Chapter XXI: The Fishes of the Deep Sea (5)

The “Pilot-fish” (_N. ductor_) is a truly pelagic fish, known in all tropical and temperate seas. Its name is derived from its habit of keeping company with ships and large fish, especially Sharks. It is the _Pompilus_ of the ancients, who describe it as pointing out the way to dubious or embarrassed sailors, and as announcing the vicinity of land by its sudden disappearance. It was therefore regarded as a sacred fish. The connection between the Shark and the Pilot-fish has received various interpretations, some observers having perhaps added more sentiment than is warranted by the actual facts. It was stated that the Shark never seized the Pilot-fish, that the latter was of great use to its big companion in conducting it and showing it the way to its food. Dr. Meyen in his “Reise um die Erde” states: “The pilot swims constantly in front of the Shark; we ourselves have seen three instances in which the Shark was led by the Pilot. When the Shark neared the ship the Pilot swam close to the snout, or near one of the pectoral fins of the animal. Sometimes he darted rapidly forwards or sidewards as if looking for something, and constantly went back again to the Shark. When we threw overboard a piece of bacon fastened on a great hook, the Shark was about twenty paces from the ship. With the quickness of lightning the Pilot came up, smelt at the dainty, and instantly swam back again to the Shark, swimming many times round his snout and splashing, as if to give him exact information as to the bacon. The Shark now began to put himself in motion, the Pilot showing him the way, and in a moment he was fast upon the hook.[42] Upon a later occasion we observed two Pilots in sedulous attendance on a Blue Shark, which we caught in the Chinese Sea. It seems probable that the Pilot feeds on the Sharks’ excrements, keeps his company for that purpose, and directs his operations solely from this selfish view.” We believe that Dr. Meyen’s opinion, as expressed in his last words, is perfectly correct. The Pilot obtains a great part of his food directly from the Shark, in feeding on the parasitic crustaceans with which Sharks and other large fish are infested, and on the smaller pieces of flesh which are left unnoticed by the Shark when it tears its prey. The Pilot also, being a small fish, obtains greater security when in company of a Shark, which would keep at a distance all other fishes of prey that would be likely to prove dangerous to the Pilot. Therefore, in accompanying the Shark, the Pilot is led by the same instinct which makes it follow a ship. With regard to the statement that the Pilot itself is never attacked by the Shark all observers agree as to its truth; but this may be accounted for in the same way as the impunity of the swallow from the hawk, the Pilot-fish being too nimble for the unwieldy Shark.

The Pilot-fish does not always leave the vessels on their approach to land. In summer, when the temperature of the sea-water is several degrees above the average, Pilots will follow ships to the south coast of England into the harbour, where they are generally speedily caught. Pilot-fish attain a length of 12 inches only. When very young their appearance differs so much from the mature fish that they have been described as a distinct genus, _Nauclerus_. This fry is exceedingly common in the open ocean, and constantly obtained in the tow-net; therefore the Pilot-fish retains its pelagic habits also during the spawning season, and some of the spawn found by voyagers floating on the surface is, without doubt, derived from this species.

CHORINEMUS.--Body compressed, oblong; covered with small scales, singularly shaped, lanceolate, and hidden in the skin. The first dorsal is formed by free spines in small numbers; the posterior rays of the second dorsal and anal are detached finlets. Small teeth in the jaws, on the vomer and palatine bones.

Twelve species are known from the Atlantic and Indo-Pacific; some enter brackish water, whilst others are more numerous at some distance from the shore. They attain to a length of from 2 to 4 feet. In the young, which have been described as _Porthmeus_, the spines and finlets are connected by membrane with the rest of the fin.

_Lichia_ is an allied genus from the Mediterranean, tropical Atlantic, and the coast of Chili; five species.

TEMNODON.--Body oblong, compressed, covered with cycloid scales
of moderate size. Cleft of the mouth rather wide. Jaws with
a series of strong teeth; smaller ones on the vomer and the
palatine bones. The first dorsal with eight feeble spines
connected by membrane; finlets none. Lateral line not shielded.
The second dorsal and anal covered with very small scales.

_Temnodon saltator_, sometimes called “Skip-jack,” is spread over nearly all the tropical and sub-tropical seas; it frequents principally the coasts, but is also met with in the open sea. On the coasts of the United States it is well known by the name of “Blue-fish,” being highly esteemed as food, and furnishing excellent sport. It is one of the most rapacious fishes, destroying an immense number of other shore-fishes, and killing many more than they can devour. It grows to a length of 5 feet, but the majority of those brought to market are not half that length.

TRACHYNOTUS.--Body more or less elevated, compressed, covered
with very small scales. Cleft of the mouth rather small, with
short convex snout. Opercles entire. The first dorsal composed
of free spines in small number. No finlets. Teeth always small,
and generally lost with age.

Ten species are known from the tropical Atlantic and Indo-Pacific; they rarely exceed a length of 20 inches. Some of the most common marine fishes belong to this genus, for instance _T. ovatus_, which ranges over the entire tropical zone.

PAMMELAS (_perciformis_) is allied to the preceding genus; from the coast of New York.

PSETTUS.--Body much compressed and elevated; snout rather short.
One dorsal, entirely covered with scales, with seven or eight
spines; anal fin with three. Ventrals very small, rudimentary.
Teeth villiform; no teeth on the palate. Scales small, ctenoid.

Only three species are known; one, _P. sebæ_, from the west coast of Africa, the two others from the Indo-Pacific. _P. argenteus_ is a very common fish, attaining to a length of about 10 inches.

PLATAX.--Body much compressed and elevated; snout very short.
One dorsal, with the spinous portion nearly entirely hidden, and
formed by from three to seven spines; anal with three. Ventrals
well developed, with one spine and five rays. Teeth setiform,
with an outer series of rather larger teeth, notched at the top;
palate toothless. Scales of moderate size or rather small.

These fishes are called “Sea-bats,” from the extraordinary length of some portion of their dorsal and anal fins and of their ventrals. These long lobes are generally of a deep black colour. In mature and old individuals the fin-rays are much shorter than in the young, which have been described as distinct species. There are probably not more than seven species of “Sea-bats,” if so many, and they all belong to the Indian Ocean and Western Pacific, where they are very common.

ZANCLUS.--Body much compressed and elevated. One dorsal, with
seven spines, the third of which is very elongate. No teeth on
the palate. Scales minute, velvety.

One species (_Z. cornutus_), which is extremely common in the Indo-Pacific. It is easily recognised by its snout, which is produced like that of _Chelmon_, and by the broad black bands crossing the yellow ground-colour. It attains to a length of eight inches, and undergoes during growth similar changes as _Acanthurus_.

ANOMALOPS.--Body oblong, covered with small, rough scales. Snout
very short, convex, with wide cleft of the mouth. Eyes very
large; below the eye, in a cavity of the infraorbital ring,
there is a glandular phosphorescent organ. Villiform teeth in
the jaws and on the palatine bones, none on the vomer. First
dorsal fin short, with a few feeble spines connected by membrane.

This genus, of which one species only is known (_A. palpebratus_), represents the family of Horse-Mackerels in the depths of the sea; but we do not know, at present, at what depth it lives. Only six specimens have been obtained hitherto from the vicinity of Amboyna, the Fidji, and Paumotu Islands; the largest was twelve inches long.

CAPROS.--Body compressed and elevated. Mouth very protractile.
Scales rather small, spiny. First dorsal with nine spines, anal
with three. Ventral fins well developed. Minute teeth in the
jaws and on the vomer; none on the palatine bones.

The “Boar-fish” (_C. aper_) is common in the Mediterranean, and not rarely found on the south coast of England.

Allied are _Antigonia_ and _Diretmus_, known from a few individuals obtained at Madeira and Barbadoes; they are probably fishes which but rarely come to the surface.

EQUULA.--Body more or less compressed, elevated or oblong,
covered with small, deciduous, cycloid scales. Mouth very
protractile. Minute teeth in the jaws; none on the palate. One
dorsal. Formula of the fins: D. 8/1516, A. 3/14, V. 1/5. The
lower præopercular margin serrated.

Small species, abundant in the Indo-Pacific, disappearing on the coasts of Japan and Australia. Some eighteen species have been described.

_Gazza_ is very similar to _Equula_, but armed with canine teeth in the jaws.

Other genera referred to this family are _Lactarius_ (_L. delicatulus_, common, and eaten on the East Indian coasts), _Seriolella_, _Paropsis_, and _Platystethus_.

THIRD FAMILY--CYTTIDÆ.

_Body elevated, compressed, covered with small scales, or with bucklers, or naked; eye lateral. Teeth conical, small. No bony stay for the præoperculum. Dorsal fin composed of two distinct portions. Ventrals thoracic. No prominent papilla near the vent. Gill-opening wide. More than ten abdominal and more than fourteen caudal vertebræ._

The fishes of the “Dory” family are truly marine, and inhabit the temperate zone of the Northern and Southern Hemispheres. Some fossils from tertiary formations (one from Licata) belong to the genus Zeus.

ZEUS.--A series of bony plates runs along the base of the dorsal
and anal fins; another series on the abdomen. Three or four anal
spines.

“John Dorys” are found in the Mediterranean, on the eastern temperate shores of the Atlantic, on the coasts of Japan and Australia. Six species are known, all of which are highly esteemed for the table. The English name given to one of the European species (_Zeus faber_) seems to be partly a corruption of the Gascon “Jau,” which signifies cock, “Dory” being derived from the French Dorée, so that the entire name means Gilt-Cock. Indeed, in some other localities of Southern Europe it bears the name of _Gallo_. The same species occurs also on the coasts of South Australia and New Zealand. The fishermen of Roman Catholic countries hold this fish in special respect, as they recognise in a black round spot on its side the mark left by the thumb of St. Peter when he took the piece of money from its mouth.

CYTTUS.--Body covered with very small scales; no osseous
bucklers on any part of the body. Two anal spines; ventral fins
composed of one spine and six or eight rays.

Three species are known from Madeira, South Australia, and New Zealand.

FOURTH FAMILY--STROMATEIDÆ.

_Body more or less oblong and compressed, covered with very small scales; eye lateral. Dentition very feeble; œsophagus armed with numerous horny, barbed processes. No bony stay for the præoperculum. Dorsal fin single, long, without distinct spinous division. More than ten abdominal and more than fourteen caudal vertebræ._

This small family consists of strictly marine and partly pelagic species referred to two genera, _Stromateus_ and _Centrolophus_. The former lacks ventral fins, at least in the adult stage, and is represented by about ten species in almost all the tropical and warmer seas. _Centrolophus_, hitherto known from two or three European species only (of which one occasionally reaches the south coast of England, where it is named “Black-fish”), has recently been discovered on the coast of Peru, and has probably a much wider range.

FIFTH FAMILY--CORYPHÆNIDÆ.

_Body compressed; eye lateral. Teeth small, conical, if present; œsophagus smooth. No bony stay for the præoperculum. Dorsal fin single, long, without distinct spinous division. More than ten abdominal and more than fourteen caudal vertebræ._

All the members of this family have pelagic habits. Representatives of it have been recognized in some fossil remains: thus _Goniognathus_ from the Isle of Sheppey, and the living genus _Mene_ (_Gastrocnemus_) at Monte Bolca.

CORYPHÆNA.--Body compressed, rather elongate; adult specimens
with a high crest on the top of the head; cleft of the mouth
wide. A single dorsal extending from the occiput almost to the
caudal, which is deeply forked; no distinct dorsal and anal
spines. The ventrals are well developed, and can be received
in a groove on the abdomen. Scales very small. Rasp-like teeth
in the jaws, on the vomer and the palatine bones. Air-bladder
absent.

Generally, though by misapplication of the name, called “Dolphins.” About six species are known, each of which is probably distributed over all the tropical and sub-tropical seas. Strictly pelagic in their habits, they are most powerful swimmers; they congregate in shoals, and pursue unceasingly the Flying-Fish, which try to escape their enemies by long flying leaps. They attain to a length of six feet, and are eagerly caught by sailors on account of their well-flavoured flesh. The beauty of their, unfortunately fugitive, colours has ever been a subject of admiration. As far as the colours are capable of description, those of the common species (_C. hippurus_), which is often seen in the Mediterranean, are silvery blue above, with markings of a deeper azure, and reflections of pure gold, the lower parts being lemon-yellow, marked with pale blue. The pectoral fins are partly lead colour, partly yellow; the anal is yellow, the iris of the eye golden. These iridescent colours change rapidly whilst the fish is dying, as in the Mackerel. The form of the body, and especially of the head, changes considerably with age. Very young specimens, from one to six inches in length, are abundant in the open sea, and frequently obtained in the tow-net. Their body is cylindrical, their head as broad as high, and the eye relatively very large, much longer than the snout. As the fish grows the body is more compressed, and finally a high crest is developed on the head, and the anterior part of the dorsal fin attains a height equal to that of the body.

BRAMA.--Body compressed, and more or less elevated, covered with
rather small scales; cleft of the mouth very oblique, with the
lower jaw longest. Dorsal and anal fins many-rayed, the former
with three or four, the latter with two or three, spines; caudal
deeply forked. Ventrals thoracic, with one spine and five rays.
The jaws with an outer series of stronger teeth.

Pelagic fishes which, like the allied genus _Taractes_, range over almost all the tropical and temperate seas.

LAMPRIS.--Body compressed and elevated, covered with very small
deciduous scales; cleft of the mouth narrow. A single dorsal,
without a spinous portion. Ventrals composed of numerous rays.
Teeth none.

The “Sun-fish” (_L. luna_) is one of the most beautiful fishes of the Atlantic. It attains to the large size of four feet in length, is bluish on the back, with round silvery spots, which colour prevails on the lower parts; the fins are of a deep scarlet. It is said to be excellent eating. It is a pelagic fish, not rare about Madeira, but extending far northwards in the Atlantic; it seems to be rarer in the Mediterranean. All the specimens hitherto obtained were full-grown or nearly so. The skeleton exhibits several peculiarities, viz. an extraordinary development and dilatation of the humeral arch, and great strength of the numerous and closely-set ribs.

Other Coryphænoid genera are _Pteraclis_, _Schedophilus_, _Diana_, _Ausonia_, and _Mene_; all pelagic forms.

SIXTH FAMILY--NOMEIDÆ.

_Body oblong, more or less compressed, covered with cycloid scales of moderate size; eye lateral. No bony stay for the præoperculum. Dorsal fin with a distinct spinous portion separated from the soft; sometimes finlets; caudal forked. More than ten abdominal, and more than fourteen caudal vertebræ._

Marine fishes; pelagic, at least when young.

GASTROCHISMA.--Cleft of the mouth wide. Finlets behind the
dorsal and anal fins. The ventral fins are exceedingly broad
and long, and can be completely concealed in a fold of the
abdomen.

_G. melampus_, from the coast of New Zealand; scarce.

NOMEUS.--Cleft of the mouth narrow. No finlets. The ventral fin
is long and broad, attached to the abdomen by a membrane, and
can be received in a fissure of the abdomen.

_N. gronovii_ is a common pelagic fish in the Atlantic and Indian Oceans; of small size.

Other genera belonging to this family are _Psenes_ and _Cubiceps_.

SEVENTH FAMILY--SCOMBRIDÆ.

_Body oblong, scarcely compressed, naked or covered with small scales; eye lateral. Dentition well developed. No bony stay for the præoperculum. Two dorsal fins; generally finlets. Ventrals thoracic, with one spine and five rays. More than ten abdominal, and more than fourteen caudal vertebræ._

The fishes of the “Mackerel” family are pelagic forms, abundant in all the seas of the tropical and temperate zones. They are one of the four families of fishes which are the most useful to man, the others being the Gadoids, Clupeoids, and Salmonoids. They are fishes of prey, and unceasingly active, their power of endurance in swimming being equal to the rapidity of their motions. Their muscles receive a greater supply of blood-vessels and nerves than in other fishes, and are of a red colour, and more like those of birds or mammals. This energy of muscular action causes the temperature of their blood to be several degrees higher than in other fishes. They wander about in shoals, spawn in the open sea, but periodically approach the shore, probably in the pursuit of other fishes on which they feed.[43]

_Scombridæ_ are well represented in tertiary formations: in the Eocene schists of Glaris two extinct genera, _Palimphyes_ and _Isurus_, have been discovered. In Eocene and Miocene formations _Scomber_, _Thynnus_, and _Cybium_ are not uncommon.

SCOMBER.--The first dorsal continuous, with feeble spines; five
or six finlets behind the dorsal and anal. Scales very small,
and equally covering the whole body. Teeth small. Two short
ridges on each side of the caudal fin.

Mackerels proper are found in almost all temperate and tropical seas, with the exception of the Atlantic shores of temperate South America, where they have not been found hitherto. In Europe, and probably also on the coast of England, three species occur: _S. scomber_, the common Mackerel, which lacks an air-bladder; _S. pneumatophorus_, a more southern species, with an air-bladder; and _S. colias_, like the former, but with a somewhat different coloration, and often called “Spanish” Mackerel. On the Cape of Good Hope, in Japan, on the coast of California, in South Australia, and New Zealand, Mackerels are abundant, which are either identical with, or very closely allied to, the European species. On the coasts of the United States the same species occur which tenant the western parts of the Atlantic. Altogether seven species are known.

THYNNUS.--The first dorsal continuous, with the spines rather
feeble; from six to nine finlets behind the dorsal and anal.
Scales of the pectoral region crowded, forming a corslet. Teeth
rather small. A longitudinal keel on each side of the tail.

The best-known species of this genus is the “Tunny” (_Thynnus thynnus_), abundant in the Mediterranean, and ranging to the south coast of England and to Tasmania. It is one of the largest fishes of the ocean, attaining to a length of 10 feet, and to a weight of more than 1000 lbs. The fishery of the Tunny is systematically carried on in the Mediterranean, and dates from the most remote antiquity. Its salted preparation was esteemed by the Romans under the name of _Saltamentum sardicum_. Its flesh is extensively eaten now, fresh as well as preserved.

_Thynnus pelamys_, or the “Bonito,” is equally well known, and ranges over all the tropical and temperate seas; it eagerly pursues the Flying-fish, and affords welcome sport and food to the sailor. In its form it resembles the Tunny, but is more slender and rarely above three feet long.

Some of the other species are provided with very long pectoral fins, and generally called by sailors “Albacore.” They are said to grow to a length of six feet; Bennett in his “Whaling Voyage,” vol. ii. p. 278, makes the following observations on _Th. germo_, from the Pacific: “Ships when cruising slowly in the Pacific Ocean, are usually attended by myriads of this fish for many successive months. A few days’ rapid sailing is, nevertheless, sufficient to get rid of them, however numerous they may be, for they seldom pay more than very transient visits to vessels making a quick passage. When the ship is sailing with a fresh breeze they swim pertinaciously by her side and take the hook greedily, but should she be lying motionless or becalmed they go off to some distance in search of prey, and cannot be prevailed upon to take the most tempting bait the sailor can devise. It is probably as a protection from their chief enemy, the Sword-fish, that they seek the society of a ship. I am not aware that the Shark is also their enemy; but they seemed to have an instinctive dread of this large fish, and when it approached the ship, would follow it in shoals, and annoy it in the same manner as the smaller birds may be seen to annoy those of a larger and predaceous kind, as the hawk or owl. They are very voracious and miscellaneous feeders. Flying-fish, Calmars, and small shoal-fish are their most natural food; though they do not refuse the animal offal from a ship. Amongst the other food contained in their maw, we have found small Ostracions, File-fish, Sucking-fish, Janthina shells, and pelagic crabs; in one instance a small Bonita, and in a second a Dolphin eight inches long, and a Paper-nautilus shell containing its sepia-tenant. It was often amusing to watch an Albacore pursuing a Flying-fish, and to mark the precision with which it swam beneath the feeble æronaut, keeping him steadily in view, and preparing to seize him at the moment of his descent. But this the Flying-fish would often elude by instantaneously renewing his leap, and not unfrequently escape by extreme agility.”

PELAMYS.--The first dorsal continuous, with the spines rather
feeble; from seven to nine finlets behind the dorsal and
anal. Scales of the pectoral region forming a corslet. Teeth
moderately strong. A longitudinal keel on each side of the tail.

Five species are known, of which _P. sarda_ is common in the Atlantic and Mediterranean.

AUXIS.--Differing from the preceding two genera in having very
small teeth in the jaws only, none on the palate.

_Auxis rochei_ common in the Atlantic, Mediterranean, and Indian Ocean.

CYBIUM.--The first dorsal continuous, with the spines rather
feeble; generally more than seven finlets behind the dorsal and
anal. Scales rudimentary or absent. Teeth strong; a longitudinal
keel on each side of the tail.

Twelve species from the tropical Atlantic and Indian Ocean; frequenting more the coast-region than the open sea; attaining to a length of four or five feet.

ELACATE.--Body covered with very small scales; head depressed;
cleft of the mouth moderately wide; no keel on the tail. The
spinous dorsal is formed by eight small free spines; finlets
none. Villiform teeth in the jaws, on the vomer and the palatine
bones.

_Elacate nigra_, a coast fish common in the warmer parts of the Atlantic and the Indian Ocean.

ECHENEIS.--The spinous dorsal fin is modified into an adhesive
disk, occupying the upper side of the head and neck.

This genus is closely allied to the preceding, from which it differs only by the transformation of the spinous dorsal fin into a sucking organ. The spines being composed of two halves, each half is bent down towards the right and the left, forming a support to a double series of transverse lamellæ, rough on their edges, the whole disk being of an oval shape and surrounded by a membranous fringe. Each pair of lamellæ is formed out of one spine, which, as usual, is supported at the base by an interneural spine. By means of this disk the “Sucking-fishes” or “Suckers” are enabled to attach themselves to any flat surface, a series of vacuums being created by the erection of the usually recumbent lamellæ. The adhesion is so strong that the fish can only be dislodged with difficulty, unless it is pushed forward by a sliding motion. The Suckers attach themselves to sharks, turtles, ships, or any other object which serves their purpose. They cannot be regarded as parasites, inasmuch as they obtain their food independently of their host. Being bad swimmers they allow themselves to be carried about by other animals or vessels endowed with a greater power of locomotion. They were as well known to the ancients as they are to the modern navigators. Aristotle and Aelian mention the Sucker under the name of φθεὶρ, or the _Louse_; “In the sea between Cyrene and Egypt there is a fish about the Dolphin (_Delphinus_), which they call the Louse; this becomes the fattest of all fishes, because it partakes of the plentiful supply of food captured by the Dolphin.” Later writers, then, repeat a story, the source of which is unknown, viz. that the “Remora” is able to arrest vessels in their course, a story which has been handed down to our own time. It need not be stated that this is an invention, though it cannot be denied that the attachment of one of the larger species may retard the progress of a sailing vessel, especially when, as is sometimes the case, several individuals accompany the same ship. An account of a somewhat ingenious way of catching sleeping turtles by means of a Sucking-fish held by a ring fastened round its tail, appears to have originated rather from an experiment than from regular practice.

Ten different species are known, of which _Echeneis remora_ and _Echeneis naucrates_ are the most common. The former is short and grows to a length of eight inches only, the latter is a slender fish, not rarely found three feet long. The bulkiest is _Echeneis scutata_, which attains to a length of two feet; individuals of that size weighing about eight lbs.

The number of pairs of lamellæ varies in the various species, from 12 to 27. The caudal fin of some of the species undergoes great changes with age. In young specimens the middle portion of the fin is produced into a long filiform lobe. This lobe becomes gradually shorter, and the fin shows a rounded margin in individuals of middle age. When the fish approaches the mature state, the upper and lower lobes are produced, and the fin becomes subcrescentic or forked.

[See Günther, “On the History of Echeneis.” Ann. and Mag. Nat.
Hist., 1860.]

EIGHTH FAMILY.--TRACHINIDÆ.

_Body elongate, low, naked or covered with scales. Teeth small, conical. No bony stay for the præoperculum. One or two dorsal fins, the spinous portion being always shorter and much less developed than the soft; the anal similarly developed as the soft dorsal; no finlets. Ventrals with one spine and five rays. Gill-opening more or less wide. Ten or more than ten abdominal, and more than fourteen caudal vertebræ._

Carnivorous coast-fishes of small size, found in every quarter of the globe, but scarcely represented in the Arctic zone (_Trichodon_); on the other hand, they are rather numerous towards the Antarctic circle. All are bad swimmers, generally moving along the bottom in small depths. Only one genus (_Bathydraco_) is known from the deep-sea.

A genus which shows the principal characters of this family (_Callipteryx_), has been found in the tertiary deposits of Monte Bolca; it is scaleless. A second genus, _Trachinopsis_, has been recently described by Sauvage from the Upper Tertiary of Lorca in Spain; and a third (_Pseudoeleginus_) from the Miocene of Licata.

This family may be subdivided into five groups:--

1. In the URANOSCOPINA the eyes are on the upper surface of the
head, directed upwards; the lateral line is continuous.

URANOSCOPUS.--Head large, broad, thick, partly covered with bony
plates; cleft of the mouth vertical. Scales very small. Two
dorsal fins, the first with from three to five spines; ventrals
jugular; pectoral rays branched. Villiform teeth in the jaws,
on the vomer and palatine bones; no canines. Generally a long
filament below and before the tongue. Gill-cover armed.

The position of the eyes on the upper surface of the head, which these fishes have in common with many others, is well expressed by the name _Uranoscopus_ (Stare-gazer). Their eyes are very small, and can be raised or depressed at the will of the fish. They are inactive fishes, generally lying hidden at the bottom between stones, watching for their prey. The delicate filament attached to the bottom of their mouth, and playing in front of it in the current of water which passes through the mouth, serves to lure small animals within reach of the fish. Eleven species are known from the Indo-Pacific and Atlantic, and one (_U. scaber_) from the Mediterranean; they attain rarely a length of twelve inches.

LEPTOSCOPUS.--Form of the head as in _Uranoscopus_, but entirely
covered with a thin skin. Scales small, cycloid. One continuous
dorsal; ventrals jugular; pectoral rays branched. Villiform
teeth in both jaws, on the vomer and palatine bones; canines
none. No oral filament. Gill-cover unarmed.

_Leptoscopus macropygus_, not rare on the coast of New Zealand.

Other genera of Stare-gazers are _Agnus_ from the Atlantic coasts of North America; _Anema_ from the Indian Ocean and New Zealand; and _Kathetostoma_ from Australia and New Zealand.

2. In the TRACHININA the eyes are more or less lateral; the
lateral line is continuous; and the intermaxillary without a
larger tooth on its posterior portion.

TRACHINUS.--Cleft of the mouth very oblique; eye lateral, but
directed upwards. Scales very small, cycloid. Two dorsal fins,
the first short, with six or seven spines; ventrals jugular; the
lower pectoral rays simple. Villiform teeth in the jaws, on the
vomer and palatine bones. Præorbital and præoperculum armed.

The “Weevers” are common fishes on the European coasts, and but too well known to all fishermen; singularly enough they do not extend across the Atlantic to the American coast, but reappear on the coast of Chili! Wounds by their dorsal and opercular spines are much dreaded, being extremely painful, and sometimes causing violent inflammation of the wounded part. No special poison-organ has been found in these fishes, but there is no doubt that the mucous secretion in the vicinity of the spines has poisonous properties. The dorsal spines as well as the opercular spine have a deep double groove in which the poisonous fluid is lodged, and by which it is inoculated in the punctured wound. On the British coasts two species occur, _T. draco_, the Greater Weever, attaining to a length of twelve inches, and _T. vipera_, the Lesser Weever, which grows only to half that size.

CHAMPSODON.--Body covered with minute granular scales; lateral
lines two, with numerous vertical branches. Cleft of the mouth
wide, oblique. Eye lateral, but directed upwards. Two dorsal
fins; ventral fins jugular; pectoral rays branched. Teeth in the
jaws in a single series, thin, long, of unequal size. Teeth on
the vomer, none on the palate. Gill-openings exceedingly wide.
Præoperculum with a spine at the angle and a fine serrature on
the posterior margin.

_Champsodon vorax_ is not uncommon at small depths off the Philippine Islands, Admiralty Islands, and in the Arafura Sea.

PERCIS.--Body cylindrical, with small ctenoid scales; cleft of
the mouth slightly oblique; eye lateral, but directed upwards.
Dorsal fins more or less continuous, the spinous with four or
five short stiff spines; ventrals a little before the pectorals.
Villiform teeth in the jaws, with the addition of canines; teeth
on the vomer, none on the palatines. Opercles feebly armed.

Fifteen species; small, but prettily coloured shore-fishes of the Indo-Pacific.

SILLAGO.--Body covered with rather small, ctenoid scales.
Cleft of the mouth small, with the upper jaw rather longer;
eye lateral, large. Two dorsals, the first with from nine
to twelve spines; ventrals thoracic. Villiform teeth in the
jaws, and on the vomer, none on the palatine bones. Operculum
unarmed; præoperculum serrated. The bones of the head with wide
muciferous channels.

Eight species; small, plain-coloured shore-fishes, common in the Indian Ocean to the coasts of Australia.

BOVICHTHYS.--Head broad and thick; cleft of the mouth
horizontal, with the upper jaw rather longer; eye lateral, more
or less directed upwards. Scales none. Two separate dorsal
fins, the first with eight spines; ventrals jugular; the lower
pectoral rays simple. Villiform teeth in the jaws, on the vomer
and the palatine bones; no canines. Operculum with a strong
spine; præorbital and præoperculum not armed.

Three species are known from the South Pacific.

BATHYDRACO.--Body elongate, sub-cylindrical; head depressed,
with the snout much elongate, spatulate; mouth wide, horizontal,
with the lower jaw prominent; eyes very large, lateral, close
together. Scales very small, imbedded in the skin. Lateral line
wide, continuous. One dorsal fin; ventrals jugular; the lower
pectoral rays branched. Teeth in the jaws in villiform bands;
none on the vomer or the palatine bones. Opercles unarmed; ten
branchiostegals; the gill-membranes free from the isthmus, and
but slightly united in front. Air-bladder none.

A deep-sea fish, found at a depth of 1260 fathoms in the Antarctic Ocean (south of Heard Island).

CHÆNICHTHYS.--Head very large, with the snout spatulate, and
with the cleft of the mouth very wide. Eye lateral. Scales none;
lateral line sometimes with granulated scutes. Two dorsals, the
first with seven spines; ventrals jugular. Jaws with rasp-like
teeth; palate toothless.

_Chænichthys rhinoceratus_ from Kerguelen’s Land (see Fig. 108, p. 291); and _Ch. esox_ from the Straits of Magelhaen.

Other genera belonging to this group are _Aphritis_, _Acanthaphritis_, _Eleginus_, _Chænichthys_, and _Chimarrhichthys_ from the South Pacific and Antarctic zone; _Cottoperca_ from the west coast of Patagonia; _Percophis_ from the coast of Southern Brazil; and _Trichodon_ from the coast of Kamtschatka.

3. In the PINGUIPEDINA the body is covered with small scales;
the eye lateral; the lateral line continuous; and the
intermaxillary is armed with a larger tooth on its posterior
portion, as in many Labroids.

Two genera, _Pinguipes_ and _Latilus_, from various parts of tropical and sub-tropical seas, belong to this group.

4. In the PSEUDOCHROMIDES, the lateral line is interrupted or
not continued to the caudal fin; they have one continuous dorsal
only.

These fishes are inhabitants of coral reefs or coasts: _Opisthognathus_, _Pseudochromis_, _Cichlops_, and _Pseudoplesiops_.

5. In the NOTOTHENIINA the lateral line is interrupted;
and the dorsal fin consists of two separate portions.

They (with others) represent in the Antarctic zone the Cottoids of the Northern Hemisphere: they have the same habits as their northern analogues. In _Notothenia_, which on the southern extremity of South America, in New Zealand, Kerguelen’s Land, etc., is represented by about twenty species, the body is covered with ctenoid scales, and the bones of the head are unarmed; whilst _Harpagifer_, a small species with a similar range as _Notothenia_, has the body naked, and the operculum and sub-operculum armed with long and strong spines.

NINTH FAMILY--MALACANTHIDÆ.

_Body elongate, with very small scales; mouth with thick lips; a strong tooth posteriorly on the intermaxillary. Dorsal and anal fins very long, the former with a few simple rays anteriorly; ventrals thoracic, with one spine and five rays. Gill-opening wide, with the gill-membranes united below the throat. Ten abdominal and fourteen caudal vertebræ._

One genus only, _Malacanthus_, with three species from tropical seas.

TENTH FAMILY--BATRACHIDÆ.

_Head broad and thick; body elongate, compressed behind; skin naked or with small scales. No bony stay for the præoperculum. Teeth conical, small or of moderate size. The spinous dorsal consists of two or three spines only; the soft and the anal long. Ventrals jugular, with two soft rays; pectorals not pediculated. Gill-opening a more or less vertical slit before the pectoral, rather narrow._

Carnivorous fishes, of small size, living on the bottom of the sea near the coast in the tropical zone, some species advancing into the warmer parts of the temperate zones.

BATRACHUS.--The spinous dorsal is formed by three stout spines.
Gill-covers armed with spines. Circumference of the mouth and
other parts of the head frequently provided with small skinny
tentacles.

Some of the fishes of this genus possess a subcutaneous spacious cavity behind the base of the pectoral fin, the inside of which is coated with a reticulated mucous membrane. It opens by a foramen in the upper part of the axil.--This apparatus is the same which is found in many Siluroid fishes, and which has been noticed above, p. 192. There cannot be any doubt that it is a secretory organ, but whether the secretion has any poisonous properties, as in the Siluroids, or as in _Thalassophryne_, has not been determined. No instance of poisonous wounds having been inflicted by these fishes is on record. Twelve species are known, the distribution of which coincides with that of the family; one very fine species, _B. didactylus_, occurs in the Mediterranean.

THALASSOPHRYNE.--The spinous dorsal is formed by two spines
only, each of which is hollow, like the opercular spine, and
conveys the contents of a poison-bag situated at its base.
Canine teeth none.

Two species are known from the Atlantic and Pacific coasts of Central America. The poison-apparatus is more perfectly developed than any other known at present in the class of fishes; it has been described above, p. 192. The species figured, _Th. reticulata_, is not uncommon at Panama, and attains to a length of fifteen inches.

PORICHTHYS.--Two small dorsal spines; a canine tooth on each
side of the vomer.

Two species, from the Atlantic and Pacific sides of Central and South America.

ELEVENTH FAMILY--PSYCHROLUTIDÆ.

_Body rather elongate, naked; head broad. Spinous dorsal separate or absent. Ventral fins close together, thoracic, composed of a few rays. Teeth small. Three gills and a half; pseudobranchiæ well developed; gill-openings of moderate width, the gill-membranes being attached to the isthmus._

Of this family only two representatives are known, viz. _Psychrolutes paradoxus_, from Vancouver’s Islands, without first dorsal fin; and _Neophrynichthys latus_, from New Zealand, with two dorsal fins. Both are very scarce marine fishes.

TWELFTH FAMILY--PEDICULATI.

_Head and anterior part of the body very large, without scales. No bony stay for the præoperculum. Teeth villiform or rasp-like. The spinous dorsal is advanced forwards, composed of a few more or less isolated spines, often transformed into tentacles; or entirely absent. Ventral fins jugular, with four or five soft rays, sometimes absent. The carpal bones are prolonged, forming a sort of arm, terminating in the pectoral. Gill-opening reduced to a small foramen, situated in or near the axil. Gills two and a half, or three, or three and a half; pseudobranchiæ generally absent._

This family contains a larger number of bizarre forms than any other; and there is, perhaps, none in which the singular organisation of the fish is more distinctly seen to be in consonance with its habits. Pediculates are found in all seas. The habits of all are equally sluggish and inactive; they are very bad swimmers; those found near the coasts lie on the bottom of the sea, holding on with their arm-like pectoral fins by seaweed or stones, between which they are hidden; those of pelagic habits attach themselves to floating seaweed or other objects, and are at the mercy of wind and current. A large proportion of the genera, therefore, have gradually found their way to the greatest depths of the ocean; retaining all the characteristics of their surface-ancestors, but assuming the modifications by which they are enabled to live in abyssal depths.

LOPHIUS.--Head exceedingly large, broad, depressed, with the
eyes on its upper surface; cleft of the mouth very wide. Jaws
and palate armed with rasp-like depressible teeth of unequal
size. Body naked; bones of the head armed with numerous spines.
The three anterior dorsal spines are isolated, situated on the
head, and modified into long tentacles; the three following
spines form a continuous fin; the soft dorsal and anal short.
Gills three. Young individuals have the tentacles beset with
lappets, and most of the fin-rays prolonged into filaments.

These fishes are well known under the names “Fishing-Frog,” “Frog-fishes,” “Anglers,” or “Sea-devils.” They are coast-fishes, living at very small depths. Four species are known: the British species (_L. piscatorius_) found all round the coasts of Europe and Western North America, and on the Cape of Good Hope; a second (Mediterranean) species, _L. budegassa_; _L. setigerus_ from China and Japan; and _L. naresii_ from the Admiralty Islands.

The habits of all these species are identical. The wide mouth extends all round the anterior circumference of the head, and both jaws are armed with bands of long pointed teeth, which are inclined inwards, and can be depressed so as to offer no impediment to an object gliding towards the stomach, but prevent its escape from the mouth. The pectoral and ventral fins are so articulated as to perform the functions of teeth, the fish being enabled to move, or rather to walk, on the bottom of the sea, where it generally hides itself in the sand, or amongst seaweed. All round its head, and also along the body, the skin bears fringed appendages, resembling short fronds of seaweed; a structure which, combined with the extraordinary faculty of assimilating the colours of the body to its surroundings, assists this fish greatly in concealing itself in places which it selects on account of the abundance of prey. To render the organisation of these creatures perfect in relation to their wants, they are provided with three long filaments inserted along the middle of the head, which are, in fact, the detached and modified three first spines of the anterior dorsal fin. The filaments most important in the economy of the fishing-frogs is the first, which is the longest, terminates in a lappet, and is movable in every direction. There is no doubt that the Fishing-frog, like many other fish provided with similar appendages, plays with this filament as with a bait, attracting fishes, which, when sufficiently near, are ingulfed by the simple act of the Fishing-frog opening its gape. Its stomach is distensible in an extraordinary degree, and not rarely fishes have been taken out of it quite as large and heavy as their destroyer. The British species grows to a length of more than five feet; specimens of three feet are common. Baird records that the spawn of the same species has been observed as a floating sheet of mucus, of from some 60 to 100 square feet.

CERATIAS.--Head and body much compressed and elevated; cleft
of the mouth wide, subvertical. Eyes very small. Teeth in the
jaws rasp-like, depressible; palate toothless. Skin covered
with numerous prickles. The spinous dorsal is reduced to two
long isolated spines, the first on the middle of the head, the
second on the back. The soft dorsal and anal short; caudal very
long. Ventrals none; pectorals very short. Two and a half gills.
Skeleton soft and fibrous.

_Ceratias holbölli_, a deep-sea fish; only a few examples have been found near the coast of Greenland, and from the mid-Atlantic; the latter at a depth of 2400 fathoms. Deep black.

HIMANTOLOPHUS.--Head and body compressed and elevated; cleft
of the mouth wide, oblique. Eyes very small. Teeth of the jaws
rasp-like, depressible; palate toothless. Skin with scattered
conical tubercles. The spinous dorsal is reduced to a single
tentacle on the head. The soft dorsal, anal, caudal, and
pectoral short. Ventrals none. Three and a half gills. Skeleton
soft and fibrous.

This is another deep-sea form, hitherto found in very few examples in the Arctic and Mid-Atlantic Oceans. The single tentacle is beset with many long filaments at its extremity, thus answering the same purpose which is attained by a greater number of tentacles. Deep black.

MELANOCETUS.--Head and body compressed; head very large; cleft
of the mouth exceedingly wide, vertical. Eyes very small. Teeth
of the jaws and vomer rasp-like, depressible. Skin smooth. The
spinous dorsal is reduced to a single filament placed on the
head. The soft dorsal and anal short. Ventrals none.

Two species are known from the Atlantic: _M. bispinossus_ and _M. johnsonii_, obtained at depths of from 360 to 1800 fathoms. The specimen figured was not quite four inches long, and contained in its stomach, rolled up spirally into a ball, a Scopeline fish which measured 7½ inches in length and one inch in depth.

ONEIRODES.--A deep-sea fish from the Arctic Ocean, differing
from the preceding in possessing a second isolated dorsal ray on
the back.

ANTENNARIUS.--Head very large, high, compressed; cleft of the
mouth vertical or subvertical, of moderate width. Jaws and
palate armed with rasp-like teeth. Eye small. Body naked or
covered with minute spines; generally with tentacles. The
spinous dorsal is reduced to three isolated spines, the anterior
of which is modified into a tentacle, situated above the snout.
The soft dorsal of moderate length; anal short. Ventrals present.

The fishes of this genus are pelagic, frequently met with in mid-ocean between the tropics, especially in parts of the sea with floating vegetation; not rarely individuals are found far from their native latitudes, carried by currents to the coasts of Norway and New Zealand. Their power of swimming is most imperfect. When near the coast they conceal themselves between corals, stones, or fucus, holding on to the ground by means of their arm-like pectoral fins. Their coloration is so similar to their surroundings that it is hardly possible to distinguish the fish from a stone or coral overgrown with vegetation. Their way of attracting and seizing their prey is evidently the same as in the other fishes of this family. The extraordinary range of some of the species which inhabit the Atlantic as well as the Indo-Pacific Oceans, is the consequence of their habit of attaching themselves to floating objects. Almost all the species are highly coloured, but the pattern of the various colours varies exceedingly. These fishes do not attain to any considerable size, and probably never exceed a length of ten inches. A great number of species have been distinguished by ichthyologists, but probably not more than twenty are known at present. The species figured on p. 295 (_A. caudomaculatus_) is common in the Red Sea, and probably occurs in other parts of the Indian Ocean.

_Brachionichthys_ and _Saccarius_ are allied genera from South Australia, Tasmania, and New Zealand.

CHAUNAX.--Head very large, depressed; cleft of the mouth wide,
subvertical; eye small; rasp-like teeth in the jaws and palate.
Skin covered with minute spines. The spinous dorsal is reduced
to a small tentacle above the snout; the soft dorsal of moderate
length; anal short; ventrals present.

A deep-sea fish (_Ch. pictus_), of uniform pink colour; hitherto found near Madeira and the Fidji Islands, at a depth of 215 fathoms.

MALTHE.--Anterior portion of the body very broad and depressed.
The anterior part of the snout is produced into a more or less
prominent process, beneath which there is a tentacle retractile
into a cavity. Jaws and palate with villiform teeth. Skin with
numerous conical protuberances. Soft dorsal fin and anal very
short. Gill-opening superiorly in the axil; gills two and a half.

Although the rostral tentacle is situated at the lower side of the projection of the snout, it must be regarded as the homologue of a dorsal spine. In some of the preceding genera, _Oneirodes_ and _Chaunax_, the first dorsal spine is so far advanced on the snout as to come into connection with the intermaxillary processes; and the position of the rostral tentacle in _Malthe_ is only a still more advanced step towards the same special purpose for which the first dorsal spine is used in this family, viz. for the purpose of obtaining food. In _Malthe_ it is obviously an organ of touch. This genus belongs to the American shores of the Atlantic; _M. vespertilio_ being a tropical, _M. cubifrons_ a northern species.

HALIEUTÆA.--Head exceedingly large, depressed, nearly circular
in its circumference. Cleft of the mouth wide, horizontal.
Jaws with small rasp-like teeth; palate smooth. Forehead
with a transverse bony bridge, beneath which is a tentacle
(rostral spine) retractile into a cavity. Body and head covered
with small stellate spines. Soft dorsal and anal very short.
Gill-opening superiorly in the axil; gills two and a half.

A coast-fish (_H. stellata_) from China and Japan. Frequently found dry in Chinese insect-boxes.

This genus appears to be represented in the Atlantic Ocean by _Halieutichthys_ from Cuba, and by _Dibranchus_, dredged at a depth of 360 fathoms off the coast of West Africa; the latter genus possesses two gills only. Another genus, covered with large scattered tubercles, _Aegæonichthys_, has recently been described from New Zealand.

THIRTEENTH FAMILY--COTTIDÆ.

_Form of the body oblong, sub-cylindrical. Cleft of the mouth lateral. Dentition feeble, generally in villiform bands. Some bones of the head are armed; and a bony stay connects the præopercular spine with the infraorbital ring. Two dorsal fins (rarely one), the spinous being less developed than the soft and than the anal. Ventrals thoracic, with five or less soft rays._

The fishes of this family are of small size, bad swimmers, and generally living on the bottom, near the coasts, of almost all the arctic, temperate, and tropical seas. Only a few live in fresh water. They prefer shallow to deep water; and there is only one instance known of a member of this family living at a great depth, viz. _Cottus bathybius_ from the Japanese sea, which is stated to have been dredged in a depth of 565 fathoms. Fossil representatives are few in number: two or three species of _Trigla_; others, although having a general resemblance to the genus _Cottus_, were covered with ctenoid scales, and therefore are referred to a distinct genus, _Lepidocottus_; they are from tertiary formations.

COTTUS.--Head broad, depressed, rounded in front; body
sub-cylindrical, compressed posteriorly. Scaleless; lateral line
present. Pectoral rounded, with some or all the rays simple.
Jaws and vomer with villiform teeth; palatine teeth none.

The “Bull-heads” or “Miller’s Thumbs” are small fishes from the shores and fresh waters of the northern temperate zone. Some forty species are known; the greater number live in the northern half of the temperate zone. On the shore, as well as in rivers, they prefer rocky or stony to muddy ground, lying concealed between the stones, and watching for their prey, which consists of small crustaceans and other aquatic animals. The common British Miller’s Thumb (_C. gobio_) is found in almost all suitable fresh waters of Northern and Central Europe, especially in small streams, and extends into Northern Asia. Other freshwater species abound in North America and Northern Asia. _Cottus scorpius_ and _C. bubalis_, the common European marine species, range across the Atlantic to the American coasts. The male is said to construct a nest, for the reception of the spawn, of seaweeds and stones, and to anxiously watch and defend his offspring. The spine at the angle of the præoperculum, which is simple in the majority of the freshwater species, is frequently armed with accessory processes, and antler-like, in marine.

CANTRIDERMICHTHYS differs from _Cottus_ in having teeth on the
palatine bones.

Eleven species are known, distributed like _Cottus_, but absent in Europe and North-western Asia.

ICELUS.--Head large, armed at the gill-covers and on the neck;
body with a dorsal series of bony plates from the neck to
the base of the caudal; lateral line with osseous tubercles;
scattered scales on the sides and abdomen. Ventrals thoracic,
with less than five rays. No pectoral filaments. Villiform teeth
in the jaws, on the vomer and palatine bones.

Represents Cottus in the far north; _I. hamatus_ is common in Spitzbergen and Greenland, and has been found in abundance in lat. 81° 44’.

PLATYCEPHALUS.--Head broad, much depressed, more or less armed
with spines; body depressed behind the head, sub-cylindrical
towards the tail, covered with ctenoid scales. Two dorsal fins;
the first spine isolated from the others. Ventrals thoracic,
but rather remote from the base of the pectorals. Villiform
teeth in the jaws, on the vomer and palatine bones.

About forty species are known, of which some attain a length of two feet. This genus represents in the tropical Indian Ocean the _Cotti_ of the Arctic, and the _Nototheniæ_ of the Antarctic zone. Like these, they live on the bottom in shallow water, hidden in the sand, the colours of which are assimilated by those of their body. Therefore, they are very scarce near coral islands which are surrounded by great depths; whilst the number of species is rather considerable on many points of the shelving Australian coasts. Their long and strong ventral fins are of great use to them in locomotion. _P. insidiator_ is one of the most common Indian and Australian fishes, and readily recognised by two oblique black bands on the upper and lower caudal lobes.

HOPLICHTHYS, similar to _Platycephalus_, but with the back and
sides of the body covered with bony spiny plates. No separate
dorsal spine.

One species, _H. langsdorffii_, is common on the coast of Japan, and frequently placed dry by the Chinese into their insect-boxes.

TRIGLA.--Head parallelopiped, with the upper surface and the
sides entirely bony, the enlarged infraorbital covering the
cheek.

Two dorsal fins. Three free pectoral rays. Villiform teeth. Air-bladder generally with lateral muscles, often divided into two lateral halves. The species may be referred to three groups:--

1. Palatine teeth none; scales exceedingly small, except those
of the lateral line: _Trigla_.

2. Palatine teeth none; scales of moderate size: _Lepidotrigla_.

3. Palatine teeth present: _Prionotus_.