On mackerel in tomato sauce Wikipedia the language links are at the top of the page across from the article title. This article is about the species of fish.

For its use as food, see Mackerel as food. Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment. Mackerel species typically have deeply forked tails and vertical ‘tiger-like’ stripes on their backs with an iridescent green-blue quality. Smaller mackerel are forage fish for larger predators, including larger mackerel and Atlantic cod. Over 30 different species, principally belonging to the family Scombridae, are commonly referred to as mackerel. The term “mackerel” is derived from Old French and may have originally meant either “marked, spotted” or “pimp, procurer”.

About 21 species in the family Scombridae are commonly called mackerel. The type species for the scombroid mackerel is the Atlantic mackerel, Scomber scombrus. The true mackerels belong to the tribe Scombrini. The Spanish mackerels belong to the tribe Scomberomorini, which is the “cousin tribe” of the true mackerels. In addition, a number of species with mackerel-like characteristics in the families Carangidae, Hexagrammidae and Gempylidae are commonly referred to as mackerel.

By extension, the term is applied also to other species such as the mackerel tabby cat, and to inanimate objects such as the altocumulus mackerel sky cloud formation. Like other scombroids, mackerel such as this Atlantic mackerel are superb swimmers, and can retract their fins into grooves on their bodies for streamlining. They have deeply forked tails and are smaller and slimmer than tuna. Most mackerel belong to the family Scombridae, which also includes tuna and bonito. Generally, mackerel are much smaller and slimmer than tuna, though in other respects, they share many common characteristics. Their scales, if present at all, are extremely small.

The type species for scombroid mackerels is the Atlantic mackerel, Scomber scombrus. These fish are iridescent blue-green above with a silvery underbelly and near-vertical wavy black stripes running along their upper bodies. The prominent stripes on the back of mackerels seemingly are there to provide camouflage against broken backgrounds. That is not the case, though, because mackerel live in midwater pelagic environments which have no background.