Alex Mustard / Striped mackerel (Rastrelliger kanagurta) shoal swimming with open mouths, filtering for zooplankton. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) mouth wide open as it swims through the water, filtering zoopankton with its gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Felis Images / Short fin mako shark (Isurus oxyrinchus) head discarded on ground, fins were dispatched for export and remaining meat cubed for sale locally. Negombo Fish Market, Sri Lanka. 2017. Photo Vydhehi Kadur/...

Stephane Granzotto / Indian mackerel (Rastrelliger kanagurta) Tadjourah Gulf, Republic of Djibouti.

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) shoal swimming with open mouths, filtering for zooplankton. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) with mouths wide open as they swim through the water, filtering zoopankton with their gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) with mouths wide open as they swim through the water, filtering zoopankton with their gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Jeff Rotman / Mackerel shark (Lamna nasus) for sale at the Mumbai Fish Market. Mumbai, India.

Pascal Kobeh / School of Mackerel scads (Decapterus macarellus) swimming over a reef with Maldives anemonefish (Amphiprion nigripes) in Magnificent sea anemones (Heteractis magnifica) Maldives. Indian Ocean.

Pascal Kobeh / School of Mackerel scads (Decapterus macarellus) swimming over reef with Maldives anemonefish (Amphiprion nigripes) in Magnificent sea anemones (Heteractis magnifica) Maldives. Indian Ocean.

Staffan Widstrand / Fish and ice sellers with Barracuda (Acanthocybium solandri) in Pulicat town, Pulicat Lake, Tamil Nadu, India, January 2013.