Mackerel fish, sometimes indicating the fish has vertical stripes similar to a scombroid 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. 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. Like tuna and bonito, mackerel are voracious feeders, and are swift and manoeuvrable swimmers, able to streamline themselves by
Mackerel 21 species in all—18 of those are classified into the genus "Scomberomorus", two into "Grammatorcynus", and a single species into the monotypic genus "Acanthocybium". In addition, a number of species with mackerel-like characteristics in the families Carangidae, Hexagrammidae and Gempylidae are commonly referred to as mackerel. There has been some confusion between the Pacific jack mackerel ("Trachurus symmetricus") and the heavily harvested Chilean jack mackerel ("Trachurus murphyi"). These have been thought at times to be the same species, but are now recognised as separate species. The term "mackerel" is also used as a modifier in the common names of other