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number; the scales are small or medium in size; and both the jaws, palatines, and
vomers bear villiform teeth. While the typical genus Curt us is confined to the
Indian seas, Pempheris ranges over the Indian Ocean, the Malayan seas, and the
tropical parts of the Pacific. The presence of a number of filaments, which may
attain an enormous length, is the most distinctive feature of the second family,



356 SPINY-PINNED GROUP.

as shown in the example of the type genus (Polynem/US plebejus), represented 011 the
left side of the illustration last referred to ; while a second characteristic is to be
found in the two rather short dorsal fins, situated at a considerable distance from one
another ; and a third in the well-marked mucous-bearing canals on the head. The
body is oblong and somewhat compressed, with smooth or slightly ciliated scales.
and a continuous lateral line. The muzzle projects somewhat beyond the mouth,
which is inferior in position, with a lateral cleft ; and the large eyes are lateral.
There are villiform teeth in the jaws and on the palate; and the pelvic fins are
thoracic in position, with one spine and five rays. These fishes, which form three
genera, include a number of species haunting the shores of tropical seas, and some-
times entering brackish or fresh water. Their filaments, which sometimes exceed
twice the entire length of the head and body and can be moved independently of
the pectoral fins, serve as feelers; and as these fish live in muddy water, and
generally have their large eyes obscured by a film, the use of such accessory organs
of touch is easily understood.

THE SOLENOIDS, Family

Of more general interest than the last is the family of Sciajnoids, among which
the umbrine of the Mediterranean and the widely distributed meagre are well known
examples. In this group the spinous dorsal is abbreviated at the expense of tl it-
more or less elongated soft dorsal, which also exceeds the anal fin in length : and,
although mucous canals are well developed on the head, there are no filaments
near the pectoral fin. The somewhat elongated and compressed body is coated
with ctenoid scales, and the uninterrupted lateral line sometimes continued on
to the tail-fin. The long mouth is at the extremity of the muzzle ; the eye is
medium and lateral; and in addition to bands of villiform teeth, the jaws may
carry tusks, although they are never provided with incisors or molars, and the
palate is devoid of teeth. The preopercular bone is smooth, and without any bony
connection with the orbit ; and the thoracic pelvic fins carry one spine and five*
rays. Frequently the air-bladder is j rovided with a number of appendages.
These fishes have a rather curious geographical distribution, being unknown in the-
Pacific and the Red Sea, but widely spread in the Atlantic and Indian Oceans, and
especially common round the shores of ' India, where many species enter estuaries
and rivers. Some species have, indeed, taken completely to fresh water, and never
by any chance descend to the sea. Nearly all are eaten as food, and the air-
bladders of many of the Indian forms are extensively used as a source of isinglass.
The North American fish, rejoicing in the name of " drum "
(Pogonias ckromis), represents a genus characterised by the upper
jaw of the convex muzzle overhanging the lower, the presence of numerous small
barbels on the chin, and the absence of tusks. Ten stout spines form the first
dorsal fin, and there are two spines in the anal, the hindmost of which is very-
strong. The scales are of moderate size ; and there are a number of large flattened'
molar-like teeth on the pliaryngcal bones. In length the drum often exceeds 4 feet; 1
while it may scale upwards of 1 cwt. In what manner the extraordinary drumming
sounds uttered by this fish, in common with other members of the family, are 1



SCI&NOIDS.



357



Umbrines.



produced, does not appear to be ascertained, although it lias been suggested that
they may be due to the clapping together of the upper and lower pharyngeal teeth.
The umbrine of the Mediterranean (Umbrina cirrkosa), whose
range extends southwards to the Cape, was a fish well known to the
ancients, and is a member of a genus containing about a score of species distributed
through the Mediterranean, Atlantic, and Indian Oceans. Having an overlapping
upper jaw, it differs from the last genus in the presence of but a single short
barbel on the chin ; while the first dorsal fin has ten flexible spines, and the anal
either one or two. In size the typical species reaches about 3 feet.

The third genus that we notice (Scicena) differs from both the
Meagres.

preceding in the absence of any barbels ; the cleft of the mouth being
oblique and deep, and the eyes situated rather wide apart. The genus includes a
very large number of species, with a geographical range equal to that of the family ;




.

of the best known being the typi. ^[ meagre (8. aquila), ranging from the
itish coasts to those of the Cape and Australia. Although most of the species
smaller, this fish may attain a length of upwards of 6 feet. Yarrell states that
e flesh of the meagre " appears always to have been in great request with
3picures ; and, as on account of its large size it was always sold in pieces, the
fishermen of Rome were in the habit of presenting the head, which was considered
the finest part, as a sort of tribute to the three local magistrates who acted for the
time as the conservators of the city." It is certain members of this genus that have
taken to a fresh-water existence.

THE SWORD-FISHES, Family XlPffllD^;.

With this small and well-defined family, all the members of which attain very
arge dimensions, we come to our first representatives of purely pelagic fishes,
'ufficiently distinguished from all their allies by the production of the upper jaw
ito the long, wedge-shaped, sword-like weapon from which they take their name,






358 SPINY-FINNED GROUP.

the sword-fishes are further characterised by the elongate and compressed body,
the laterally-placed eyes, and tlic deep cleft of the mouth. Teetli are either absent
or rudimentary ; and scales are likewise wanting, or represented merely by small
rudimental structures. The dorsal fin is either single or divided, but lias no
distinct spinous portion ; and the pelvis, if present at all, takes the form of long,
rod-like, thoracically-situated appendages. There are seven branchiostegal rays,
and an air-bladder is present. In the adult the sword is formed by the coalescence
of the premaxillas, vomer, and ethmoid, and is rough on the under surface from
the presence of rudimental teeth. The sword-fishes are divided into the genera
Xiphias and Histiophorus, according to the absence or presence of pelvic fins;
these appendages in the latter being in the form of from one to three rays. There
is considerable variation in the height of the dorsal fin, which is frequently so
lofty as to project some distance above the water when the fish is swimming near
the surface, and even, it is said, to answer the purpose of a sail. In the young,
this fin is much higher in proportion to the length of the body than it is in
the adult. In very young examples of the typical genus the beak is comparatively
long, there are conical prominences on the edge of the supraorbital, the occiput
is devoid of a spine, and there are two short, tooth-like processes at the angle of
the preopercular. In Histiophorus, on the other hand, the beak at a correspond inn-
age is much shorter; the supraorbital edge is finely denticulated, or smooth; and
there is a bony spine on each side of the occiput, and at the angle of the preopercular.
Although they are frequently not more than 4 to 6 feet in length, sword-fishes
may measure as much as from 12 to 15 feet, and the sword itself may exceed a
yard in length. The common European sword-fish (Xiphias gladius), which is
occasionally taken on the British coasts, ranges from the European seas to the
opposite side of the Atlantic; while to the southward it occurs off the northern
and western coasts of Africa. Histiopkorus, on the other hand, seems to be
confined to the Pacific and Indian Oceans, ranging eastwards to Japan. Of the
three Indian species, the spotted Indian sword-fish (H. gladius) is distinguished
by the dorsal fin being much higher than the body, and marked with dark blue
spots on a lighter ground of the same colour ; the body being bluish grey above,
and lighter beneath. On the other hand, in the black-finned sword-fish (H.
immaculatus) the general colour of the body is dull grey, and the dorsal and
anal fins are blackish. The third species (H. brevirostris) has the dorsal fin lower
than the depth of the body; the general colour being grey, but the dorsal and
pectoral fins tipped witli black.

Mainly pelagic in their habits, sword-fishes are among the most predaceoua
and savage of the monsters of the deep, transfixing their ordinary prey, which
includes cod and tunny, with their formidable sword, and likewise attacking
whales with the same weapon. In such conflicts, the sword-fish, after making
repeated stabs, generally comes out victorious, and the whale succumbs to his
comparatively diminutive antagonist. Occasionally, however, one of these fishes
appears to mistake a ship's bottom for a whale, and thereupon promptly charges
it, sending the sword crashing* through several inches of solid timber. In such
cases it may happen that the sword-fish cannot withdraw its weapon, which is
then broken off short in the struggles of its owner to escape. One thing we



SWO&D-FISHES.



359



should like to see cleared up by actual observation, and that is, in what manner
a sword-fish manages to remove from his weapon a cod, or other fish, which it
has spitted. Instances are on record of these fish attacking and transfixing
bathers ; one such having occurred in the estuary of the Severn about the year 1830.
Writing of one of the Pacific species, Colonel Pike observes that " this fish is a
beautiful sight in the water. It has a habit of lying sunning itself on the surface
when undisturbed, its dorsal fin is fully expanded and acting as a sail (and when
needed it can propel itself at great speed) ; but it is only in the calmest weather it
can be thus seen. It is frequently caught in deep water with hook and line, and
when near the surface it is speared." When it feels the hook, or spear, a sword-
fish takes tremendous leaps in the air, and if care be not exercised, will jump into




nat. size).

ie boat of the fishermen. In the South Sea Islands young sword-fish are caught
in strong nets, although no net will hold a fish of 6 feet in length. One of the
most recent instances of a sword-fish attacking a ship occurred in the year 1874,
on the voyage between Bombay and Calcutta. On this subject Frank Buckland
writes that there is in the Museum of the College of Surgeons a section of the
bow of a South-Sea whaler, in which " is seen the end of the sword of a sword-
fish, measuring 1 foot in length and 5 inches in circumference. At one single
blow the fish had lunged his sword through, and completely transfixed thirteen
and a half inches of solid timber. The sword had, of course, broken off in the
hole, and thus prevented a dangerous leak in the ship. In the British Museum is
a second specimen of a ship's side with the sword of a sword-fish fixed in it, and
which has penetrated no less than twenty-two inches into the timber. When His
Majesty's ship Leopard was repairing, in 1795, after her return from the coast of



360 Sl'INY-FINNED GROUP.

Guinea, a sword of one of these tislics was found to have gone through (In-
sheathing one inch, next through a three-inch plank, and beyond that four and a
half inches into the firm timber ; and it was the opinion of the mechanics that it
would require nine strokes of a twenty-five-pound hammer to drive a bolt of
similar size and form to the same depth into the same hull ; yet this was accom-
plished by a single thrust of the fish." In the Mediterranean countries, where
these fishes are commonly taken in tunny-nets, their flesh is exposed for sale in
the markets. Geologically, the sword-fishes appear to be a comparatively modern
group, the earliest known representatives, which have been assigned to the existing
genus Histiophorus, occurring in the London Clay.

THE SCABBARD-FISHES AXD HAIR-TAILS, Family TRICHIUPJD.J-:.

Another group of equal rank with the perch-like section is formed by a
family of fishes, characterised by the elongate and compressed or even band-like
form of the body; the mouth having a wide cleft, and several large conical teeth
either in the jaws or on the palate. The dorsal and anal rays are long and many-
rayed, with the spinous nearly equal in length to the soft portion, finlets some-
times occurring behind the latter ; the pelvic fins, if present, are thoracic in position ;
and the caudal is sometimes wanting, but, when developed, forked. In all cases
the scales are either rudimental or wanting, but the air-bladder is constant. These
fishes are distributed over all tropical and subtropical seas ; but while some are
surface-forms, never found at any great distance from the coasts, others descend
to considerable depths in the open sea; all are carnivorous, and many very
powerful. In India, writes Day, " these fishes are held in various estimation in
different places. In Baluchistan, and where salt is cheap, no one will touch them :
but along the coasts of India they are more esteemed, mostly because being thin
or ribbon-shaped they can be dried without salting. In a fossil state these fishes
date from the lower Eocene of Switzerland and other parts of Europe, where they
are represented by extinct genera; species of scabbard-fish occur in the Sicilian
Miocene, which has also yielded forms allied to the hair- tails (Trichiurichthys),
but with the body scaled.

Among the better-known forms, the scabbard-fish (Lepidopus
Scabbard-Fish.

caudatus) represents a genus characterised by the absence or rudi-
mentary condition of the pelvic fins, the long single dorsal, and the distinct
but small tail-fin. Although it may attain a length of 5 or 6 feet, the attenuation
of the body is so great that the whole weight does not exceed as many
pounds. The fish has a very wide geographical distribution, ranging from the
Mediterranean and warmer regions of the Atlantic to the Cape, and thence to
New Zealand and Tasmania, while it occasionally wanders to the British coasts.
This wide range may probably be taken as an indication that the scabbard-fish
is a comparatively deep-sea form. In New Zealand, where it is known as the
frost-fish, the scabbard-tish is highly esteemed for its flesh, which is white, rich,
firm, and tender, with an excellent flavour. On this account, says an anonymous
writer, "the fish is eagerly sought after, and commands a high price, as the supply
is irregular, and not equal to the demand. Not much is yet known of the manners



SCABBARD-FISHES AND HAIR-TAILS.



361



and customs of the frost-fish, but the little that lias been made manifest is decidedly
peculiar. It is a deep-water fish, and yet, strange to say, has never yet been
taken by the net, the rod, or the line. Even the all-gathering trawl has hitherto
failed to bring it to the surface of the deep. How then is its capture effected ?
To all appearance the frost-fish is captured by the fishermen only when it commits
suicide and immolates itself on the sandy beaches of the Pacific. The facts are,
that on calm and frosty nights, during the autumn and winter months, numbers
of IVost-fish come ashore alive through the surf on the beaches before referred to,
and there wriggle on to the firmer sands above, to be devoured by the watchful
sea-birds, or picked up by the fortunate fisherman. No satisfactory reason has
as yet been assigned for this rash act, although numerous theories have been





SCABBARD-I



>pounded to account for it. One is that the hapless fish is pursued by a shark
other enemy, and prefers uncertain life on land to certain death at sea.
Another and a more plausible theory is that the fish distends its air-bladder to
(nable it to reach the surface for air or food, and that the keen frosty air there
prevents it from compressing the bladder, and thus returning to its habitat under
the waves. In this way the luckless fish gradually drifts into shallow water, and
is dashed ashore by the surf, only to struggle on to dry land to meet its fate.
As may be imagined, the capture of the frost-fish has nothing specially sportsman-
like about it. The long sandy beaches some twelve miles from Dunedin are the
favourite resort of the frost-fisher. The usual plan is to form a party of two or
more, and camp out overnight at the foot of the cliffs which overhang the beach.
Here a huge fire is lighted, and a tent pitched close at hand. The night, of course,
must be clear and calm, as well as frosty, otherwise the long Pacific rollers make
the surf too high for the successful capture of the game. The fishing itself is
rather slow work. It consists merely in walking from end to end of the beach



362 SPINY-FINN ED GROUP.

shortly before dawn (the untimely hour chosen by the fish for self-destruction),
and keeping a sharp look-out in the surf for the silver streak which betokens the
advent of the frost-fish. When a fish is seen struggling in the waves or on
the sand, all that remains to be done is to catch hold of it, and drag it up out of
reach of the backwash (if it does not wriggle up by its own motion), and there
despatch it with a stick or knife."

These scaleless fish (Trichiurus) take their name from the
Hair-Tails

absence of a caudal fin, the body tapering posteriorly into a fine

point. The single dorsal extends the whole length of the ribbon-like body ;
the pelvic fins are represented merely by a pair of scales, or are completely
wanting; and the anal is rudimental, its spinous portion being reduced to a
number of very small spines scarcely projecting above the skin. The jaws are
provided with long tusks, and there are teeth on the palatine bones, although
none on the vomer. Essentially tropical fishes, generally found in the vicinity
of land, they appear to be sometimes carried by currents out to sea, which will
probably account for the occasional appearance of the West Indian T. lepturus on
the British coasts. These fishes attain a length of from 3 to 4 feet ; and one of
the Indian species is described as extremely voracious, preying on crustaceans and
various fishes, among which members of its own kind are included.

The local name for a New Zealand representative (Thyrsitea
Barracudas.

atun) of another genus may be taken as the popular title of all its

members. These fishes, in which the rather elongate body is covered with minute
scales, are characterised by having from two to six finlets behind the dorsal and
anal, and the presence of teeth on the palatines. Barracudas, which grow to as
much as 5 feet, form important food supplies in the Cape, South Australia, New
Zealand, and Chili ; when the flesh has been dried or otherwise preserved, it is
exported from New Zealand in quantities to Mauritius and Batavia. The genus
is unknown in the Indian seas, where the family is represented by the hair-tails.
Allied Extinct Two extinct genera, namely, Palceorhynchus from the Eocene of

Forms. Switzerland, and Heinirhynchus from the Oligocene of France, re-
present a separate family (Palceorhynchidce), distinguished from the last by the
production of the muzzle into a long beak, which may be either provided with
small teeth, or toothless. The dorsal fin occupies nearly the whole length of the
compressed body ; and the anal fin is also elongated, and extends nearly to
the forked caudal.

THE SURGEONS, Family AcnoNURiD^;.

With this family we come to a group of spiny-finned fishes, including some
thirteen others, which present the following characteristics in common. The dorsal
fins are either placed together or continuous, the spinous portion being, when fully
developed, shorter than the soft part, while it may be modified into tentacles,
detached spines, or an adhesive disc ; and the anal is similar in characters to the
soft dorsal, and in some instances both these fins are modified posteriorly into
finlets. The pelvic fins, if developed, are always thoracic or jugular in position,
and are never modified into a sucker ; and there are no papillae in the neighbour-
hood of the vent. Nearly the whole of the members of the group are marine.



HORSE-MACKERELS. 363

Tho first family is typified by a genus (Acronurus) the representatives
of which are, popularly known by the name of "surgeons," owing to the presence
of a sharp lancet-like spine on each side of the tail in the adult. In addition
to the presence of one or more such spines or bony plates, the family is further
characterised by a single dorsal fin, with a very small number of spines. The
body is compressed, and oblong or deep in form, with a covering of minute
scales ; the moderate-sized eyes are lateral in position ; the small mouth is
furnished in front with a single series of more or less compressed upper and
lower incisors, which may be either pointed or serrated ; but the palate is toothless.
The pelvic fins are thoracic in position, and the hinder extremity of the air-bladder
is forked. These fishes are inhabitants of all the tropical seas, and are most
common in the neighbourhood of coral-reefs and islands, where some feed on the
soft polyps of the coral, but others on various vegetable substances. In the true
surgeons (Acronurus) there is an erectile spine situated in a groove on each side
of the tail ; and the pelvic fins are generally furnished with a single spine and
five rays. In the young the body is scaleless, and the tail-spines either very small
or wanting. These fishes are represented by a large number of species, the largest
of which does not exceed 18 inches in length, and they are distributed over all
tropical seas with the exception of the Eastern Pacific., In a fossil state the genus,
like the next, occurs in the middle Eocene beds of Monte Bolca, in Italy. From
the true surgeons the members of the genus Naseus, which range over the Tropical
Pacific and the Indian Ocean, are distinguished by having from one to three non-
erectile spines on each side of the tail, and the presence of only three rays in the
ventral fins ; while in some forms the head is armed with a forwardly-directed
bony horn or crest-like prominence. The minute and rough scales make the skin
like fine shagreen. A third genus (Prionurus) differs in having a series of keeled
bony plates instead of spines on the sides of the tail. All the species of Naseus
are said to be purely herbivorous. The true surgeons use their spines as formid-
able weapons of attack by erecting them and striking sideways with their tails.

THE HORSE-MACKERELS, Family CARANGIVJE.

Although the name horse-mackerel properly applies only to a single British
fish (Caranx trachurus), otherwise known as the scad, it may conveniently be
made to do duty for the whole of the members of the family to which that species
pertains. Having the body more or less compressed, these fishes are specially
distinguished by the teeth, when present, being villiform or conical. The spinous
portion of the dorsal fin is sometimes rudiments!; the hinder rays of both the
dorsal and anal may be broken up into separate finlets ; and, when present, the
pelvic fins are thoracic in position. In the skeleton there are ten trunk,
and fourteen tail vertebrae; although in one genus the number of the latter is
increased to sixteen. The gill-openings are wide, the eyes lateral, and there is no
bony stay connecting the preopercular with the infraorbital ring. The scales,
which are usually small, may be altogether wanting ; and in many cases the lateral
line is wholly or partially armed with shield-like overlapping plates. There is
always an air-bladder. In the young of some forms there is an armature of the



N} '-FINNED G R O UP.



head, which disappears in the adult. Carnivorous in their diet, (lie horse-mackerela
are distributed at the, present day over all temperate and tropical seas; and were
also abundant during the Tertiary period, and likewise represented by extinct
genera in the antecedent Cretaceous epoch. Remains of these fishes are. found in
extraordinary profusion in the middle Eocene, strata of Monte .Bolca, one of the
most remarkable types from that formation being the extinct fiemiopfionia, in
which the dorsal fin is so elevated as to exceed the total length of the head and



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 38 of 62)