, and two Galapagos Sharks (Carcharhinus galapagensis) 50 feet deep, Galapagos Islands, Ecuador

Norbert Wu / Goldman's Sweetlips (Plectorhinchus goldmanni) school, Papua New Guinea

Chris Newbert / Galapagos Sea Lion (Zalophus wollebaeki) playing in a school of Black-striped Salema (Xenocys jessiae) 20 feet deep, Galapagos Islands, Ecuador

Fred Bavendam / Diagonal-banded Sweetlips (Plectorhinchus lineatus) school underwater, Great Barrier Reef, Queensland, Australia

Fred Bavendam / Diagonal-banded Sweetlips (Plectorhinchus lineatus) school, Great Barrier Reef, Queensland, Australia

Fred Bavendam / Diagonal-banded Sweetlips (Plectorhinchus lineatus) school, Loloata Resort, Papua New Guinea

Fred Bavendam / Diagonal-banded Sweetlips (Plectorhinchus lineatus) school, Loloata Resort, Papua New Guinea

Pascal Kobeh / School of white margates or white grunts (Haemulon album) Yucatan peninsula, Mexico.