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
Chilean jack mackerel for Pacific jack mackerel. The Chilean jack mackerel looks very much like the greenback horse mackerel "(Trachurus declivis)" found around Australia and New Zealand. The two species can be distinguished by the number of gill rakers ("T. declivis" 50–57, "T. murphyi" 51–65) and the number of scales and scutes in the lateral line ("T. declivis" 81–82, "T. murphyi" 89–113). All three species are found schooling around the coast of New Zealand. They are mainly captured using purse seine nets, and are managed as though they were one species or stock. Chilean jack mackerel The Chilean jack mackerel ("Trachurus murphyi") sometimes