Scomber

[…] the familiar name by which all scombers are known at Montpelier being the peis d’avril, or April fish. […] All times and tongues have agreed to call the first of these scombers by some name allusive to the warlike weapon carried in his mouth—viz., a sword, several feet in length, finely attenuated in front, and, to the dismay of the denizens of the deep, of a temper like that of its owner, not to be trusted or trifled with. […] The size and strength of these fish are as remarkable as their pugnacity; the power, as in most scombers, residing in the muscles moving the tail.

Source: wiktionary

[…] large carongues and scombers are found in the Canarian seas, and the similarity of several species is most remarkable.

Source: wiktionary

All of the Scombers are of the most highly organized order of fishes, most. of them being without air-bladders, being so adapted to their native element that they have no need of them.

Source: wiktionary

The tail with its caudal fin, set vertically, is able to effect a rapid burst of speed which allows the fish to make a dash after its prey, but it cannot keep up this speed for long. At the rear it acts as a scull, beating the water first to right and then to left, and so pushing the body forward. Only some sharks and the large mackerel or scombers are capable of using this tool with an effect comparable to that attained by the cetaceans. […] The whole construction of these large scombers is designed to make of them, like fast ships, the greyhounds of the sea. […] The case of the tunny and the large scombers, whose massive bodies become considerably warmer when they are swimming, is an exception.

Source: wiktionary