mackerel Scomber scombrus, a common fish of N. Atlantic and Mediterranean waters. With its brilliant greeny-blue back marked with dark curving lines, its metallic sides, and white belly, it is a handsome fish. One might almost describe it as flashy in appearance, noting that the French name maquereau also means pimp and that in the past mackerel was a term for dandy in England.
Mackerel are oceanic fish, which normally swim in very large shoals. Their range extends from the Black Sea and the Mediterranean to Norway and Iceland; and from Labrador on the American side down to Cape Hatteras. Their maximum length is 55 cm (22") or a little more, but the common market length is around 30 cm (12").