THE ANIMAL FILES

Atlantic mackerel

Scomber scombrus

A mackerel school can change formation when the prey changes.

Atlantic mackerel are streamlined schooling fish of the North Atlantic and neighbouring seas. A blue patterned back, pale sides and small finlets mark their outline. Their feeding and movement link plankton-sized prey to fish that travel between coastal and more offshore waters.[1]

Follow the evidence ↓
Atlantic mackerel
Image: Hans Hillewaert · Commons · CC BY-SA 4.0
Body
Fusiform with a narrow tail base[1]
Foods
Copepods and other prey[1]
Young
Early larvae drift with currents[1]

Small fins behind the big ones

The main dorsal and anal fins are followed by small finlets toward the tail. The body narrows into a slim caudal peduncle supporting a broad tail fin. Dark wavy lines cross the steel-blue back, while the lower body is pale. These features help distinguish the fish without relying on its maximum size.[1]

A school shaped by food

When taking plankton, fish can pack closely and swim with mouths open, making escape from one mouth lead toward another. Copepods are important food. With larger prey, schools tend to loosen into shoals and individuals feed more independently. The same species therefore need not keep one fixed spacing in every feeding situation.[1]

From drifting larvae to schooling fish

Released eggs are pelagic, and hatching time depends on water temperature. Newly hatched larvae initially use their yolk supply, then feed and grow through later stages. Early larvae have little swimming ability and drift with currents. Schooling appears as juveniles develop an adult-like form, connecting a mobile adult life to a less self-directed beginning.[1]

A COMMON MIX-UP

Does every mackerel life stage swim in an organised school?

No. Early larvae drift; schooling appears later as juveniles develop.[1]

TRY A LITTLE REASONING

Why might tightly packed open mouths help catch tiny drifting prey?

Reveal the explanation

A prey item escaping one fish can enter the path of its neighbour, reducing clear escape space.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Scomber scombrus (adapted and translated; exact revision)
  2. NCBI Taxonomy — Scomber scombrus (identity and game lineage)

Last fact check:

One discovery leads to another

Blue mackerelA streamlined hunter with a surprisingly broad small-prey menu.Scomber australasicus ↗Yellowfin tunaBright yellow fins mark a predator that can also become prey.Thunnus albacares ↗Allmouth goosefishThe fishing rod is part of the fish.Lophius piscatorius ↗