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Family LYCOVIL&.

This unimportant family, for which there is no proper English name,
includes small littoral fishes much resembling blennies in general appearance, and
mostly characteristic of high latitudes, although a few occur within the Tropics.
As a family they are characterised by the confluence of the median tins: by the



COD TRIBE. 43I

pelvic fins, if present at all, being of small size, jugular in position, and attached
to the pectoral arch; while the gill-opening is narrow, and the gill-membrane
attached to w r hat is known as the isthmus, that is to say, the space on the chest
intervening between the two branches of the lower jaw and the gill-openings. In
the typical genus, of which a species (Lycodes murcena) is represented in our
illustration, the elongated body is either naked or covered with minute scales
embedded in the skin ; the lateral line is more or less indistinct ; the eyes are of
medium size; and the lower jaw is overlapped by the upper. The small and
rudimentary pelvic fins are formed of a few rays ; conical teeth are present not
only in the jaw T s, but likewise on the palatines and vomer; the gill-opening is
narrow; and there is neither a barbel nor an air-bladder. While the majority
of the species (among which is our figured example) are from the Arctic seas a few
are found in the seas surrounding the Antarctic extremity of South America. In
Spitzbergen and off Behring Island the eel-like lycodes is taken at depths of from




nat. size).



350 to 500 fathoms. In the allied genus Gymnelis, which is of especial interest
from a geographical point of view on account of one species inhabiting the seas
around Greenland, while the second comes from the Straits of Magellan, there
are no pelvic fins, and the two jaws are of equal length. A third genus, Uronectes,
from Baffin Bay, agrees with the last in the absence of pelvic fins, but differs in
that the lower jaw is the longer. Three other genera are respectively represented
by species from Panama, Australia, and the Straits of Magellan.

THE COD TEIBE. Family GADID^.

Equalled only in this respect by the mackerels, flat-fish, salmon, and herrings,
the cod tribe form a family of the utmost importance from a commercial point of
view, and therefore demand a somewhat detailed notice. They are specially
characterised by the pelvic fins being generally composed of several rays ; and
by the caudal being either free, or, if united with the median fins, by the first



432



SO FT- FINNED GROUP.



dorsal being divided into two moieties. More or less elongate and subcyclindrical
in form, the body is covered with small cycloid scales ; there are either one, two,
or three dorsal fins, occupying nearly the entire length of the back, the rays of
the hindmost being well developed ; the anal is either single or divided ; and the
jugular pelvic fins are usually formed of several rays, but if reduced to filaments
there is always a double dorsal. The gill-opening is wide, and the gill-membrane in




HADDOCK, WHITING, AND



most instances not attached to the isthmus ; while if false gills are present at all
they are either glandular or rudimental. As a rule, there is an air-bladder.
Mostly marine, the members of the cod family are mainly characteristic of the
Arctic and Temperate seas, where they are comparatively shallow-water fishes.
There are, however, a certain number of deep-water types among the family, and
these have a much more extensive distribution, some of them occurring in the
tropical Indian seas. The fresh-water forms are limited to two or three. Although
the flesh of the cod tribe is by no means remarkable for its delicacy or flavour,



COD TRIBE.



433



it affords a most wholesome and substantial food, and as it possesses the property
of taking salt readily, it is more valuable as a food-supply than would otherwise
be the case. Moreover, the liver of the cod is of especial value as the source of a
highly strengthening medicinal oil, greatly increasing the value of the fishery
of this species, which affords employment to a host of men on both sides of the
Atlantic. The family is divided into more than twenty distinct genera, but in
this work our attention will be chiefly concentrated on those containing species of
commercial importance. Geologically the group is not a very ancient one, the
oldest known forms, all of which are referred to extinct genera, occurring in
the London Clay and other deposits of lower Eocene age.

The common cod (Gadus morrhua), of which a half -grown and
an adult example are shown in the two lower figures of our illustra-
tion, is the typical representative of a genus primarily characterised by the
presence of three dorsal and two anal fins, and of teeth on the vomer, the palatine
bones being toothless. The degree of elongation of the body is moderate, and the
narrow pelvic fins include six or more rays. In the majority of the eighteen species
recognised by naturalists there is a single barbel dependent from the chin, but in
some forms this is absent. The species are distributed over the Arctic and Tem-
perate regions of the Northern Hemisphere. The common cod belongs to a group of
several species characterised by the upper jaw r being the longer, and the outer series
of upper teeth stouter than the inner ones ; its barbel is relatively long. Cod
from the British seas and German Ocean are usually greenish or brownish olive in
colour, with a number of yellowish or brown spots ; but more to the north darker,
and often uniformly coloured specimens are more common, while in the race from
Greenland, Scandinavia, and Northern Norway there is frequently a large, irregular
black patch on each side of the body. As a rule, cod vary in length from 2 to 4
feet, and may weigh as much as 100 Ibs. ; but a specimen out of condition, caught
near Wick in the year 1872, measured upwards of 4| feet. The range of the cod
includes the coasts of Northern Europe, Iceland, and Greenland, whence it descends
on the American coast as far as the latitude of New York ; the depth at which the
fish is found extending as low as one hundred and twenty fathoms. In Britain
the spawning-time is in January, at which season these fish resort to the shores in
great numbers, although at other times of the year they are only found in the
neighbourhood of land singly. In America cod do not deposit their spawn till May.
The great fisheries are those of the Dogger Bank in the North Sea, Iceland, and
the banks of Newfoundland ; the product of the latter area having been formerly
the greatest of all, its average value some twenty years ago being estimated at
upwards of 700,000, of which 400,000 was accounted for by the dried fish alone,
the remainder being made up by the oil, skins, etc. The cod is an exceeding pro-
ductive fish, Buckland stating that the number of eggs in a roe weighing 7| Ibs.
was close on seven millions. Cod feed on various crustaceans, worms, molluscs,
and small fish ; and since they always frequent comparatively deep water, they
are caught by means of lines.

Belonging to the same group of the genus as the common cod,

the haddock (G. ceylejmus), which is shown in the left upper figure

of the illustration on p. 432, may be always recognised by the blackish patch on

VOL. V. 28



434 SOFT-FINNED GROUP.

each side of the body above the pectoral fin, and the black lateral line. Generally
haddock vary in weight from i to 4 Ibs., but in northern seas they attain a
larger size than further south, and measure as much as a yard in length. In
England the largest haddock are taken in winter, when they resort to the coast
for the purpose of spawning. They generally associate in large shoals; and in
stormy weather seek shelter in deep water among seaweeds, when it is useless to
attempt fishing for them. In addition to crustaceans and other invertebrates, their
food comprises small fishes of various kinds. Haddock are largely consul m-d
when split, dried, and smoked. They range across the Atlantic.

By far the most delicately flavoured British representatives of
Other Species. . . f

the genus is the whiting (67. merlangus), shown in the right upper

corner of the illustration on p. 432, which differs from all the preceding species in
the absence of a barbel on the chin, and is specially distinguished by a black spot
near the root of each pectoral fin. The usual weight is about 1^ Ibs. ; 4 Ibs.
being nearly the maximum attained. The distributional area of the whiting is
restricted to the seas of Northern Europe, where it is found in vast shoals ;
Plymouth being one of the British localities where these fish occur in great
abundance. Very shy in its habits, the whiting is a voracious fish, Yarrell stating
that several sprats have been taken from the stomach of one, while in another of
4 Ibs. weight were found four full-grown pilchards. The same writer states that
it appears to prefer sandy banks, but frequently shifts its ground in pursuit of
the fry of various other fishes on which it chiefly feeds. Next to the mackerel,
the whiting suffers more by transport than any British sea-fish, and should be
eaten as soon as possible after capture. Another species with a black spot near
the pectoral fin is the pout, or whiting-pout (G. luscus), which may be at once
distinguished from the whiting by the barbel on the chin, and the greater depth
of the body, which during life is marked with dark crossbands. Seldom exceed-
ing 5 Ibs. in weight, this fish ranges from Scandinavia to the Mediterranean, but
does not cross the Atlantic. The name of pout is derived from the power
possessed by this fish of inflating the membranes covering the eyes and adjacent
regions into a bladder-like form. Nearly allied is the much smaller power-cod
(G. minutus), which seldom exceeds half a dozen inches in length, and may be
further distinguished by the smaller proportionate depth of the body. Found in
vast shoals in the Baltic, the power-cod, although of little or no value, is always
welcomed as the harbinger of the advent of its larger cousins. The pollack, or
whiting-pollack (G. pollachius), is a British representative of the group in which
the lower jaw is the longer, and all the upper teeth are of equal size ; it has a dark
spot near the pectoral fin, but no barbel. This fish is an inhabitant of European
seas as far as the western portions of the Mediterranean. Haunting rocky
ground, pollack are famous for their power of withstanding strong tides and
currents ; they are very common in many parts of the south coast of England,
ns Devonshire, but become scarcer to the north. Being free biters, they afford
good sport with the line. The coal-fish (G. virens) is a closely allied but some-
what larger form, more northern in its distribution, and taking its name from the
black colour it frequently assumes. This fish is very common in the Baltic and
other northern seas, numbers being captured in the Orkneys. The largest



COD- TRIBE.



435



specimen on record appears to be one mentioned by Buckland, which measured
just over 3i feet in length, and scaled 25 Ibs.

Before referring to this species it may be mentioned that a deep-
sea cod (Halargyreus), which has been taken off Madeira and New
Zealand, belongs to a small group characterised by having two dorsal and two anal
fins. On the other hand, the hake (Merluccius vulgar-is) is the British representa-
tive of a germs belonging to a much larger group, characterised by having two
dorsals, a single anal, and a separate caudal fin. As a genus, the hakes are dis-
tinguished by the strong development of the pelvic fins, which are broad at the
base, as well as by the presence of strong teeth on the jaws and vorner, and the
absence of a barbel. The common hake is found on both sides of the North
Atlantic and other European seas ; and is represented in the colder seas of South
America, as well as in those of New Zealand, by the allied M. gayi. The hakes are
peculiar in having the transverse processes of some of the trunk-vertebrae ex-
panded and inflated, so as to form a kind of roof over the air-bladder. In size the
common hake is a rather large fish, reaching 2 or even 3 feet in length. On the
Cornish coasts, which they frequent in numbers in pursuit of the shoals of
pilchards, hake have been taken in vast quantities, upwards of forty thousand
having once been landed in a day at Mount's Bay, while on another occasion eleven
hundred were taken in two nights by a single boat. When captured in the
pilchard-nets, these fish generally gorge themselves to such an extent on their
fellow-captives as to become completely helpless. Although the flesh is coarse and
of inferior flavour, large numbers of hake are dried and salted.

As an example of a fresh- water representative of the cod family,
Burbot. .

we may refer to the well-known burbot or eel-pout (Lota vulgaris),

which is the sole member of its genus, and is common in the rivers of Central and
Northern Europe and North America. Belonging to the group with two dorsals,
one anal, and a distinct caudal, the genus Lota has the first dorsal fin well
developed, with from ten to thirteen rays, the pelvics with several rays, the head
flattened, the body much elongated, and villiforin teeth in the jaws and on the
vomer. The chin is furnished with a barbel. In length the burbot exceeds a yard,
and its flesh ranks high among fresh-water fish. Its form is shown in the upper-
most figure of the illustration on p. 436. In Britain found only in the east
of England, where it is not uncommon in the Cain and the Ouse, the burbot is
widely distributed on the Continent, frequenting alike large rivers, small streams,
lakes, and pools. It prefers, however, deep to shallow water, being found in large
lakes at a depth of from thirty to forty fathoms ; its colour being then paler than is
the case with specimens from shallower water. From its habit of lying concealed
beneath stones or in holes on the river bank, the burbot in some parts of England
is known as the coney-fish. Its food consists of the fry of other fishes, or the
adults of the smaller kinds ; and it is stated to be particularly destructive to the
perch. In the spawning-season, which varies considerably according to localities,
burbot are in the habit of congregating in large numbers ; and in some of the
German rivers masses of these fishes, including as many as a hundred individuals,
may be found knotted together after the fashion of eels. While some burbot
spawn in November and December, in others the function is delayed till March ;



43 6



SO FT- FINNED GROUP.



and it is during the spawning- season that the fish is in the best condition for the
table. The burbot is a fish of slow growth, not attaining full maturity till it is
upwards of four years old.

Ling and Rock- Distinguished from the burbot by the presence of several enlarge*
lings. teeth in the lower jaw and on the vomer, the ling (Molva vulgar!*)
may be regarded merely as a marine representative of that genus. The common




BURBOT AND wELs, immature (J nat. size).

ling, which generally measures from 2 to 3 feet in length, is a northern form,
ranging from the coasts of Greenland and Iceland to those of Britain and other
parts of Northern Europe. In this fish the upper jaw is the longer, but the
reverse condition obtains in a second Scandinavian species, and also in a third from
the Mediterranean, which are the only other representatives of the genus. The
ling-fishery is an important industry, large quantities of these fish being cured
and dried. Belonging to the same group of the family as the ling, the rocklmgs
(Motella) are readily distinguished by the reduction of the first of the two dorsal



CA VE-FISIJ. 437

fins to a narrow-rayed fringe, with the first ray elongated, more or less completely
received in a longitudinal groove. There is a band of teeth in the jaws, and another
on the vomer, arid all the species have barbels, not only on the chin, but likewise
on the muzzle, the number of these appendages affording the readiest means of
specific discrimination. They are all of small size, and while ranging over the
same seas as the ling, likewise extend to those of Japan, the Cape, and New
Zealand. The British representatives of the genus include the five -bearded
rockling (M. mustela), with four upper barbels, the four-bearded rockling (M.
cunbria}, and the common three-bearded rockling (M. tricirrhata) ; the little fish
commonly known as the mackerel-midge, and formerly regarded as the representa-
tive of a distinct genus being only the young of the rocklings.

Brief mention may be made here of a fish from the Northern, Temperate, and
Arctic seas, known as the torsk (Brosmius brosme), on account of its forming the
sole representative of a group characterised by having only a single long dorsal
and a shorter single anal fin, the caudal being distinct, the narrow pectorals formed
of five rays, teeth present 011 the vomer and palatines, as well as in the jaws, and
the chin furnished with a barbel. Attaining a length of a little over 20 inches
the torsk is occasionally taken in the Firth of Forth, and is abundant round the
Shetlands and Orkneys.

SAND-EELS AND THEIR ALLIES, Family OPHIDIID^.

In this rather small family, almost all the members of which are marine, the
pelvic fins, if developed at all, are rudimentary ; there is no separate anterior dorsal
or anterior anal, and the caudal is generally confluent with the median fins. In
form the body is more or less elongate, but it may be either naked or scaled.
The dorsal fin occupies the greater portion of the back ; the rudimentary pel vies
are jugular in position ; the gill-openings are wide ; and the gill-membranes are not
ittached to the isthmus. While some of these fishes are deep-sea forms, others are
littoral. The family may be divided into five subfamily groups.

The most remarkable representatives of the first subfamily (in
which pelvic fins, attached to the pectoral girdle, are always present)
ire two small fishes from the subterranean fresh waters of certain caves in Cuba,
)nstituting the genus Lucifuga. They are totally blind, with the eyes rudi-
lental and covered with skin, or wanting, and always live in perpetual darkness.
?he cave-fish are closely allied to certain small fishes from the Tropical Atlantic
and Indian Oceans forming the genus Brotula, and characterised by the elongate
body being covered with minute scales, the moderate-sized eyes, the reduction of
each pelvic fin to a single filament, of which the extremity may be split, the
villiforrn teeth, and the presence of barbels on the muzzle; these barbels being
reduced in the cave-fish to small tubercles. With the exception of these cave-
fish, all the members of this family are marine forms ; and it is very curious that
among the latter there are two very rare species, respectively constituting the
genera Typhlonus and Aphyonus, found at great depths in the southern oceans,
which are also completely blind, and apparently unprovided with any phosphorescent
organs.



438



SOFT-PINNED GROUP.



Snake-Fishes.



Parasitic Fish.



The typical genus < >i>I</<l in in, constituting, with an allied form,
the (second subfamily, has the pelvic fins replaced by a pair of barbel-
like filaments; the elongated and compressed body being covered with very
minute scales, while the eyes are medium, and the teeth small. The few species of
this genus range over the Atlantic and Pacific. In the South American, South
African, and Australasian seas there occur three much larger but nearly allied fishes,
which have been referred to a second genus (Genypterua), on account of the outer
row of teeth in the jaws, as well as those of the single palatine series, containing
some enlarged tusks. These fish are of considerable commercial importance, and are
known at the Cape as klipvisck, and in New Zealand as Cloudy Bay cod, or ling.

Some half-score species of very small eel-like fishes, scientifically
known as Fierasfer and Encheliophis, and inhabiting the Mediter-
ranean, Atlantic, and Indo-Pacific, have an especial interest on account of their

curious mode of life. They
constitute a subfamily, readily
characterised by the total
absence of pelvic fins and by
the vent being situated at the
throat; and are parasitic in
other marine animals, fre-
quenting the hollows in the
bodies of jelly - fish, the
breathing-chambers of star-
fishes and sea-cucumbers, and
sometimes insinuating them-
selves between the layers of
the mantle of pearl-mussels
or other bivalve molluscs.
Occasionally they may become
embedded in the substance of the shell of the pearl-mussel by the deposition of
pearly matter over their bodies ; an instance of this peculiar mode of preservation
being shown in the accompanying illustration,

The third subfamily is represented by the well-known sand-eels or
launces of which a British species (Ammodytes tobianus) is figured
in the illustration so abundant on sandy shores in Europe and North America,
as well as by an allied genus from Madras. While agreeing with the preceding
group in the want of pelvic fins, they differ in having the vent situated far back
in the body ; and are further characterised by the great width of the gill-openings,
the gill-membranes of opposite sides not being united. The lower jaw exceeds tin-
upper in length, the dorsal fin occupies nearly the whole length of the back, and
the anal is likewise elongated. The figured species, which is by far the commoner
on the British coasts, generally measures from 5 to 7 inches in length, whereas the
greater sand-eel (A. lanceolafn*} may grow to a foot and a half. Sand-eels feed
on marine worms and very small fish; and when buried in the sand are captured
in some parts of England by raking the sand with a long-pronged rake: their
chief use being for bait. They are, however, by no means restricted to this kind




PARASITIC FISH EMBEDDED IN A PEARL-MUSSEL.

(From Gunther, Proc. Zool. Soc., 1886.)



Sand-Eels.



LONG- TAILS AND FLAT-FISHES.



439



of lii'e, frequently swimming near the surface in large shoals, when they will at
times suddenly descend to the bottom, where they bury themselves with surpris-
ing rapidity by the aid of the elongated horn-like extremity of the elongated lower
jaw. During ebb-tide, numbers remain buried at the depth of five or six inches in




LESSER SAND-EEL (-?- nat. size).

the sand till the next flood ; and it is then that they are dug out with rakes or
other implements. When swimming, they are followed by shoals of mackerel
and porpoises.

The last group of the family is represented by Conyrodus of the
Australian coasts, and Haliophis from the Red Sea, both of which
differ from the sand-eels by the narrower gill-openings, and the union of the two
gill-membranes beneath the throat.



Conyrodus.






THE LONG-TAILS, Family

The fourth family of the symmetrically formed soft-finned fishes is typically
represented by the genus Macrurus, as well as by several allied forms. These fish
are characterised by the body ending in a long, compressed, and tapering tail, covered
with spiny, keeled, or striated scales, and unprovided with an expanded fin. There
is a separate short first dorsal fin, followed, after a short interval, by a very long
and low second dorsal, which is composed of very weak rays, and is continued to
the end of the tail ; the anal occupying a precisely similar position on the under
surface, and the thoracic or jugular pelvic fins consisting of several rays. Dr.
Giinther writes that " this family, known a few years ago from a limited number
of examples, representing a few species only, proves to be one which is distributed
over all oceans, occurring in considerable variety and great abundance at depths of
from one hundred and twenty to two thousand six hundred fathoms. They are, in
fact, deep-sea gadoids, much resembling each other in the general shape of the body,
but differing in the form of the snout, and in the structure of their scales. About

O

forty species are known, many of which attain a length of 3 feet."

THE FLAT-FISHES, Family PLEURONECTID^:.

Distinguished by the unsymmetrical conformation of the head and anterior
region of the body in the adult, in consequence of which both eyes are brought on



440 SO FT- FINNED GROUP.

to ono .side of the body (in some cases the right, and in others the left), the flat-
fishes differ not only from all other members of their class, hut likewise from all
other vertebrates. The body is strongly compressed and flattened, with the side
which is turned up \vards, and on which are situated the eyes, coloured dark, while



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 46 of 62)