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.

Todd Mintz / Bar Jack (Caranx ruber) predating on dense school of Scad fish / Horse mackerel (Trachurus trachurus) Bonaire, Dutch Caribbean.

Todd Mintz / Bar Jack (Caranx ruber) predatingdense school of Scad fish / Horse mackerel (Trachurus trachurus) Bonaire, Dutch Caribbean.

Todd Mintz / Bar Jack (Caranx ruber) predating dense school of Scad fish / Horse mackerel (Trachurus trachurus) Bonaire, Dutch Caribbean.

Norbert Wu / Pacific Jack Mackerel (Trachurus symmetricus) school, Guadalupe Island, Mexico

Norbert Wu / Pacific Jack Mackerel (Trachurus symmetricus) school, Guadalupe Island, Mexico

Doug Perrine / Bait ball of Blue jack mackerel / Scad {Trachurus picturatus} Azores, N Atlantic

Nature Production / Japanese Jack Mackerel {Trachurus japonicus} Izu, Shizuoka, Japan

Stephane Granzotto / Mackerel scad (Decapterus macarellus) baitball swimming beneath diver. The typical ball formation is due to the presence of predators. La Ventana, Sea of Cortez, Mexico. May.

Stephane Granzotto / Mackerel scad (Decapterus macarellus) shoal swimming around the diver. The fish are seeking protection from the diver, due to the presence of predators. The fish leave the frame. La Ventana, Sea of Co...

Stephane Granzotto / Pacific bonito (Sarda chiliensis lineolata) shoal hunting Mackerel scad (Decapterus macarellus) baitball from below. The baitball is at the surface of the water. La Ventana, Sea of Cortez, Mexico. May...