Chapter XXI: The Fishes of the Deep Sea (4)

Seven species are known, the majority of which are European, as _P. erythrinus_, common in the Mediterranean, and not rare on the south coast of England, where it is generally termed “Becker;” _P. centrodontus_, the common “Sea-bream” of the English coasts, distinguished by a black spot on the origin of the lateral line; in the young, which are called “Chad” by Cornish and Devon fishermen, this spot is absent; _P. owenii_, the “Axillary or Spanish Sea-Bream,” likewise from the British coasts. _Pagellus lithognathus_, from the coasts of the Cape of Good Hope, attains to a length of four feet, and is one of the fishes which are dried for export and sale to whalers.

CHRYSOPHRYS.--Body oblong, compressed, with scales of moderate
size. Jaws with four or six canine teeth in front, and with
three or more series of rounded molars on each side. Cheeks
scaly. The spines of the dorsal fin, eleven or twelve in number,
can be received in a groove; anal spines three.

Some twenty species are known from tropical seas and the warmer parts of the temperate zones. Generally known is _Ch. aurata_, from the Mediterranean, occasionally found on the south coast of England, where it is named “Gilthead.” The French call it “Daurade,” no doubt from the Latin _Aurata_, a term applied to it by ancient authors. The Greeks named it Chrysophrys (_i.e._ golden eyebrow), in allusion to the brilliant spot of gold which it bears between its eyes. According to Columella, the Aurata was among the number of the fishes brought up by the Romans in their vivaria; and the inventor of those vivaria, one Sergius Orata, is supposed to have derived his surname from this fish. It is said to grow extremely fat in artificial ponds. Duhamel states that it stirs up the sand with the tail, so as to discover the shell-fish concealed in it. It is extremely fond of mussels, and its near presence is sometimes ascertained by the noise which it makes while breaking their shells with its teeth. Several species found on the Cape of Good Hope attain to as large a size as _Pagellus lithognathus_, and are preserved for sale like that species. _Chrysophrys hasta_ is one of the most common species of the East Indian and Chinese coasts, and enters large rivers.

_Fifth Group--Pimelepterina._--In both jaws a single anterior series of cutting teeth, implanted by a horizontal posterior process, behind which is a band of villiform teeth. Villiform teeth on the vomer, palatines and the tongue. Vertical fins densely covered with minute scales. Only one genus is known, _Pimelepterus_, with six species from tropical seas. These fishes are sometimes found at a great distance from the land.

FIFTH FAMILY--HOPLOGNATHIDÆ.

_Body compressed and elevated, covered with very small ctenoid scales. Lateral line continuous. The bones of the jaws have a sharp dentigerous edge, as in Scarus. The teeth, if at all conspicuous, being continuous with the bone, forming a more or less indistinct serrature; no teeth on the palate. The spinous portion of the dorsal fin is rather more developed than the soft; the spines strong; anal with three spines, similar to the soft dorsal. Ventrals thoracic, with one spine and five soft rays._

One genus only is known, _Hoplognathus_, with four species from Australian, Japanese, and Peruvian coasts.

SIXTH FAMILY--CIRRHITIDÆ.

_Body oblong, compressed, covered with cycloid scales; lateral line continuous. Mouth in front of the snout, with lateral cleft. Eye lateral, of moderate size. Cheeks without a bony stay for the præoperculum. Generally six, sometimes five or three branchiostegals. Dentition more or less complete, composed of small pointed teeth, sometimes with the addition of canines. One dorsal fin, formed by a spinous and soft portion, of nearly equal development. Anal with three spines, generally less developed than the soft dorsal. The lower rays of the pectoral fins simple and generally enlarged; ventrals thoracic, but remote from the root of the pectorals, with one spine and five rays._

The fishes of this family may be readily recognised by their thickened, undivided lower pectoral rays, which in some are evidently auxiliary organs of locomotion, in others, probably, organs of touch. They differ from the following family, the Scorpænidæ, in lacking the bony connection between the infraorbital ring and the præoperculum. Two groups may be distinguished in this family, which, however, are connected by an intermediate genus (_Chironemus_). The first, distinguished by the presence of vomerine teeth, consists of _Cirrhites_ and _Chorinemus_, small prettily coloured fishes. The former genus is peculiar to the Indo-Pacific, and consists of sixteen species; the second, with three species, seems to be confined to the coasts of Australia and New Zealand. The second group lacks the vomerine teeth, and comprises the following genera:--

CHILODACTYLUS.--One dorsal fin, with from sixteen to nineteen
spines; anal fin of moderate length; caudal forked. One of the
simple pectoral rays more or less prolonged, and projecting
beyond the margin of the fin. Teeth in villiform bands; no
canines. Præoperculum not serrated. Scales of moderate size.
Air-bladder with many lobes.

Seventeen species are known, chiefly from the temperate parts of the Southern Pacific, and also from the coasts of Japan and China. They belong to the most valuable food-fishes, as they grow to a considerable size (from five to twenty-five lbs.), and are easily caught in numbers. At the Cape of Good Hope they are very abundant, and preserved in large quantities for export.

_Mendosoma_ from the coast of Chili, and _Nemadactylus_ from Tasmania, are allied genera.

LATRIS.--Dorsal fin deeply notched; the spinous portion with
seventeen spines; anal fin many-rayed. None of the simple
pectoral rays passes the margin of the fin. Teeth villiform; no
canines. Præoperculum minutely serrated. Scales small.

Two species only are known from Tasmania and New Zealand, which belong to the most important food-fishes of the Southern Hemisphere. _Latris hecateia_ or the “Trumpeter,” ranges from sixty to thirty lbs. in weight, and is considered by the colonists the best flavoured of any of the fishes of South Australia, Tasmania, and New Zealand, and consumed smoked as well as fresh. The second species, _Latris ciliaris_, is smaller, scarcely attaining a weight of twenty lbs., but more abundant; it is confined to the coast of New Zealand.

SEVENTH FAMILY--SCORPÆNIDÆ.

_Body oblong, more or less compressed, covered with ordinary scales, or naked. Cleft of the mouth lateral or subvertical. Dentition feeble, consisting of villiform teeth; and generally without canines. Some bones of the head armed, especially the angle of the præoperculum, its armature receiving additional support by a bony stay, connecting it with the infraorbital ring. The spinous portion of the dorsal fin equally or more developed than the soft and than the anal. Ventrals thoracic, generally with one spine and five soft rays, sometimes rudimentary._

This family consists of carnivorous marine fishes only; some resemble the Sea-Perches in form and habits, as _Sebastes_, _Scorpæna_, etc., whilst others live at the bottom of the sea, and possess in various degrees of development those skinny appendages resembling the fronds of seaweeds, by which they either attract other fishes, or by which they are enabled more effectually to hide themselves. Species provided with those appendages have generally a coloration resembling that of their surroundings, and varying with the change of locality. The habit of living on the bottom has also developed in many Scorpænoids separate pectoral rays, by means of which they move or feel. Some of the genera live at a considerable depth, but apparently not beyond 300 fathoms. Nearly all are distinguished by a powerful armature either of the head, or fin spines, or both; and in some the spines have been developed into poison organs.

The only fossil representative known at present is a species of _Scorpæna_ from the Eocene of Oran.

SEBASTES.--Head and body compressed; crown of the head scaly to,
or even beyond, the orbits; no transverse groove on the occiput.
Body covered with scales of moderate or small size, and without
skinny tentacles. Fin-rays not elongate; one dorsal, divided by
a notch into a spinous and soft portion, with twelve or thirteen
spines; the anal with three. No pectoral appendages. Villiform
teeth in the jaws, on the vomer, and generally on the palatine
bones. Vertebræ more than twenty-four.

About twenty species are known, principally from seas of the temperate zones, as from the coasts of Northern Europe (_S. norvegicus_, _S. viviparus_), of Japan, California, New Zealand, and Van Diemen’s Land. All seem to prefer deep water to the surface, and _Sebastes macrochir_ has been obtained at a depth of 345 fathoms. In their general form they resemble the Sea-Perches, attain to a weight of from one to four lbs., and are generally esteemed as food.

SCORPÆNA.--Head large, slightly compressed, generally with a
transverse naked depression on the occiput; bones of the head
armed with spines, and generally with skinny tentacles. Scales
of moderate size. Mouth large, oblique. Villiform teeth in the
jaws, and at least on the vomer. One dorsal, 12–13/9, A. 3/5.
Pectoral fins without detached rays, large, rounded, with the
lower rays simple and thickened. Air-bladder none. Vertebræ
twenty-four.

About forty species are known from tropical and sub-tropical seas. They lead a sedentary life, lying hidden in the sand, or between rocks covered with seaweed, watching for their prey, which chiefly consists of small fishes. Their strong undivided pectoral rays aid them in burrowing in the sand, and in moving along the bottom. The type of their coloration is very much the same in all the species, viz. an irregular mottling of red, yellow, brown, and black colours, but the distribution of these colours varies exceedingly, not only in the same species but also in the same individuals. They do not attain to any considerable size, probably never exceeding a length of 18 inches. Their flesh is well flavoured. Wounds inflicted by their fin-spines are exceedingly painful, but not followed by serious consequences.

_Glyptauchen_ and _Lioscorpius_ are genera closely allied to _Scorpæna_, from Australian seas.

_Setarches_ is also allied to the preceding genera, and provided with very large eyes, in accordance with the depth (215 fathoms) which the two species known at present inhabit; one has been found near Madeira, the other near the Fiji Islands.

PTEROIS.--Head and body compressed; scales of small or moderate
size. Bones of the head armed with numerous spinous projections,
between which often skinny tentacles are developed. The dorsal
spines and pectoral rays are more or less prolonged, passing
beyond the margin of the connecting membrane. Twelve or thirteen
dorsal spines. Villiform teeth in the jaws and on the vomer.

Nine species are known from the tropical Indo-Pacific. They belong to the most singularly formed and most beautifully coloured fishes of the Tropics, and formerly were believed to be able to fly, like Dactylopterus. But the membrane connecting their pectoral rays is much too short and feeble to enable them to raise themselves from the surface of the water.

APISTUS.--Head and body compressed, covered with ctenoid scales
of rather small size. Some bones of the head, and especially
the præorbital, are armed with spines. One dorsal with fifteen
spines; the anal with three. The pectoral fin is elongate, and
one ray is completely detached from the fin. Villiform teeth in
the jaws, on the vomer, and palatine bones. Air-bladder present.
A cleft behind the fourth gill.

Two species from the Indian Ocean. These fishes are very small, but of interest on account of the prolongation of their pectoral fins, which indicates that they can take long flying leaps out of the water. However, this requires confirmation by actual observation.

AGRIOPUS.--Head and body compressed, scaleless; head without
any, or with very feeble, armature. Cleft of the mouth small, at
the end of the produced snout. One dorsal fin, which commences
from the head, the spinous portion being formed by from
seventeen to twenty-one strong spines; anal short. Villiform
teeth in the jaws, generally none on the vomer.

Seven species. This singular genus is peculiar to the temperate parts of the South Pacific, occurring at the Cape, on the coast of South Australia, and Chili. The largest species (_A. torvus_) attains a length of two and a half feet. Nothing is known of its mode of life.

SYNANCEIA.--General appearance of the fish, especially of the
head, monstrous. Scales none; skin with numerous soft warty
protuberances or filaments. Mouth directed upwards, wide. Eyes
small. From thirteen to sixteen dorsal spines; pectoral fins
very large. Villiform teeth in the jaws, and sometimes on the
vomer.

Four species are known from the Indo-Pacific, of which _S. horrida_ and _S. verrucosa_ are the most generally distributed, and, unfortunately, the most common. They are justly feared on account of the great danger accompanying wounds which they inflict with their poisoned dorsal spines, as has been already noticed above, p. 191. The greatest length to which they attain does not seem to exceed eighteen inches. They are very voracious fishes, and their stomach is of so great a capacity that they are able to swallow fishes one-third of their own bulk.

MICROPUS.--Head and body strongly compressed, short, and deep;
no scales, but the skin is covered with minute tubercles. Snout
very short, with nearly vertical anterior profile. Præorbital,
præ- and inter-operculum with spines on the edge. Dorsal fin
with seven or eight, anal with two spines. Pectorals short,
ventrals rudimentary. Jaws with villiform teeth.

These fishes belong to the smallest of Acanthopterygians, scarcely exceeding 1½ inches in length. Two species are known, which are rather common on the coral reefs of the Pacific.

CHORISMODACTYLUS.--Head and body rather compressed,
scaleless, with skinny flaps. Bones of the head with prominent
ridges; the præorbital, præoperculum, and operculum armed; a
depression on the occiput. One dorsal fin, with thirteen spines;
the anal with two. Three free pectoral appendages. Ventral fins
with one spine and five rays. Villiform teeth in the jaws only.

Only one small species, _Ch. multibarbis_, is known, from the coasts of India and China.

To complete the list of Scorpænoid genera, we have to mention _Tænianotus_, _Centropogon_, _Pentaroge_, _Tetraroge_, _Prosopodasys_, _Aploactis_, _Trichopleura_, _Hemitripterus_, _Minous_ and _Pelor_.

EIGHTH FAMILY--NANDIDÆ.

_Body oblong, compressed, covered with scales. Lateral line interrupted. Dorsal fin formed by a spinous and soft portion, the number of spines and rays being nearly equal; anal fin with three spines, and with the soft portion similar to the soft dorsal. Ventral fins thoracic, with one spine, and five or four rays. Dentition more or less complete, but feeble._

This small family consists of two very distinct groups.

A. _Plesiopina._ Marine fishes of small size, with pseudobranchiæ and only four ventral rays. _Plesiops_ from the coral-reefs of the Indo-Pacific, and _Trachinops_ from the coast of New South Wales, belong to this group.

B. _Nandina._ Freshwater fishes of small size from the East Indies, without pseudobranchiæ, and five ventral rays. The genera are _Badis_, _Nandus_, and _Catopra_.

NINTH FAMILY--POLYCENTRIDÆ.

_Body compressed, deep, scaly. Lateral line none. Dorsal and anal fins long, both with numerous spines, the spinous portion being the more developed. Ventrals thoracic, with one spine and five soft rays. Teeth feeble. Pseudobranchiæ hidden._

Only two genera, each represented by one or two species in the Atlantic rivers of Tropical America, _Polycentrus_ and _Monocirrhus_, belong to this family. They are small insectivorous fishes.

TENTH FAMILY--TEUTHIDIDÆ.

_Body oblong, strongly compressed, covered with very small scales. Lateral line continuous. Eye lateral, of moderate size. A single series of cutting incisors in each jaw; palate toothless. One dorsal fin, the spinous portion being the more deve__loped; anal with seven spines. Ventral fins thoracic, with an outer and an inner spine, and with three soft rays between._

This family consists of one very natural genus, _Teuthis_, readily recognised by the singular structure of the fins. In all the species the fin-formula is D. 13/10. A. 7/9. The incisors are small, narrow, and provided with a serrated edge. The air-bladder is large, and forked anteriorly as well as posteriorly. Their skeleton shows several peculiarities: the number of vertebræ is twenty-three, ten of which belong to the abdominal portion. The abdominal cavity is surrounded by a complete ring of bones, the second piece of the coracoid being exceedingly long, and extending along the whole length of the abdomen, where it is joined to a spinous process of the first interhæmal. The pubic bones are slender, long, firmly attached to each other, without leaving a free space between them. They are fastened by a long process which passes the symphysis of the radii, and extends on to that of the humeri.

Thirty species are known, all from the Indo-Pacific; but they do not extend eastwards beyond 140° long., or to the Sandwich Islands. They are herbivorous, and do not exceed a length of fifteen inches.

SECOND DIVISION--ACANTHOPTERYGII BERYCIFORMES.

_Body compressed, oblong, or elevated; head with large muciferous cavities which are covered with a thin skin. Ventral fins thoracic, with one spine and more than five soft rays_ (_in_ Monocentris _with two only_).

One family only belongs to this division.

FAMILY--BERYCIDÆ.

_Body short, with ctenoid scales, which are rarely absent. Eyes lateral, large_ (_except_ Melamphaës). _Cleft of the mouth lateral, oblique; jaws with villiform teeth; palate generally toothed. Opercular bones more or less armed. Eight (four) branchiostegals._

This family offers several points of biological interest. All its members are strictly marine; but only two of the genera are surface-forms (_Holocentrum_ and _Myripristis_). All the others descend considerably below the surface, and even some of the species of _Myripristis_ habitually inhabit depths of from 50 to 100 fathoms. _Polymixia_ and _Beryx_ have been found in 345 fathoms. _Melamphaës_ must live at a still greater depth, as we may infer from the small size of its eye; this fish is not likely to come nearer to the surface than to about 200 fathoms. The other genera named have extremely large eyes, and, therefore, may be assumed to ascend into such superficial strata as are still lit up by a certain proportion of sun-rays. The highly-developed apparatus for the secretion of superficial mucus, with which these fishes are provided, is another sign of their living at a greater depth than any of the preceding families of Acanthopterygians. In accordance with this vertical distribution, Berycoid fishes have a wide horizontal range, and several species occur at Madeira as well as in Japan.

Fossil Berycoids show a still greater diversity of form than living; they belong to the oldest Teleosteous fishes, the majority of the Acanthopterygians found in the chalk being representatives of this family. _Beryx_ has been found in several species, with other genera now extinct: _Pseudoberyx_, with abdominal ventrals, from Mount Lebanon; _Berycopsis_, with cycloid scales; _Homonotus_, _Stenostoma_, _Sphenocephalus_, _Acanus_, _Hoplopteryx_, _Platycornus_, with granular scales; _Podocys_, with a dorsal fin extending to the neck; _Acrogaster_, _Macrolepis_, and _Rhacolepis_, from the chalk of Brazil. Species of _Holocentrum_ and _Myripristis_ occur in the Monte Bolca formation.

MONOCENTRIS.--Snout obtuse, convex, short; eye of moderate size.
Villiform teeth on the palatine bones, but none on the vomer.
Opercular bones without armature. Scales very large, bony,
forming a rigid carapace. Ventrals reduced to a single strong
spine and a few rudimentary rays.

One species only is known (_M. japonicus_) from the seas off Japan and Mauritius. It does not attain to any size, and is not common.

HOPLOSTETHUS.--Snout very short and obtuse; eye large.
Villiform teeth on the palatine bones, but none on the vomer.
Operculum unarmed, a strong spine at the scapulary and the angle
of the præoperculum. Scales ctenoid, of moderate size; abdominal
edge serrated. One dorsal, with six spines; ventrals with six
soft rays; caudal deeply forked.

One species only is known (_H. mediterraneus_), which occurs in the Mediterranean, the neighbouring parts of the Atlantic, and in the sea off Japan.

TRACHICHTHYS.--Snout very short and obtuse, with prominent chin;
eye large. Villiform teeth on the palatine bones and on the
vomer. A strong spine at the scapulary and at the angle of the
præoperculum. Scales rather small; abdomen serrated. One dorsal,
with from three to six spines; ventral with six soft rays.
Caudal forked.

Four species are known from New Zealand and Madeira.

_Anoplogaster_ is an allied genus from tropical parts of the Atlantic; it is scaleless.

BERYX.--Snout short, with oblique cleft of the mouth and
prominent chin; eye large. Villiform teeth on the palatine bones
and vomer. Opercular bones serrated; no spine at the angle of
the præoperculum. Scales ctenoid, of moderate or large size. One
dorsal, with several spines; ventrals with seven or more soft
rays. Anal with four spines; caudal forked.

Five species are known from Madeira, the tropical Atlantic, and the seas of Japan and Australia. The species figured is _B. decadactylus_, common at Madeira, and occurring near Japan at a depth of 345 fathoms; it attains a length of 1½ feet.

MELAMPHAES.--Head large and thick, with very thin bones, nearly
all the superficial bones being transformed into wide muciferous
channels. Eye small. Palate toothless; no barbels; opercles not
armed. Scales large, cycloid. One dorsal, with six spines; anal
spines very feeble; caudal forked. Ventrals with seven rays.

Two species, deep-sea fishes of the Atlantic; they are very scarce, as only three or four specimens have been found hitherto.

POLYMIXIA.--Snout short, with the cleft of the mouth nearly
horizontal; eye large. Two barbels at the throat. Opercles
without armature. Scales of moderate size. One dorsal. Anal with
three or four spines; caudal forked; ventrals with six or seven
soft rays.

Three species are known: _P. nobilis_ from Madeira and St. Helena, _P. lowei_ from Cuba, and _P. japonica_ from Japan; the latter species from a depth of 345 fathoms. Average size eighteen inches.

MYRIPRISTIS.--Snout short, with oblique cleft of the mouth and
prominent chin; eye large or very large. Villiform teeth on the
vomer and palatine bones. Opercular bones serrated; præoperculum
without spine. Scales large, ctenoid. Two dorsals, the first
with ten or eleven spines; anal with four spines; caudal
forked; ventrals with seven soft rays. Air-bladder divided by
a contraction in two parts, the anterior of which is connected
with the organ of hearing.

Eighteen species from the tropical seas of both hemispheres, the majority living near the coast at the surface. The coloration is (principally) red or pink on the back and silvery on the sides. They attain a length of about 15 inches, and are esteemed as food.

HOLOCENTRUM.--Snout somewhat projecting, with the cleft of
the mouth nearly horizontal; eye large. Villiform teeth on
the vomer and palatine bones. Opercular bones and præorbital
serrated; operculum with two spines behind; a large spine at the
angle of the præoperculum. Scales ctenoid, of moderate size. Two
dorsals, the first with twelve spines; anal with four spines,
the third being very long and strong; caudal forked. Ventrals
with seven soft rays.

About thirty species are known from the tropical seas of both hemispheres; all are surface fishes, and very common. The young have the upper part of the snout pointed and elongate, and were described as a distinct genus (_Rhynchichthys_). The coloration of the adult is uniform; red, pink, and silvery prevailing. They attain to a length of about 15 inches, and are esteemed as food.

THIRD DIVISION--ACANTHOPTERYGII KURTIFORMES.

_One dorsal fin only, much shorter than the anal, which is long and many-rayed. No superbranchial organ._

One family only belongs to this division.

FAMILY--KURTIDÆ.

_Body compressed, oblong, deep in front, attenuated behind. Snout short. The spines of the short dorsal are few in number, if developed. Scales small or of moderate size. Villiform teeth in the jaws, on the vomer, and palatine bones._

This family consists of a small number of species only, which form two distinct genera, _Pempheris_ and _Kurtus_. They are shore fishes of tropical seas. In both the air-bladder shows some peculiarity: in _Pempheris_ it is divided into an anterior and posterior portion; in _Kurtus_ it is lodged within the ribs, which are dilated, convex, forming rings. The number of vertebræ is respectively twenty-four and twenty-three.

FOURTH DIVISION--ACANTHOPTERYGII POLYNEMIFORMES.

_Two rather short dorsal fins, somewhat remote from each other; free filaments at the humeral arch, below the pectoral fins; muciferous canals of the head well developed._

One family only belongs to this division.

FAMILY--POLYNEMIDÆ.

_Body oblong, rather compressed, covered with smooth or very feebly ciliated scales. Lateral line continuous. Snout projecting beyond the mouth, which is inferior, with lateral cleft. Eye lateral, large. Villiform teeth in the jaws and on the palate. Ventrals thoracic, with one spine and five rays._

The fishes of this natural family have been divided, on slight differences, into three genera--_Polynemus_, _Pentanemus_, and _Galeoides_. They are found in rather numerous species on the coasts between the tropics, and the majority enter brackish or even fresh water. Very characteristic are the free filaments which in this family are organs of touch; they are inserted on the humeral arch at some distance from the pectoral fin; but, nevertheless, can be regarded only as a detached portion of that fin; they can be moved quite independently of the fin; their number varies from three to fourteen, according to the species; in some they are exceedingly elongate, twice as long as the fish, in others they are not longer or even shorter than the pectoral. It is evident from the whole organisation of these fishes that they live on muddy bottom or in thick water, such as is found near the mouths of great rivers. Their eyes are large, but generally obscured by a filmy skin, so that those feelers must be of great use to them in finding their way and their food. The Polynemoids are very useful to man: their flesh is esteemed, and some of the species are provided with an air-bladder which yields a good sort of isinglass, and forms an article of trade in the East Indies. Some of these fishes attain to a length of four feet.

FIFTH DIVISION--ACANTHOPTERYGII SCIÆNIFORMES.

_The soft dorsal is more, generally much more, developed than the spinous, and than the anal. No pectoral filaments; head with the muciferous canals well developed._

Also this division is composed of one family only.

FAMILY--SCIÆNIDÆ.

_Body rather elongate, compressed, covered with ctenoid scales. Lateral line continuous, and frequently extending over the caudal fin. Mouth in front of the snout. Eye lateral, of moderate size. Teeth in villiform bands, sometimes with the addition of canines; no molars or incisor-like teeth in the jaws; palate toothless. Præoperculum unarmed, and without bony stay. Ventrals thoracic, with one spine and five soft rays. Bones of the head with wide muciferous channels. Stomach coecal. Air-bladder frequently with numerous appendages_ (see pp. 144 and _seq._)

The fishes of the “_Meagre_” family are chiefly coast-fishes of the tropical and sub-tropical Atlantic and Indian Oceans, preferring the neighbourhood of the mouths of large rivers, into which they freely enter, some of the species having become so completely naturalised in fresh water that they are never found nowadays in the sea. Some of the larger species wander far from their original home, and are not rarely found at distant localities as occasional visitors. In the Pacific and on the coast of Australia, where but a few large rivers enter the ocean, they are extremely rare and, in the Red Sea, they are absent. Many attain a large size, and almost all are eaten.

No fossil species have been as yet discovered.

POGONIAS.--Snout convex, with the upper jaw overlapping the
lower. Mandible with numerous small barbels. No canines. The
first dorsal with ten stout spines. Two anal spines, the second
very strong. Scales of moderate size.

To this fish (_P. chromis_) more especially is given the name of “Drum,” from the extraordinary sounds which are produced by it and other allied Sciænoids. These sounds are better expressed by the word drumming than by any other, and are frequently noticed by persons in vessels lying at anchor on the coasts of the United States, where those fishes abound. It is still a matter of uncertainty by what means the “Drum” produces the sounds. Some naturalists believe that it is caused by the clapping together of the pharyngeal teeth, which are very large molar teeth. However, if it be true that the sounds are accompanied by a tremulous motion of the vessel, it seems more probable that they are produced by the fishes beating their tails against the bottom of the vessel in order to get rid of the parasites with which that part of their body is infested. The “Drum” attains to a length of more than four feet, and to a weight exceeding a hundred lbs. Its air-bladder has been figured on p. 146.

_Micropogon_ is closely allied to _Pogonias_, but has conical pharyngeal teeth. Two species from the western parts of the Atlantic.

UMBRINA.--Snout convex, with the upper jaw overlapping the
lower; a short barbel under the symphysis of the mandible. The
first dorsal with nine or ten flexible spines, the anal with one
or two. Scales of moderate size.

Twenty species are known from the Mediterranean, Atlantic, and Indian Ocean. One well known to the ancients, under the name of _Umbra_, is the _Umbrina cirrhosa_ of the Mediterranean, the “Umbrine” or “Ombre” of the French, and the “Corvo” of the Italians. It ranges to the Cape of Good Hope, and attains a length of three feet. Also on the coasts of the United States several species occur, as _U. alburna_, _U. nebulosa_, etc.

SCIÆNA (including _Corvina_).--The upper jaw overlapping
the lower, or both jaws equal in front. Interorbital space
moderately broad and slightly convex. Cleft of the mouth
horizontal or slightly oblique. The outer series of teeth is
generally composed of teeth larger than the rest, but there are
no canines. Eye of moderate size, barbel none.

Some fifty species are known, but their distinctive characters have been but imperfectly pointed out. They are found in all the seas and rivers in which Sciænoids generally occur, and many are entirely confined to fresh water, for instance the species figured, _Sciæna richardsonii_, from Lake Huron; _Sc. amazonica_; _Sc. obliqua_, _ocellata_, _oscula_, etc., from fresh waters of the United States. _Sciæna diacanthus_ and _Sc. coitor_ belong to the most common fishes of the coasts of the East Indies, ascending the great rivers for a long distance from the sea. One of the European species, _Sciæna aquila_, has an extremely wide range; it not rarely reaches the British coasts, where it is known as “Meagre,” and has been found at the Cape of Good Hope and on the coast of southern Australia. Like some of the other species it attains to a length of six feet, but the majority of the species of this genus remain within smaller dimensions. A part of the species have the second anal ray very strong, and have been placed into a distinct genus, _Corvina_,--thus, among others, _Sc. nigra_ from the Mediterranean, and _Sc. richardsonii_.

_Pachyurus_ is closely allied to _Sciæna_, but has the vertical fins densely covered with small scales.

OTOLITHUS.--Snout obtuse or somewhat pointed, with the lower jaw
longer. The first dorsal with nine or ten feeble spines. Canine
teeth more or less distinct. Præoperculum denticulated. Scales
of moderate or small size.

About twenty species are known from the tropical and sub-tropical parts of the Atlantic and Indian Oceans. The air-bladder is figured on p. 144.

ANCYLODON differs from _Otolithus_ in having very long
arrow-shaped or lanceolate canine teeth. Coasts of tropical
America.

COLLICHTHYS.--Body elongate; head very broad, with the upper
surface very convex; cleft of the mouth wide and oblique;
no large canines. Eye small. No barbel. Scales small, or of
moderate size. The second dorsal very long, caudal pointed.

Three species from the East Indian and Chinese coasts. The great development of the muciferous system on the head and the small eye leads one to suppose that these fishes live in muddy water near the mouths of large rivers. The air-bladder has been described on p. 144.

Other genera belonging to this family are _Larimus_, _Eques_, _Nebris_, and _Lonchurus_.

SIXTH DIVISION--ACANTHOPTERYGII XIPHIIFORMES.

_The upper jaw is produced into a long cuneiform weapon._

These fishes form one small family only, _Xiphiidæ_.

The “Sword-fishes” are pelagic fishes, occurring in all tropical and sub-tropical seas. Generally found in the open ocean, always vigilant, and endowed with extraordinary strength and velocity, they are but rarely captured, and still more rarely preserved. The species found in the Indian and Pacific Oceans belong to the genus _Histiophorus_, distinguished from the common Mediterranean Sword-fish, or _Xiphias_, by the presence of ventral fins, which, however, are reduced to two long styliform appendages. The distinction of the species is beset with great difficulties, owing to the circumstance that but few examples exist in museums, and further, because the form of the dorsal fin, the length of the ventrals, the shape and length of the sword, appear to change according to the age of the individuals. Some specimens or species have only the anterior dorsal rays elevated, the remainder of the fin being very low, whilst in others all the rays are exceedingly elongate, so that the fin, when erected, projects beyond the surface of the water. It is stated that Sword-fishes, when quietly floating with the dorsal fin erect, can sail before the wind, like a boat.

Sword-fishes are the largest of Acanthopterygians, and not exceeded in size by any other Teleostean; they attain to a length of from 12 to 15 feet, and swords have been obtained more than three feet long, and with a diameter of at least three inches at the base. The sword is formed by the prolongation and coalescence of the maxillary and intermaxillary bones; it is rough at its lower surface, owing to the development of rudimentary villiform teeth, very hard and strong, and forms a most formidable weapon. Sword-fishes never hesitate to attack whales and other large Cetaceans, and by repeatedly stabbing these animals generally retire from the combat victorious. The cause which excites them to those attacks is unknown; but they follow this instinct so blindly that they not rarely attack boats or large vessels in a similar manner, evidently mistaking them for Cetaceans. Sometimes they actually succeed in piercing the bottom of a ship, endangering its safety; but as they are unable to execute powerful backward movements they cannot always retract their sword, which is broken off by the exertions of the fish to free itself. A piece of a two-inch plank of a whale-boat, thus pierced by a sword-fish, in which the broken sword still remains, is preserved in the British Museum.

The Rev. Wyatt Gill, who has worked as a missionary for many years in the South Sea Islands, communicates that young Sword-fishes are easily caught in strong nets, but no net is strong enough to hold a fish of six feet in length. Specimens of that size are now and then captured by hook and line, a small fish being used as bait. Individuals with the sword broken off are not rarely observed. Larger specimens cannot be captured by the natives, who are in great fear of them. They easily pierce their canoes, and only too often dangerously wound persons sitting in them.

The Mediterranean Sword-fish is constantly caught in the nets of the Tunny-fishers off the coast of Sicily, and brought to market, where its flesh sells as well as that of the Tunny.

The remarkable changes which Sword-fishes undergo at an early stage of their growth have been noticed above, p. 173 and _seq._

Sword-fishes are as old a type as the Berycoids. Their remains have been found in the chalk of Lewes, and more frequently in the London clay of Sheppy, where an extinct genus, _Coelorhynchus_, has been recognised.

SEVENTH DIVISION--ACANTHOPTERYGII TRICHIURIFORMES.

_Body elongate, compressed or band-like; cleft of the mouth wide, with several strong teeth in the jaws or on the palate. The spinous and soft portions of the dorsal fin and the anal are of nearly equal extent, long, many-rayed, sometimes terminating in finlets; caudal fin forked, if present._

FAMILY--TRICHIURIDÆ.

Marine fishes inhabiting the tropical and sub-tropical seas; some of them are surface-fishes, living in the vicinity of the coast, whilst others descend to moderate depths, as the Berycoids. All are powerful rapacious fishes, as is indicated by their dentition.

The oldest of the extinct genera are _Enchodus_ and _Anenchelum_; they were formerly referred to the Scombroids, but belong to this family. The former has been found in the chalk of Lewes and Mæstricht; the latter is abundant in the Eocene schists of Glaris. _Anenchelum_ is much elongate, and exhibits in the slender structure of its bones the characteristics of a deep-sea fish; it resembles much _Lepidopus_, but has some long rays in the ventrals. Other Eocene genera are _Nemopteryx_ and _Xiphopterus_. In the Miocene of Licata in Sicily _Trichiuridæ_ are well represented, viz. by a species of _Lepidopus_, and by two genera, _Hemithyrsites_ and _Trichiurichthys_, which are allied to _Thyrsites_ and _Trichiurus_, but covered with scales.

The following is a complete list of the genera referred to this family:--

NEALOTUS.--Body incompletely clothed with delicate scales. Small
teeth in the jaws and on the palatine bones; none on the vomer.
Two dorsal fins, the first continuous and extending to the
second; finlets behind the second and anal fins. Each ventral
fin represented by a single small spine. A dagger-shaped spine
behind the vent. Caudal fin well developed.

One specimen only of this fish (_N. tripes_), 10 inches long, has been obtained off Madeira; it evidently lives at a considerable depth, and comes to the surface only by accident.

NESIARCHUS.--Body covered with small scales. Several strong
fangs in the jaws; no teeth on the palate. First dorsal not
extending to the second. No detached finlets. Ventrals small,
but perfectly developed, thoracic. Caudal fin present. A
dagger-shaped spine behind the vent.

A rather large fish (_N. nasutus_), very rarely found in the sea off Madeira. The two or three specimens found hitherto measure from three to four feet in length. Probably living at the same depth as the preceding genus.

APHANOPUS.--Scales none. Two very long dorsal fins; caudal well
developed; ventrals none. A strong dagger-shaped spine behind
the vent. Strong teeth in the jaws; none on the palate.

One species only is known, named _A. carbo_ from its coal-black colour; it is evidently a deep-sea fish, very rarely obtained in the sea off Madeira. Upwards of four feet long.

EUOXYMETOPON.--Body naked, very long and thin. Profile of the
head regularly decurved from the nape to the snout, the occiput
and forehead being elevated and trenchant. Jaws with fangs;
palatine teeth present. One dorsal only, continued from the head
to the caudal fin, which is distinct. A dagger-shaped spine
behind the vent. Pectoral fins inserted almost horizontally,
with the lowest rays longest, and with the posterior border
emarginate. Ventral fins rudimentary, scale-like.

This is another deep-sea form of this family, but, at present, no observations have been made as regards the exact depth at which it occurs. A specimen has been known since the year 1812; it was found on the coast of Scotland, and described as _Trichiurus lepturus_. The same species has been re-discovered in the West Indies, where, however, it is also extremely scarce.

LEPIDOPUS.--Body band-like; one single dorsal extends along
the whole length of the back; caudal well developed. Ventrals
reduced to a pair of scales. Scales none. Several fangs in the
jaws; teeth on the palatine bones.

The Scabbard-fish (_L. caudatus_) is rather common in the Mediterranean and warmer parts of the Atlantic, extending northwards to the south coast of England, where it is an occasional visitor, and southwards to the Cape of Good Hope. More recently it has been observed on the coasts of Tasmania and New Zealand. We may, therefore, justly consider it to be a deep-sea fish, which probably descends to the same depth as the preceding allied forms. It grows to a length of five or six feet, but its body is so much compressed that it does not weigh more than as many pounds. It is well known in New Zealand, where it is called “Frost-fish,” and esteemed as the most delicious fish of the colony. A still more attenuated species (_L. tenuis_) occurs in the sea off Japan, at a depth of some 340 fathoms.

TRICHIURUS.--Body band-like, tapering into a fine point, without
caudal fin. One single dorsal extending the whole length of the
back. Ventrals reduced to a pair of scales, or entirely absent.
Anal fin rudimentary, with numerous extremely short spines,
scarcely projecting beyond the skin. Long fangs in the jaws;
teeth on the palatine bones, none on the vomer.

The “Hairtails” belong to the tropical marine fauna, and although generally found in the vicinity of land, they wander frequently out to sea, perhaps merely because they follow some ocean-currents. Therefore they are not rarely found in the temperate zone, the common West Indian species (_T. lepturus_), for instance, on the coast of England. They attain to a length of about four feet. The number of their vertebræ is very large, as many as 160, and more. Six species are known.

EPINNULA.--Body rather elongate, covered with minute scales,[*.
see below] The first dorsal fin continuous, with spines of
moderate strength, and extending on to the second; finlets none;
ventrals well developed. Lateral lines two. Teeth of the jaws
strong; palatine teeth, none.

The “Domine” of the Havannah, _E. magistralis_.

THYRSITES.--Body rather elongate, for the greater part naked.
The first dorsal continuous, with the spines of moderate
strength, and extending on to the second. From two to six
finlets behind the dorsal and anal. Several strong teeth in the
jaws; teeth on the palatine bones.

The species of this genus attain to a considerable size (from four to five feet), and are valuable food fishes; _Th. atun_ from the Cape of Good Hope, South Australia, New Zealand, and Chili, is preserved, pickled or smoked. In New Zealand it is called “Barracuda” or “Snoek,” and exported from the colony into Mauritius and Batavia as a regular article of commerce, being worth over £17 a ton; _Th. pretiosus_, the “Escholar” of the Havannah, from the Mediterranean, the neighbouring parts of the Atlantic, and the West Indies; _Th. prometheus_ from Madeira, Bermuda, St. Helena, and Polynesia; _Th. solandri_ from Amboyna and Tasmania is probably the same as _Th. prometheus_.

Young specimens of this (or, perhaps, the following) genus have been described as _Dicrotus_. In them the finlets are not yet detached from the rest of the fin; and the ventral fins, which are entirely obsolete in the adult fish, are represented by a long crenulated spine.

GEMPYLUS.--Body very elongate, scaleless. The first dorsal fin
continuous, with thirty and more spines, and extending on to the
second. Six finlets behind the dorsal and anal. Several strong
teeth in the jaws, none on the palate.

One species (_G. serpens_), inhabiting considerable depths of the Atlantic and Pacific Oceans.

FAMILY--PALÆORHYNCHIDÆ.

This family has been formed for two extinct genera: _Palæorhynchus_ from the schists of Glaris, and _Hemirhynchus_ from tertiary formations near Paris. These genera resemble much the _Trichiuridæ_ in their long, compressed body, and long vertical fins, but their jaws, which are produced into a long beak, are toothless, or provided with very small teeth. The dorsal fin extends the whole length of the back, and the anal reaches from the vent nearly to the caudal, which is forked. The ventrals are composed of several rays and thoracic. The vertebræ long, slender, and numerous, and, like all the bones of the skeleton, thin, indicating that these fishes were inhabitants of considerable depths of the ocean. Both the jaws of _Palæorhynchus_ are prolonged into a beak, whilst in _Hemirhynchus_ the upper exceeds the lower in length.

EIGHTH DIVISION--ACANTHOPTERYGII COTTO-SCOMBRIFORMES.

_Spines developed, in one of the fins at least. Dorsal fins either continuous or close together; the spinous dorsal, if present, always short; sometimes modified into tentacles, or into a suctorial disk; soft dorsal always long, if the spinous is absent; anal similarly developed as the soft dorsal, and both generally much longer than the spinous, sometimes terminating in finlets. Ventrals, thoracic or jugular, if present, never modified into an adhesive apparatus. No prominent anal papilla._

Marine fishes, with few exceptions.

FIRST FAMILY--ACRONURIDÆ.

_Body compressed, oblong or elevated, covered with minute scales. Tail generally armed with one or more bony plates or spines, which are developed with age, but absent in very young individuals. Eye lateral, of moderate size. Mouth small; a single series of more or less compressed, sometimes denticulated, sometimes pointed incisors in each jaw; palate toothless. One dorsal fin, the spinous portion being less developed than the soft; anal with two or three spines; ventral fins thoracic. Air-bladder forked posteriorly. Intestines with more or less numerous circumvolutions. Nine abdominal, and thirteen caudal vertebræ._

Inhabitants of the tropical seas, and most abundant on coral-reefs. They feed either on vegetable substances or on the superficial animal matter of corals.

Extinct species of _Acanthurus_ and _Naseus_ have been discovered in the Monte Bolca formation.

ACANTHURUS.--Jaws with a single series of lobate incisors, which
are sometimes movable. An erectile spine hidden in a groove on
each side of the tail. Ventral fins with one spine and generally
five rays. Scales ctenoid, sometimes with minute spines.
Branchiostegals five.

The fishes of this genus, which sometimes are termed “Surgeons,” are readily recognised by the sharp lancet-shaped spine with which each side of the tail is armed. When at rest the spine is hidden in a sheath; but it can be erected and used by the fish as a very dangerous weapon, by striking with the tail towards the right and left. “Surgeons” occur in all tropical seas, with the exception of the eastern part of the Pacific, where they disappear with the corals. They do not attain to any size, the largest species scarcely exceeding a length of eighteen inches. Many are agreeably or showily coloured, the ornamental colours being distributed in very extraordinary patterns. The larger species are eatable, and some even esteemed as food. It is stated that the fry of some species periodically approaches, in immense numbers, the coasts of some of the South Sea Islands (Caroline Archipelago), and serves as an important article of food to the natives. Nearly fifty species are known.

At an early period of their growth these fishes present so different an aspect that they were considered a distinct genus, _Acronurus_. The form of the body is more circular and exceedingly compressed. No scales are developed, but the skin forms numerous oblique parallel folds. The gill-cover and the breast are shining silvery.

NASEUS.--Tail with two (rarely one or three) bony keeled plates
on each side (in the adult). Head sometimes with a bony horn or
crest-like prominence directed forwards. Ventral fins composed
of one spine and three rays. From four to six spines in the
dorsal; two anal spines. Scales minute, rough, forming a sort of
fine shagreen. Air-bladder forked behind. Intestinal tract with
many circumvolutions.

Twelve species are known from the tropical Indo-Pacific, but none of them extend eastwards beyond the Sandwich Islands. In their mode of life these fishes resemble the _Acanthuri_. Likewise, the young have a very different appearance, and are unarmed, and were described as a distinct genus, _Keris_. One of the most common species is _N. unicornis_, which, when adult (22 inches long), has a horn about 2 inches long, whilst it is merely a projection in front of the eye in individuals of 7 inches in length.

_Prionurus_ is an allied genus with a series of several keeled bony laminæ on each side of the tail.

SECOND FAMILY--CARANGIDÆ.

_Body more or less compressed, oblong or elevated, covered with small scales or naked; eye, lateral. Teeth, if present, conical. No bony stay for the præoperculum. The spinous dorsal is less developed than the soft or than the anal, either continuous with, or separated from, the soft portion; sometimes rudimentary. Ventrals thoracic, sometimes rudimentary or entirely absent. No prominent papilla near the vent. Gill-opening wide. Ten abdominal and fourteen caudal vertebræ._

Inhabitants of tropical and temperate seas. Carnivorous. They appear first in cretaceous formations, where they are represented by _Platax_ and some Caranx-like genera (_Vomer_ and _Aipichthys_ from the chalk of Comen in Istria). They are more numerous in various Tertiary formations, especially in the strata of Monte Bolca, where some still existing genera occur, as _Zanclus_, _Platax_, _Caranx_ (_Carangopsis_), _Argyriosus_ (_Vomer_), _Lichia_, _Trachynotus_. Of the extinct genera the following belong to this family:--_Pseudovomer_ (_Licata_), _Amphistium_, _Archæus_, _Ductor_, _Plionemus_ (?), and _Semiophorus_. _Equula_ has been recently discovered in the Miocene marls of Licata in Sicily.

CARANX (including _Trachurus_).--Body more or less compressed,
sometimes sub-cylindrical. Cleft of the mouth of moderate width.
The first dorsal fin continuous, with about eight feeble spines,
sometimes rudimentary; the soft dorsal and anal are succeeded
by finlets in a few species. Two anal spines, somewhat remote
from the fin. Scales very small. Lateral line with an anterior
curved, and a posterior straight, portion, either entirely or
posteriorly only covered by large plate-like scales, several
of which are generally keeled, the keel ending in a spine.
Dentition feeble. Air-bladder forked posteriorly.

The “Horse-mackerels” are found in abundance in almost all temperate and, especially, tropical seas. Many species wander to other parts of the coast, or to some distance from land, and have thus gradually extended their range over two or more oceanic areas; some are found in all tropical seas. The species described are very numerous, about ninety having been properly characterised and distinguished. Some attain to a length of three feet and more, and all are eatable. They feed on other fish and various marine animals.

Of the most noteworthy species the following may be mentioned:--_C. trachurus_, the common British Horse-mackerel, distinguished by having the lateral line in its whole length armed with large vertical plates; it is almost cosmopolitan within the temperate and tropical zones of the northern and southern hemispheres. _C. crumenophthalmus_, _C. carangus_, and _C. hippos_, three of the most common sea-fishes, equally abundant in the Atlantic and Indo-Pacific oceans; _C. ferdau_, from the Indo-Pacific, upwards of three feet in length. _C. armatus_, _ciliaris_, _gallus_, etc., which have an exceedingly short and compressed body, with rudimentary spinous dorsal fin, and with some of the rays of the dorsal and anal prolonged into filaments.

ARGYRIOSUS is closely allied to _Caranx_, especially to the
last-named species, but the lateral line has no plates whatever;
and the body is scaleless, chiefly of a bright silvery colour.

Two species from the tropical Atlantic.

MICROPTERYX.--Body much compressed, with prominent trenchant
abdomen, covered with small scales; lateral line not shielded;
præopercular margin entire. Cleft of the mouth rather small;
præorbital of moderate width. The first dorsal continuous, with
seven feeble spines. No detached finlets. Small teeth on the
vomer and palatine bones.

_Micropteryx chrysurus_ is a semi-pelagic fish, and very common in the tropical Atlantic, less so in the Indian Ocean.

SERIOLA.--Body oblong, slightly compressed, with rounded
abdomen, covered with very small scales; lateral line not
shielded; præopercular margin entire. Cleft of the mouth of
moderate width, or rather wide. The first dorsal continuous,
with feeble spines. No detached finlets. Villiform teeth in the
jaws, on the vomer and palatine bones.

These fishes are often called “Yellow-tails,” and occur in nearly all the temperate and tropical seas, sometimes at a great distance from land. Twelve species are known, and the majority have a wide geographical range. The larger grow to a length of from four to five feet, and are esteemed as food, especially at St. Helena, the Cape of Good Hope, in Japan, Australia, and New Zealand.

_Seriolella_ and _Seriolichthys_, the latter from the Indo-Pacific, and distinguished by a finlet behind the dorsal and anal, are allied genera.

NAUCRATES.--Body oblong, sub-cylindrical, covered with
small scales; a keel on each side of the tail. The spinous
dorsal consists of a few short free spines; finlets none.
Villiform teeth in the jaws, on the vomer and palatine bones.