Mackerel, a well known acanthopterygian fish of the scomberoid family, and one of great utility to man, from its countless numbers and excellence as food. This family includes also the bonito and its allied forms, the tunny, the pilot fish, and the sword fish. The scales are small, delicate, and smooth, the bones light, the tail slender, and gill covers unarmed; the first dorsal fin continuous, the rays of the second and of the anal detached, forming finlets, and with a large interval between the dorsals; the body is fusiform, the caudal fin powerful, the tail usually with a slight keel on the side, the vertical fins without scales; a row of small conical teeth in each jaw; branchiostegal rays seven; most of the species have no air bladder. The common European mackerel (scomber scombrus, Cuv.), so well known for the beauty and brilliancy of its colors and the elegance of its form, has a pointed nose, the under jaw the longer, the gill covers large and smooth, the pectorals and ventrals in advance of the dorsal, the former the most anterior, five finlets above and below the tail, vertically over each other, and the tail crescent-shaped; the color above the lateral line is fine green varied with blue, and marked with broad, descending, undulating, dark lines; the lower parts are silvery with golden tints.

According to Anderson, the mackerel performs migrations almost as extensive as the herring; it probably inhabits almost every part of the European seas, and comes into shallow water at particular seasons to breed; were it not for these periodical visits, no effective fishery could be carried on, as it would be impracticable to follow the shoals over the ocean; great as is the number caught, it is very small compared with those which escape. It is caught on the shores of Great Britain from March to June, spawning in the latter month; the young, called shiners, are 6 in. long by the end of August; in winter they retire to deep water, though a few are taken on the Cornish coast all the year round; as many as 500,000 eggs have been counted in a single female. The mackerel is very voracious, feeding principally on the fry of other fish; it grows rapidly, and attains an average length of 15 in., and a weight of 2 lbs., though some considerably exceed this. It is considered better in May or June than earlier or later in the season; the flesh rapidly becomes soft, and must be eaten soon after being taken from the water; much of the flavor, however, is retained in the salted fish.

The mackerel season is a very busy and profitable one on the British coasts, a single boat's crew sometimes gaining £100 in a night's fishing. They are taken in large quantities by drift nets, reaching about 20 ft. below the surface, and extending for more than a mile; these are set in the evening, and the fish, roaming at night, are caught in the meshes and retained by the pectoral fins; they are caught also in seines and by trailing. The mackerel will bite at almost any bait, especially anything resembling a living prey, and will even dart at a piece of red cloth or leather; it generally takes the hook not far below the surface. The Spanish mackerel (S. colias, Gmel.), found abundantly in the Mediterranean, occasionally upon the French and English coasts, and perhaps even in American waters (though a different species from that commonly known here by that name), is about as large as the last, with larger scales, and with the dark undulations of the back more complicated and the whole surface more or less spotted with gray; it has an air bladder, which the common species has not; it is far inferior also as an article of food.

Mackerel of these and many other species, described in ichthyological works, are found in all the northern seas from Greenland to the Mediterranean, in the Black sea and that of Azov, and in the waters of Australia, the East Indies, the Cape of Good Hope, the North Atlantic, and the American coasts; they have everywhere, and from remote antiquity, maintained a high rank as an article of food. Not only man, but many species of cetaceans and fish, prey upon the mackerel; among their greatest enemies in our waters are the horse mackerel or tunny and the blue fish. From the perishable nature of their flesh, it is permitted in many English seaports to cry them in the streets on Sundays. - The common mackerel of our coast is the S. rer-nalis (Mitch.), of a dark green color above, with beautiful undulations of a darker color extending below the lateral line; the top of the head is dark, almost black, and a large black blotch extends backward from the occiput to the gill covers; behind the eyes cupreous; gill Covers silvery, sides white with cupreous reflections, and abdomen white; beneath the lateral line is a fuliginous line, often interrupted, extending the whole length of the fish.

The fins and finlets are much like those of the European species. - Mackerel fishing is carried on extensively in Massachusetts and Maine, the principal ports being Provincetown, Wellfleet, Harwich, Dennis, Cohasset, Boston, Salem, and Gloucester in the former state, and Portland, Southport, Boothbay, Camden, North Haven, and Deer Isle in the latter. The vessels employed are schooners of from 45 to 90 tons, averaging about 65 tons, and carrying an average of 15 men when the fish are taken with the seine, or 17 men when the hook and line are used. The seine, which is now used by most vessels except in the gulf of St. Lawrence, did not come into general use till 1873. The seines weigh about 2,000 lbs. each, and are 175 fathoms long by 24 fathoms in width or depth in the middle, the depth gradually diminishing to 11 fathoms at the ends. Corks are placed a few feet apart along the upper rope, while rings, through which a rope called the " purse line " passes, are attached to the lower. A boat about 30 ft. long, manned by 10 men, with 8 oars including the steering oar, is carried for casting the seine. Two dories, about 13 ft. in length, manned by one or two men each, are employed to assist the seine boat.

The fish are usually seen in shoals just rippling the surface of the water, moving slowly in one direction, frequently to windward. In casting the seine the boat takes a position 15 or 20 yards to the left of the head of the shoal, the ends of the cork rope and purse line are given to the dory, and the seine is thrown out as the boat is rowed in a circuit to the right until the dory, which has been lying still, is reached again. Then the cork rope and purse line are taken by the boat, and the seine is drawn or " pursed " up, enclosing the fish. The vessel is next brought alongside, and the fish are taken from the seine in dip nets. The process of seining under favorable circumstances is simple and easy, but with high winds it becomes difficult or impossible. The fish sometimes when surrounded dive, and passing under the seine elude the fishermen; at other times they fail to shoal for days together. They may sometimes be kept on the surface until the seine is cast around them by throwing bait from the vessel. The experienced fisherman, when a choice is offered him, does not select the largest shoal, from 200 to 250 barrels being as many as can be taken care of at a time. An unsuccessful cast of the seine consumes about two hours.

In the gulf of St. Lawrence, the habits of the mackerel being less favorable for seining and high winds being more prevalent in the latter part of the season, the old method of fishing with hook and line still prevails. When this method is employed, each man has a space or berth assigned him of about 30 inches on the starboard rail of the vessel, and is provided with four or six lines of about seven fathoms in length, with " jigs " made by running sufficient pewter on the shank of the hook to cause it to sink readily. The jigs are baited with small pieces of the skin of the mackerel. When about to make a trial the vessel is hove to on the starboard tack, and thus lies drifting moderately to leeward. Bait is then thrown to entice the mackerel to the surface, or "raise " them as it is termed, and to keep them alongside. The bait consists chiefly of porgies, though clams are sometimes used, and is ground in a bait mill, and thrown from boxes hung over the side of the vessel. The average quantity of bait used during the season by each vessel is 80 barrels, though when the fish are taken with the seine not more than 25 barrels are required. If the mackerel are successfully raised and bite well, three hours suffice to secure 100 barrels.

Vessels of the average size have capacity for 250 or 300 barrels, and usually prepare for a trip of four or five weeks. - The process of dressing mackerel consists of four distinct operations, splitting, gipping, ploughing, and salting. The splitter splits the fish at the rate of 1,500 per hour, the knife passing along the back from the head to the tail, leaving the back bone on the right side, and throws them into a tub. Two gip-pers stand at each tub, remove the gills and entrails, and pass the fish into a barrel, called the "wash" barrel, where they are allowed to soak. Subsequently they are taken out singly, laid on a board skin down, and a light stroke of the plough, which consists of a piece of knife blade or similar instrument, is given on each side of the fish from the head two thirds down to the tail. When the fish are taken rapidly, however, this operation (which is designed to give the fish an appearance of fatness) is sometimes postponed until after they are landed. The last operation, salting, is performed by laying the fish singly in a barrel and sprinkling a light handful of salt on each. They are then allowed to remain over night, when some of the pickle is drained off, and the barrels are filled, headed up, and stowed below.

A little less than a bushel of salt is used for a barrel, and it requires five wash barrels to make four barrels of salted fish. After being landed the mackerel are assorted, inspected, and branded by a state officer appointed for the purpose, and repacked for market. The size and quality are denoted by the numbers 1, 2, 3, and 4. No. 1 mackerel must be 13 in. long; No. 2, 11 in. To rate as No. 1 or No. 2 they must also be fat and in good condition. When of inferior quality and 13 in. in length, they are branded as No. 3 large; between 10 and 13 in., No. 3. All other mackerel free from taint or damage are rated No. 4. The first cargoes landed are invariably poor, and usually of good size. As the season advances the mackerel improve in condition, and after the beginning of July they are usually fat enough to pack according to size. The method of employing the crew in general use is known as the "half-line lay." By this method the crew draw one half of the gross stock, out of which they pay the cook's wages, one half of the bait bill, and one half of the expense of packing, realizing about 40 per cent. net. When the hook and line are used, the fish caught by each man are kept separate, and the voyage is settled individually.

In the cases of seiners the voyage is simply divided into shares for the men and parts of shares for the boys. The manager or "boss" of the seine generally receives from $50 to $100 extra from the owners, who also pay the captain a commission (usually about 4 per cent.) on the gross stock. The price of mackerel in the market, particularly the better qualities, is subject to great fluctuations. The average earnings of a fisherman employed through the season may be stated at $300. The season begins about the first of April, and the fleet gradually increases until July, the greatest number of vessels being employed from that time to the early part of November, when the season closes. The early fleet, from 25 to 50 sail, first find the mackerel as far S. as Cape Henry and about 50 m. from land. For the first two months they ice the fish as soon as caught, and bring them fresh to the New York market; after that they carry salt and barrels and cure the fish. As the season advances the mackerel move N., the distance from the shore varying with the wind, being less with a W. than an E. wind; and from about the first of May to the latter part of June they are found from Cape May to Gay Head. About the first of July they move E. around the S. side of Nantucket, and from then until September they may be caught anywhere from that island to Cape Sable. During July and August many of the vessels cruise on George's bank; after the first of September the fleet is scattered from the Maine coast around the shore to Chatham, the last catch being usually off that port.

A small fleet of "market boats," from 30 to 50 tons each, from Boston, Swampscott, and Duxbury, supply the Boston market with fresh fish, making their first trip about the middle of May, when mackerel first appear in Boston bay, and continuing until the last of November. In June a number of vessels, principally from Gloucester, Maine, and Nova Scotia, proceed to the gulf of St. Lawrence, and pursue the fishery chiefly around the shores of Prince Edward island and the Magdalen islands. This fleet increases during July and August, and is largest from that time until the last of October, when the season closes. The importance of the gulf fishery in comparison with the shore fishery, as that along the Atlantic coast is termed, has recently diminished. The number of barrels of mackerel inspected in the United States in 1873 was as follows:

Common Mackerel (Scomber vernalis).

There were 1,261 barrels reinspected in Maine and 37,388 in Massachusetts; total, 38,649. The Canadian catch for the year ending June 30, 1873, was 150,404 barrels, viz.: Quebec, 6,170; New Brunswick, 3,229; Nova Scotia, 141,005; besides 31,892 cans of preserved fish. (See. Fisheries.) - The fish called Spanish mackerel on our coast, S. Dekayi (Storer), much resembles the European S. colias (Gmel.), but is more robust, with more numerous spots, and with an interrupted dull brown band beneath the lateral line, extending from beneath' the pectorals in a straight line to the tail. It is far less common than the S. vernalis; it is generally fat, and is regarded by epicures as a superior fish for the table. Another scom-beroid, belonging to the genus cybium of Cuvier (C. maculatum, Cuv.), is also called the Spanish or spotted mackerel; the body is elongated, but without the pectoral corslet of the tunny; there is an elevated crest on each side of the tail, and a smaller one above and below it; the teeth are large, compressed, and sharp, short, and even on the palate bones.

The length is about 20 in.; the color above is dark leaden, lighter on the sides; the jaws, gill covers, and abdomen clear white, with a satin lustre; the dorsal ridge dark green; 20 or more circular or oblong spots on the sides above and below the lateral line, most of them above the line and anterior to the second dorsal; the membrane of the first dorsal black, the second leaden, pectorals black below and light above, and the ventrals white; the rays of the first dorsal project beyond the membrane; the second dorsal is triangular, emarginated behind; there are eight or nine finlets between the caudal and the second dorsal and the anal. It extends from South America as far as the coast of Maine, and is esteemed as food.

Spotted Mackerel (Cybium maculatum).