CHAPTER XVI

PERCOMORPHI

=SUBORDER Percomorphi, the Mackerels and Perches.=—We may place in a single suborder the various groups of fishes which cluster about the perches, and the mackerels. The group is not easily definable and may contain heterogeneous elements. We may, however, arrange in it, for our present purposes, those spiny-rayed fishes having the ventral fins thoracic, of one spine and five rays (the ventral fin occasionally wanting or defective, having a reduced number of rays), the lower pharyngeal bones separate, the suborbital chain without backward extension or bony stay, the post-temporal normally developed and separate from the cranium, the premaxillary and maxillary distinct, the cranium itself without orbitosphenoid bone, having a structure not greatly unlike that of perch or mackerel, and the back-bone primitively of twenty-four vertebræ, the number increased in arctic, pelagic, or fresh-water offshoots.

The species, comprising the great body of the spiny-rayed forms, group themselves chiefly about two central families, the _Scombridæ_, or mackerels, and the _Serranidæ_, the sea-bass, with their fresh-water allies, the _Percidæ_, or perch.

=The Mackerel Tribe: Scombroidea.=—The two groups of _Percomorphi_, the mackerel-like and the perch-like, admit of no exact definition, as the one fully grades into the other. The mackerel-like forms, or _Scombroidea_, as a whole are defined by their adaptation for swift movement. The profile is sharp anteriorly, the tail slender, with widely forked caudal; the scales are usually small, thin, and smooth, of such a character as not to produce friction in the water.

In general the external surface is smooth, the skeleton light and strong, the muscles firm, and the species are carnivorous and predaceous. But among the multitude of forms are many variations, and some of these will seem to be exceptions to any definition of mackerel-like fishes which could possibly be framed.

The mackerels, or _Scombroidea_, have usually the tail very slender, composed of very strong bones, with widely forked fin. In the perch and bass the tail is stout, composed largely of flesh, the supporting vertebræ relatively small and spread out fan-fashion behind. Neither mackerels nor perch nor any of their near allies ever have more than five soft rays in the ventral fins, and the persistence of this number throughout the _Percomorphi_, _Squamipinnes_, _Pharyngognathi_, and spiny fishes generally must be attributed to inheritance from the primitive perch-like or mackerel-like forms. In almost all the groups to be considered in this work, after the _Berycoidea_ the ventral rays are I, 5, or else fewer through degeneration, never more. In the central or primitive members of most of these groups there are twenty-four vertebræ, the number increased in certain forms, probably through repetitive degeneration.

=The True Mackerels: Scombridæ.=—We may first consider the great central family of _Scombridæ_, or true mackerels, distinguished among related families by their swift forms, smooth scales, metallic coloration, and technically by the presence of a number of detached finlets behind the dorsal and anal fins. The cut of the mouth is peculiar, the spines in the fins are feeble, the muscular system is extremely strong, the flesh oily, and the air-bladder reduced in size or altogether wanting. As in most swift-swimming fishes and fishes of pelagic habit, the vertebræ are numerous and relatively small, an arrangement which promotes flexibility of body. It is not likely that this group is the most primitive of the scombroid fishes. In some respects the _Stromateidæ_ stand nearer the primitive stock. The true mackerels, however, furnish the most convenient point of departure in reviewing the great group.

In the genus of true mackerels, _Scomber_, the dorsal fins are well separated, the first being rather short, and the scales of the shoulders are not modified to form a corselet. There are numerous species, two of them of general interest. The common mackerel, _Scomber scombrus_, is one of the best known of food-fishes. It is probably confined to the Atlantic, where on both shores it runs in vast schools, the movements varying greatly from season to season, the preference being for cool waters. The female mackerel produces about 500,000 eggs each year, according to Professor Goode. These are very minute and each is provided with an oil-globule, which causes it to float on the surface. About 400,000 barrels of mackerel are salted yearly by the mackerel fleet of Massachusetts. Single schools of mackerel, estimated to contain a million barrels, have been recorded. Captain Harding describes such a school as "a windrow of fish half a mile wide and twenty miles long."

Professor Goode writes:

"Upon the abundance of mackerel depends the welfare of many thousands of the citizens of Massachusetts and Maine. The success of the mackerel-fishery is much more uncertain than that of the cod-fishery, for instance, for the supply of cod is quite uniform from year to year. The prospects of each season are eagerly discussed from week to week in thousands of little circles along the coast, and are chronicled by the local press. The story of each successful trip is passed from mouth to mouth, and is a matter of general congratulation in each fishing community. A review of the results of the American mackerel-fishery, and of the movements of the fish in each part of the season, would be an important contribution to the literature of the American fisheries.

"The mackerel-fishery is peculiarly American, and its history is full of romance. There are no finer vessels afloat than the American mackerel-schooners—yachts of great speed and unsurpassed for seaworthiness. The modern instruments of capture are marvels of inventive skill, and require the highest degree of energy and intelligence on the part of the fishermen. The crews of the mackerel-schooners are still for the most part Americans of the old colonial stock, although the cod and halibut fisheries are to a great extent given up to foreigners.

"When the mackerel is caught, trout, bass, and sheepshead cannot vanquish him in a gastronomic tournament. In Holland, to be sure, the mackerel is not prized, and is accused of tasting like rancid fish-oil, and in England, even, they are usually lean and dry, like the wretched skeletons which are brought to market in April and May by the southern fleet, which goes forth in the early spring from Massachusetts to intercept the schools as they approach the coasts of Carolina and Virginia. They are not worthy of the name of mackerel. _Scomber Scombrus_ is not properly in season until the spawning time is over, when the schools begin to feed at the surface in the Gulf of Maine and the 'North Bay.'

"Just from the water, fat enough to broil in its own drippings, or slightly corned in strong brine, caught at night and eaten in the morning, a mackerel or a bluefish is unsurpassable. A well-cured autumn mackerel is perhaps the finest of all salted fish, but in these days of wholesale capture by the purse-seine, hasty dressing and careless handling, it is very difficult to obtain a sweet and sound salt mackerel. Salt mackerel may be boiled as well as broiled, and a fresh mackerel may be cooked in the same manner. Americans will usually prefer to do without the sauce of fennel and gooseberry which transatlantic cooks recommend. Fresh and salt, fat and lean, new or stale, mackerel are consumed by Americans in immense quantities, as the statistics show, and whatever their state, always find ready sale."

Smaller, less important, less useful, but far more widely distributed is the chub-mackerel, or thimble-eyed mackerel, _Scomber japonicus_ (Houttuyn, 1782), usually known by the later name of _Scomber colias_ (Gmelin, 1788). In this species the air-bladder (absent in the common mackerel) is moderately developed. It very much resembles the true mackerel, but is of smaller size, less excellence as a food-fish, and keeps nearer to the shore. It may be usually distinguished by the presence of vague, dull-gray spots on the sides, where the true mackerel is lustrous silvery.

This fish is common in the Mediterranean, along our Atlantic coast, on the coast of California, and everywhere in Japan.

_Scomber antarcticus_ is the familiar mackerel of Australia. _Scomber loo_, silvery, with round black spots, is the common mackerel of the South Seas, locally known as _Ga_.

_Scomber priscus_ is a fossil mackerel from the Eocene.

_Auxis thazard_, the frigate mackerel, has the scales of the shoulders enlarged and somewhat coalescent, forming what is called a corselet. The species ranges widely through the seas of the world in great numbers, but very erratic, sometimes myriads reaching our Eastern coast, then none seen for years. It is more constant in its visits to Japan and Hawaii. Fossil species of _Auxis_ are found in the Miocene.

The genus _Gymnosarda_ has the corselet as in _Auxis_, but the first dorsal fin is long, extending backward to the base of the second. Its two species, _Gymnosarda pelamis_, the Oceanic bonito, and _Gymnosarda alleterata_, the little tunny, are found in all warm seas, being especially abundant in the Mediterranean, about Hawaii and Japan. These are plump fish of moderate size, with very red and very oily flesh.

Closely related to these is the great tunny, or Tuna (_Thunnus thynnus_) found in all warm seas and reaching at times a weight of 1500 pounds. These enormous fishes are much valued by anglers, a popular "Tuna Club" devoted to the sport of catching them with a hook having its headquarters at Avalon, on Santa Catalina Island, in California. They are good food, although the flesh of the large ones is very oily. The name horse-mackerel is often given to these monsters on the New England coast. In California, the Spanish name of tuna has become current among fisherman.

Very similar to the tuna, but much smaller, is the Albacore (_Germo alalonga_). This reaches a weight of fifteen to thirty pounds, and is known by its very long, almost ribbon-like pectoral fins. This species is common in the Mediterranean, and about the Santa Barbara Islands, where it runs in great schools in March. The flesh of the albacore is of little value, unless, as in Japan, it is eaten raw. The Japanese shibi (_Germo germo_) is another large albacore, having the finlets bright yellow. It is found also at Hawaii.

The bonito (_Sarda sarda_) wanders far throughout the Atlantic, abounding on our Atlantic coast as in the Mediterranean, coming inshore in summer to spawn or feed. Its flesh is red and not very delicate, though it may be reckoned as a fair food-fish. It is often served under the name of "Spanish mackerel" to the injury of the reputation of the better fish.

Professor Goode writes:

"One of these fishes is a marvel of beauty and strength. Every line in its contour is suggestive of swift motion. The head is shaped like a minie bullet, the jaws fit together so tightly that a knife-edge could scarcely pass between, the eyes are hard, smooth, their surfaces on a perfect level with the adjoining surfaces. The shoulders are heavy and strong, the contours of the powerful masses of muscle gently and evenly merging into the straighter lines in which the contour of the body slopes back to the tail. The dorsal fin is placed in a groove into which it is received, like the blade of a clasp-knife in its handle. The pectoral and ventral fins also fit into depressions in the sides of the fish. Above and below, on the posterior third of the body, are placed the little finlets, each a little rudder with independent motions of its own, by which the course of the fish may be readily steered. The tail itself is a crescent-shaped oar, without flesh, almost without scales, composed of bundles of rays flexible, yet almost as hard as ivory. A single sweep of this powerful oar doubtless suffices to propel the bonito a hundred yards, for the polished surfaces of its body can offer little resistance to the water. I have seen a common dolphin swimming round and round a steamship, advancing at the rate of twelve knots an hour, the effort being hardly perceptible. The wild duck is said to fly seventy miles in an hour. Who can calculate the speed of the bonito? It might be done by the aid of the electrical contrivances by which is calculated the initial velocity of a projectile. The bonitoes in our sounds to-day may have been passing Cape Colony or the Land of Fire day before yesterday."

Another bonito, _Sarda chilensis_, is common in California; in Chile, and in Japan. This species has fewer dorsal spines than the bonito of the Atlantic, but the same size, coloration, and flesh. Both are blue, with undulating black stripes along the side of the back.

The genus _Scomberomorus_ includes mackerels slenderer in form, with larger teeth, no corselet, and the flesh comparatively pale and free from oil.

_Scomberomorus maculatus_, the Spanish mackerel of the West Indies, is one of the noblest of food-fishes. Its biography was written by Mitchill almost a century ago in these words:

"A fine and beautiful fish; comes in July."

Goode thus writes of it:

"The Spanish mackerel is surely one of the most graceful of fishes. It appeals as scarcely any other can to our love of beauty, when we look upon it, as shown in Kilbourn's well-known painting, darting like an arrow just shot from the bow, its burnished sides, silver flecked with gold, thrown into bold relief by the cool green background of the rippled sea; the transparent grays, opalescent whites, and glossy blacks of its trembling fins enhance the metallic splendor of its body, until it seems to rival the most brilliant of tropical birds. Kilbourn made copies of his large painting on the pearly linings of seashells and produced some wonderful effects by allowing the natural luster of the mother-of-pearl to show through his transparent pigments and simulate the brilliancy of the life-inspired hues of the quivering, darting sea-sprite, whose charms even his potent brush could not properly depict.

"It is a lover of the sun, a fish of tropical nature, which comes to us only in midsummer, and which disappears with the approach of cold, to some region not yet explored by ichthyologists. It is doubtless very familiar in winter to the inhabitants of some region adjacent to the waters of the Caribbean or the tropical Atlantic, but until this place shall have been discovered it is more satisfactory to suppose that with the bluefish and the mackerel it inhabits that hypothetical winter resort to which we send the migratory fishes whose habits we do not understand—the middle strata of the ocean, the floating beds of Sargassum, which drift hither and thither under the alternate promptings of the Gulf-stream currents and the winter winds."

The Spanish mackerel swims at the surface in moderate schools and is caught in abundance from Cape May southward. Its white flesh is most delicious, when properly grilled, and Spanish mackerel, like pampano, should be cooked in no other way.

A very similar species, _Scomberomorus sierra_, occurs on the west coast of Mexico. For some reason it is little valued as food by the Mexicans. In California, the Monterey Spanish mackerel (_Scomberomorus concolor_) is equally excellent as a food-fish. This fish lacks the spots characteristic of most of its relatives. It was first found in the Bay of Monterey, especially at Santa Cruz and Soquel, in abundance in the autumn of 1879 and 1880. It has not, so far as is known, been seen since, nor is the species recorded from any other coast.

The true Spanish mackerel has round, bronze-black spots upon its sides. Almost exactly like it in appearance is the pintado, or sierra (_Scomberomorus regalis_), but in this species the spots are oblong in form. The pintado abounds in the West Indies. Its flesh is less delicate than that of the more true Spanish mackerel. The name _sierra_, saw, commonly applied to these fishes by Spanish-speaking people, has been corrupted into _cero_ in some books on angling.

Still other Spanish mackerel of several species occur on the coasts of India, Chile, and Japan.

The great kingfish, or cavalla (_Scomberomorus cavalla_), is a huge Spanish mackerel of Cuba and the West Indies, reaching a weight of 100 pounds. It is dark iron-gray in color, one of the best of food-fishes, and is unspotted, and its firm, rich flesh resembles that of the barracuda.

Still larger is the great guahu, or peto, an immense sharp-nosed, swift-swimming mackerel found in the East and West Indies, as well as in Polynesia, reaching a length of six feet and a weight of more than a hundred pounds. Its large knife-like teeth are serrated on the edge and the color is almost black. _Acanthocybium solandri_ is the species found in Hawaii and Japan. The American _Acanthocybium petus_, occasionally also taken in the Mediterranean, may be the same species.

Fossil Spanish mackerels, tunnies, and albacores, as well as representatives of related genera now extinct, abound in the Eocene and Miocene, especially in northern Italy. Among them are _Scomber antiquus_ from the Miocene, _Scombrinus macropomus_ from the Eocene London clays, much like _Scomber_, but with stronger teeth, _Sphyrænodus priscus_ from the same deposits, the teeth still larger, _Scombramphodon crossidens_, from the same deposits, also with strong teeth, like those of _Scomberomorus_. _Scomberomorus_ is the best represented of all the genera as fossil, _Scomberomorus speciosus_ and numerous other species occurring in the Eocene. A fossil species of _Germo_, _G. lanceolatus_, occurs at Monte Bolca in Eocene rocks. Another tunny, with very small teeth is _Eothynnus salmonens_, from the lower Eocene near London. Several other tunny-like fishes occur in the lower Tertiary.

=The Escolars: Gempylidæ.=—More predaceous than the mackerels and tunnies are the pelagic mackerels, _Gempylidæ_, known as _escolars_ ("scholars"), with the body almost band-shaped and the teeth very large and sharp. Some of these, from the ocean depths, are violet-black in color, those near the surface being silvery. _Escolar violaceus_ lives in the abysses of the Gulf Stream. _Ruvettus pretiosus_, the black escolar, lives in more moderate depths and is often taken in Cuba, Madeira, Hawaii, and Japan. It is a very large fish, black, with very rough scales. The flesh is white, soft, and full of oil; sometimes rated very high, and at other times too rank to be edible. The name _escolar_ means _scholar_ in Spanish, but its root meaning, as applied to this fish, comes from a word meaning _to scour_, in allusion to the very rough scales.

_Promethichthys prometheus_, the rabbit-fish, or conejo, so-called from its wariness, is caught in the same regions, being especially common about Madeira and Hawaii. _Gempylus serpens_, the snake-mackerel, is a still slenderer and more voracious fish of the open seas. _Thyrsites atun_ is the Australian "barracuda," a valued food-fish, voracious and predaceous.

=Scabbard-and Cutlass-fishes: Lepidopidæ and Trichiuridæ.=—The family of _Lepidopidæ_, or scabbard-fishes, includes degenerate mackerels, band-shaped, with continuous dorsal fin, and the long jaws armed with very small teeth. These are found in the open sea, _Lepidopus candatus_ being the most common. This species reaches a length of five or six feet and comes to different coasts occasionally to deposit its spawn. It lives in warm water and is at once chilled by the least cold; hence the name of frostfish occasionally applied to it. Several species of _Lepidopus_ are fossil in the later Tertiary. _Lepidopus glarisianus_ occurs in the Swiss Oligocene, and with it _Thyrsitocephalus alpinus_, which approaches more nearly to the _Gempylidæ_.

Still more degenerate are the _Trichiuridæ_, or cutlass-fishes, in which the caudal fin is wanting, the tail ending in a hair-like filament. The species are bright silvery in color, very slender, and very voracious, reaching a length of three to five feet. _Trichiurus lepturus_ is rather common on our Atlantic coast. The names hairfish and silver-eel, among others, are often given to it. _Trichiurus japonicas_, a very similar species, is common in Japan, and other species inhabit the tropical seas. _Trichiurichthys_, a fossil genus with well-developed scales, precedes _Trichiurus_ in the Miocene.

=The Palæorhynchidæ.=—The extinct family of _Palæorhynchidæ_ is found from the Eocene to the Oligocene. It contains very long and slender fishes, with long jaws and small teeth, the dorsal fin long and continuous. The species resembles the _Escolar_ on the one hand and the sailfishes on the other, and they may prove to be ancestral to the _Istiophoridæ_. _Hemirhynchus deshayesi_ with the upper jaw twice as long as the lower, sword-like, occurs in the Eocene at Paris; _Palæorhynchum glarisianum_, with the jaws both elongate, the lower longest, is in the Oligocene of Glarus. Several other species of both genera are recorded.

=The Sailfishes: Istiophoridæ.=—Remotely allied to the cutlass-fishes and still nearer to the _Palæorhynchidæ_ is the family of sailfishes, _Istiophoridæ_, having the upper jaw prolonged into a sword made of consolidated bones. The teeth are very feeble and the ventral fins reduced to two or three rays. The species are few in number, of large size, and very brilliant metallic coloration, inhabiting the warm seas, moving northward in summer. They are excellent as food, similar to the swordfish in this as in many other respects. The species are not well known, being too large for museum purposes, and no one having critically studied them in the field. _Istiophorus_ has the dorsal fin very high, like a great sail, and undivided; _Istiophorus nigricans_ is rather common about the Florida Keys, where it reaches a length of six feet. Its great sail, blue with black spots, is a very striking object. Closely related to this is _Istiophorus orientalis_ of Japan and other less known species of the East Indies.

_Tetrapturus_, the spearfish, has the dorsal fin low and divided into two parts. Its species are taken in most warm seas, _Tetrapturus imperator_ throughout the Atlantic, _Tetrapturus amplus_ in Cuba, _Tetrapturus mitsukurii_ and _Tetrapturus mazara_ in Japan. These much resemble swordfish in form and habits, and they have been known to strike boats in the same way.

Fossil _Istiophoridæ_ are known only from fragments of the snout, in Europe and America, referred provisionally to _Istiophorus_. The genus _Xiphiorhynchus_, fossil swordfishes from the Eocene, known from the skull only, may be referred to this family, as minute teeth are present in the jaws. _Xiphiorhynchus priscus_ is found in the London Eocene.

=The Swordfishes: Xiphiidæ.=—The family of swordfishes, _Xiphiidæ_, consists of a single species, _Xiphias gladius_, of worldwide distribution in the warm seas. The snout in the swordfish is still longer, more perfectly consolidated, and a still more effective weapon of attack. The teeth are wholly wanting, and there are no ventral fins, while the second of the two fins on the back is reduced to a slight finlet.

The swordfish follows the schools of mackerel to the New England coasts. "Where you see swordfish, you may know that mackerel are about," Goode quotes from an old fisherman. The swordfish swims near the surface, allowing its dorsal fin to appear, as also the upper lobe of the caudal. It often leaps out of the water, and none of all the fishes of the sea can swim more swiftly.

"The pointed head," says Goode, "the fins of the back and abdomen snugly fitting into grooves, the absence of ventrals, the long, lithe, muscular body, sloping slowly to the tail, fit it for the most rapid and forcible movement through the water. Prof. Richard Owen, testifying in an England court in regard to its power, said:

"'It strikes with the accumulated force of fifteen double-handed hammers. Its velocity is equal to that of a swivel-shot, and is as dangerous in its effects as a heavy artillery projectile.'

"Many very curious instances are on record of the encounters of this fish with other fishes, or of their attacks upon ships. What can be the inducement for it to attack objects so much larger than itself it is hard to surmise.

"It surely seems as if a temporary insanity sometimes takes possession of the fish. It is not strange that, when harpooned, it should retaliate by attacking its assailant. An old swordfish fisherman told Mr. Blackford that his vessel had been struck twenty times. There are, however, many instances of entirely unprovoked assault on vessels at sea. Many of these are recounted in a later portion of this memoir. Their movements when feeding are discussed below, as well as their alleged peculiarities of movement during the breeding season.

"It is the universal testimony of our fishermen that two are never seen swimming close together. Capt. Ashby says that they are always distant from each other at least thirty or forty feet.

"The pugnacity of the swordfish has become a byword. Without any special effort on my part numerous instances of their attacks upon vessels have in the last ten years found their way into the pigeon-hole labeled 'Swordfish.'"

Swordfishes are common on both shores of the Atlantic wherever mackerel run. They do not breed on our shores, but probably do so in the Mediterranean and other warm seas. They are rare off the California coast, but five records existing (Anacapa, Santa Barbara, Santa Catalina, San Diego, off Cerros Island). The writer has seen two large individuals in the market of Yokohama, but it is scarcely known in Japan. As a food-fish, the swordfish is one of the best, its dark-colored oily flesh, though a little coarse, making most excellent steaks. Its average weight on our coast is about 300 pounds, the maximum 625.

The swordfish undergoes great change in the process of development, the very young having the head armed with rough spines and in nowise resembling the adult.

Fossil swordfishes are unknown, or perhaps cannot be distinguished from remains of _Istiophoridæ_.