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along the middle line of the symmetrical tail-fin.



PERCH TRIBE. 335

Physoclystous group are distinguished by the general absence of a duct to the
air-bladder (when present), by the parietal bones of the roof of the skull being
always separated from one another by the intervention of the supraoccipital, and
by the pelvic fins being in most cases either thoracic or jugular 1 in position.
Ilegarding, however, the spine-fmned fishes as constituting a separate suborder,
they are distinguished, in addition to the foregoing characters, by some of the
anterior rays of the dorsal, anal, and pelvic fins usually taking the form of strong,
unjointed, bony spines. It must, however, be acknowledged that this character is
one of but little importance; some of the hair- tails (Trichiuridce) scarcely possess-
ing what can be denominated true spines, while these are also wanting in the
family (Scombresocidcv) to which the flying-fishes belong. In ail cases the gills
are comb-like, the pectoral arch is suspended from the skull, and interclavicles
are wanting.

THE PERCH TRIBE, Family PERCID&

The first representatives of the spine-finned fishes are the perches, which, with
several allied families, belong to a sectional group (Perciformes) of the suborder,
characterised by the lower pharyngeal bones being generally separate, and the
scales usually of the ctenoid type. The preopercular bone of the gill-cover has no
bony stay connecting it with the eye ; the spinous portion of the dorsal fin is well
developed ; none of the additional rib-like bones known as epipleura are attached
to the bodies of the vertebrae ; the pelvic fins are thoracic in position, and have
usually five (rarely four) branched rays ; and the supporting bones (pterygials) of
the pectoral fins are longer than broad, and of a more or less distinctly hour-glass
form. The perch family, as restricted by Mr. Boulenger, is distinguished by the
following characters. In the skeleton the anterior vertebrae have no transverse
processes, but in the dorsal part of the series all or most of the ribs are attached
to such processes. There are two nostrils on each side ; the gill-membranes are free
from the isthmus, or space between the two branches of the lower jaw and gill-
openings ; there are four pairs of gills, with a slit behind the fourth ; the gill-rays,
or branchiostegals, vary from six to eight on each side ; more or less fully-
developed false gills are generally present ; the soft portion of the dorsal fin is not
very much more developed than the anal ; and the latter has either one or two
spines. In common with the two following families, the perches are further
characterised by the general presence of a lateral line, continuous from the head to
the tail, the usual absence of scales from the median fins, the simple conical teeth,
and the absence of barbels round the mouth. . In form the body is more or less
elongate, compressed, and cylindrical, although rarely it may be slightly compressed.
As now restricted, the family includes a dozen genera inhabiting the fresh waters
of North America, Europe, and Western Asia ; but the members of the genera
Lucioperca and Percarina enter salt water. All are carnivorous.

The common perch (Perca fluviatilis), which is a fish of wide
True Perches. ...... .,.,,,...

distribution, and one too familiar to require detailed description, is

the type of a small genus, agreeing with eight others in the following characteristics.

1 They are said to be thoracic when in the same vertical line as the pectoral fins, and jugular when in advance
of them.



336 SPINE-FINNED GROUP.

In the head the mucus or slime-canals, are but moderately or slightly developed on
the top and at the sides ; and the spinous and soft portions of the dorsal tin are
separate. In common with six other genera, the body is more or less compress .1 ;
the perches and pike-perches being specially distinguished by having usually seven
(rarely eight) gill-rays; by the premaxillse, or anterior upper jawbones, being
capable of protrusion ; and by the serration of the preopercular bone of the gill-
cover. As a genus, the true perches are distinguished from the pike-perches by
the small and uniform size of the marginal teeth, and the close approximation of
the pelvic fins. There are teeth on the palatine and vomerine bones, but none on
the tongue, and there are thirteen or fourteen spines in the first dorsal tin, and two
in the anal. The scales are small, the upper surface of the head is naked, the
preorbital as well as the preopercular bone is serrated, and there are seven branchio-
stegal rays, and more than twenty-four vertebrae. As in most of the members ul'
the family, the mouth is capable of a certain degree of protrusion. The common
perch, which seldom exceeds 5 Ibs. in weight, is distributed over the rivers of
Europe (except Spain) and Northern Asia as far east as Lake Baikal ; two others
being known, namely, P. flavescens from the Eastern United States and P. **}<,< ///,'/!
from Turkestan. Generally preferring still waters, and occasionally descending
into estuaries, the perch is one of the most voracious of fishes, feeding indiscrimin-
ately upon worms, insects, and small fishes. The spawning-season in England is
at the end of April or May, when the female deposits her eggs in net-shaped or
elongated bands on the leaves of aquatic plants. The eggs are very numerous,
upwards of two hundred and eighty thousand having been taken from a fish of
i Ib. in weight. Fossil remains of the genus occur in the Miocene rocks of CEningen,
in Baden, and those of the extinct Paraperca, in the upper Eocene of Provence.

The pike-perches, of which the common European representative
(Lucioperca sandra) is shown in the upper figure of the illustration
on p. 334, are inhabitants of many of the lakes and rivers of Europe, Western
Asia, and Eastern North America, and take their name from their somewhat
.elongated and pike-like form. From the true perches they differ by the presence
of more or less enlarged tusks in the marginal series of teeth, and by the wider
interval between the pelvic fins. The two dorsal fins are rather low, the lirst
having from twelve to fourteen spines; and the scales are small. The common
species, which is confined to Eastern Europe, where it is much esteemed as a food-
fish, grows to a length of 3 or 4 feet, and attains a weight of from :>5 to 30 Ibs.
Its extreme voracity and destructiveness to other fish render it an undesirable
inhabitant of preserved waters.

Danubian The two small and rather elongated perches represented in the

Perches. upper part of the illustration on p. 337, the larger of which is
known as As^o ziiiycl and the smaller as .1. m/i/nri*. maybe taken as repre-
sentatives of a subgroup distinguished from the foregoing forms and their allies
by the body being cylindrical or somewhat depressed; while from two allied
genera, they are distinguished by the maxilla or main upper jawbone, being covered
by the preorbital bone, and by the premaxilla being free only at the side. The
body is elongate and nearly cylindrical in form: and the mouth situated on the
lower surface of the thick and somewhat projecting muzzle. All the teeth of the



PERCH TRIBE.



337



jaws are of small and uniform size; and teeth are present on the vomer and
palatine bones. The anal fin has but a single spine; although the margin of the
propercular bone is serrated, that of the preorbital is smooth; and the scales are
small. These fishes inhabit the Danube and certain other European rivers.

Under this name, which belongs properly only to the British
form, may be included a few small perches, of which the typical
representative (Acerina cemua) is shown in the lower figure of the annexed illus-



Ruffes.




LARGER AND SMALLER DANUBIAN PERCHES, AND RUFFE (^ liat. size).



t ration. From the other members of the family this and the allied genus Percarina
differ by the large size of the slime cavities on the sides and top of the head; the
ruffes being specially distinguished by the dorsal fin being undivided, and also by
the maxilla being covered by the preorbital bone. The fishes of this genus have the
body somewhat low, and the scales somewhat small; the continuous single dorsal
fin carrying from thirteen to twenty-nine spines; and there being two spines in
the anal fin. There are no tusks among the small teeth of the jaws, and the
tongue and palatine bones are devoid of teeth, although these are present on the
vomer. The genus is confined to the cooler portions of the Northern Hemisphere,
VOL. v. 22



338 SPINE-FINNED GROUP.

the common .species ranging from Britain through Central Europe to Siberia.
The "pope," as the ruffe is frequently called in England, is common in most of the
rivers and canals of that country, generally preferring slow, shaded .streams, -with
a gravelly bottom, and closely resembling the perch in its mode of life.

Family Here may be mentioned a small family, with ten genera of

Centrarchidse. perch-like fishes, distinguished from the Percid<v and the following
family by the mode of attachment of the ribs, which, with the exception of the
last, or last two or four, are inserted on the bodies of the vertebrae behind the
transverse process, instead of the process itself ; all the vertebrae in front of the
tail, save the first two or three, having such processes. Externally these fishes
differ from the perches in the presence of at least three spines in the anal fin.
The family is typified by the North American genus Centrachus, of which then-
is but a single species. All are carnivorous fresh- water fishes, sometimes entering
estuaries, and many are in the habit of building nests for the protection of their
young.

BASS AND SEA-PERCHES, Family SERRANID&

Although usually included in the Percidce, with which they agree in the
structure and relations of the vertebrae and ribs, the sea-perches and their allies
are regarded by Mr. Boulenger as representing a family by themselves, on account
of the circumstance that the second suborbital bone develops an internal plate for
the support of the eye. The number of spines in the anal fin is variable: and in
one genus (Centrogenys) the lower pharyngeal bones are united. The family is
a very extensive one, and may be divided into several subfamily groups,
south American Together with the sea-perches, the bass represent a subfamily
Perch and Bass. (Serraninai) presenting the following characteristics. The upper
jawbone, or maxilla, is exposed, its upper border not being entirely concealed by
the overlapping preorbital ; the scales are not shed; there is no scaly process at
the bases of the pelvic fins; the anal fin has three spines; the gill-membrane is
free behind; and the false gills are well developed. In distribution the subfamily
is cosmopolitan, and while most of the forms are marine, a few inhabit fresh
water. Among the latter may be mentioned the South American perch
(Percicktkys'), of Chili, Western Argentina, and Patagonia, which, in common with
five other genera, has a divided dorsal fin. From an ordinary perch these iish
may be distinguished by the scaly upper surface of the head, and the presence
of nine or ten spines in the first dorsal, and three in the anal fin. To this sectioi
of the subfamily also belong the bass (Mnrone), which are partly marine and partly
fresh-water fishes, easily distinguished from the true perch by having only nim
spines in the dorsal fin, while there are usually three in the anal. There are
teeth on the tongue ; and while the preopercular bone is serrated, with dentieula-
tions on its lower border, the front border of the preorbital bone is entire.
The scales are rather small, and extend all over the head. Of the three European
and Atlantic species, which are almost entirely marine, the best known is the
common bass (J/. hihni.r), represented in the upper figure of the illustration
on p. 339, and characterised by its extreme voracity and fierceness. Elsewhere,
the genus is represented by fresh-water species from the rivers of the United



fiASS AND SEA-PERCHES.



339



States and Canada. Fossil species occur in the middle Eocene of Italy. Generally
not exceeding a foot or 18 inches in length, the common species may grow to
3 feet; but its flesh is then much less delicate than that of ordinary specimens.
Hnss frequent the coast in shoals, spawning in summer generally near the mouths
of rivers, up which they not unfrequently ascend for considerable distances.




COMMON BASS, SEA-PERCH, AND STONE-BASS (J liat. size).

_ In the other genera of the subfamily the dorsal fin is undivided,

Sea-Perch. . J

although it may be deeply notched ; the number of its spines being

generally nine or eleven, although there may be either eight, ten, or twelve.
Under the common title of sea-perches may be included the members of several
allied genera, such as Centropristes and Anthias, although the name is often
restricted to those of the typical genus Serranus, one of which (S. scriba) is
re presented in the middle figure of the above illustration. In the sea-perches the
body is oblong or compressed, and covered with small ctenoid or cycloid scales ;
there are large tusks among the villiform teeth of the jaws; and teeth are also



340 SPINE-FINNED GROUP.

present on the palatines and vomers, although absent from the tongue. The
preopercular bone is set-rated behind and at the angle, but not inferiorly ; and
the tail-fin may be either rounded, squared, or enia rginate. The sea-perches of
the genus 8erra/n>y& t of \vhich there are an enormous number of species, ran^e
through the seas of all the tropical and temperate regions, occasionally ascending-
tidal rivers for .short distances in pursuit of prey, but being otherwise strictly
marine. Many of the species vary considerably, both in colour and in the form
of their tins, with age, so that specific distinctions are difficult to establish.
Extinct species of this genus, .as well as others belonging to A^/rx, occur in
the middle Eocene deposits of Italy.

The fish represented in the lower figure of the illustration on
Stone -Bass.

p. 339, and commonly known as the stone-bass (Polyprion cernuum),

is one of two species constituting a genus distinguished from the last by the
absence of large tusks in the jaws, and the presence of teeth on the tongue :
the single dorsal fin having eleven or twelve spines, and the anal three. The
preopercular bone is denticulated, and there is a strongly marked rough longi-
tudinal ridge on the opercular. The common species is abundant on the
European coasts, while the second is from the seas of Juan Fernandez. Both
attain a very large size, ranging in weight to 80 Ibs. or more, their flesh being
of excellent quality. The European stone -bass frequents the neighbourhood of
floating wood, probably for the purpose of feeding on the creatures to be met with
around such objects.

oriental and The two species of the genus Lates, one of which (L. nttotirux)

African Perches. i n h a bits the mouth of the Nile, while the second (L. ealcarifer}
ranges from the shores of Baluchistan through the Indo-Malayan seas to China
and Australia, may be taken as representatives of another subfamily (Cen1r<>-
pomince), with three genera ; this subfamily differing from the last by the
extension of the lateral line on to the tail-fin, the presence of a scaly process at
the bases of the pelvic, fins, and the small size or absence of the false gills.
Having no teeth on the tongue, and a divided dorsal fin, these fish may be
distinguished externally from the true perches by the presence of seven or eight
dorsal, and three anal spines. Both the preopercular and preorbital bones are
serrated, and the latter denticulated at the angle; the finely pectinated scales
being of moderate size. The Indian perch, which may grow to a length of 5 feet.
is the only Oriental member of the family which commonly ascends rivers to any
distance. When taken in the larger rivers its flesh is excellent for the table,
great quantities being sold in the Calcutta market, where it is commonly known
by the name of cock-up. The allied genus Psammoperca is represented by two
species, one ranging from Australia to China, while the other is exclusively
Australian. There are many other generic representatives of this extensive
family, which are far too numerous to mention, no less than twenty-seven
occurring within the limits of British India. Among these the Indian genus
Pristipoma, which is referred by some writers to a separate family, is represented
by extinct species in the middle Eocene of Italy; and it may be mentioned here
that the earliest known forms of the family are the extinct genera YWor//x and
Acamu* from the lower Eocene of Switzerland.



SCALY-FINNED TRIBE.



343



THE SCALY-FINNED FISHES, Family CH^TODONTIJLE.



Nearly allied to the perches, the beautiful tropical fishes, designated scaly-
iiuned fishes, are so named 011 account of the characteristic feature of the median fins
being more or less thickly covered with small scales. In addition to this distinctive
feature, these fishes are characterised by the deep and compressed form of the body,
on which the scales are either ctenoid or entire, and the continuous lateral line,
which stops short of the tail-fin. The mouth, which is generally small, is placed
at the extremity of the muzzle, and has a distinct lateral cleft, and the eyes are on
the sides of the head. The small teeth are arranged in bauds, and there are neither
t u.sk s nor incisors. The soft portion of the single dorsal fin is rather longer than
>ln- spinous; the anal has three or four spines; the lower rays of the pectorals
are branched; the pelvic pair are thoracic in position, with one spine and five
soft rays ; and the scaling of the median fins causes them to pass imperceptibly
into the body. The great majority of these curious and beautiful fishes are
habitants of tropical seas, and are very generally found in the neighbourhood
coral-reefs ; but some ascend estuaries and tidal rivers, although but a
Hnparatively short distance. All are carnivorous, and of relatively small size,
iile they are but seldom used for food. The three genera of which examples are
presented in our illustration are those in which the zebra-like coloration attains
most marked and striking development; and for the beauty and singularity
their adornment these fishes are, almost unequalled Out of a large number of
fisting genera it is to these that our attention will be chiefly directed; and it
ly be remarked that the whole of them are met with in the Indian seas.
ctinct species of zebra - fish belonging to existing genera are found in the
liddle Eocene of Italy, among these being the Indian and Australian genus
jxotes. An extinct genus has been recorded from the Cretaceous of Westphalia.

The typical genus Ch't<xl<>n belongs to a group of genera in
which there are no teeth on the vomers or palatine bone, while the
)ines of the dorsal fin are not separated from the soft rays by a hollow or notch,
id. there is no spine to the preopercular bone ; the genus in question being
irticularly distinguished by the short or moderately long muzzle, and the
)proximately uniform length of the spines of the dorsal fin. These fishes are
ion in the tropical regions of the Atlantic and Indo-Pacific oceans, where they
re represented by some severity species. Nearly all are ornamented with bands
spots ; a dark, or two-coloured band, passing through the eye and then inclining
backwards, being very characteristic. Of the species represented, C. sefifrr,
ranging from the Red Sea to Polynesia, is readily recognised by the elongation of
the fifth ray of the dorsal fin, behind the base of which is a large dark spot
with a light rim ; (( I rifxci<it UK, which also has a similar range, but reaches the
coasts of India, is marked by numerous fine, longitudinal stripes on the body, and
se\eml dark bands across the head. On the other hand, in C. fasciat'US, ot the
Indian and Malayan seas, the body-stripes are oblique, and there is a single dark
hand across the head.

Especial interest attaches to this genus, which contains but few
species, and differs from the last by the elongation of the muzzle into






344 SPINE-PINNED GROUP.

a tube-like form, on account of the habits of one of its two Indian species (Cheliuou
rostratus). Of this fish, which has four dark bands on the head and body, and
an eye-spot on the soft dorsal fin, J. A. Schlosser wrote many years ago that it
frequented the shores and sides of the sea and rivers in search of food, and that
when it detected an insect perched on a plant it swam to within a distance of from
four to six feet, and then with surprising dexterity ejected out of its tubular mouth
a single drop of water, which never failed to strike the object aimed at into the
water, where it was immediately seized by the fish. Some of these fish kept in
tubs of water were seen to exercise their shooting powers even under these some-
what unfavourable circumstances. Somewhat later a Mr. Mitchell observed tlie
same action in some of these fish kept in a pond near Batavia about the year LS2S.
Curiously enough, in spite of these circumstantial statements, this capacity for
ejecting water was transferred to a short-snouted member of the present family,
which received its name of Toxotes from this presumed power. Bleeker states,
however, that when in Batavia he never witnessed this act, which is one the
mouths of these fishes would appear quite incapable of performing.

f The fish (Heniochus niacrolepidotus) numbered 4 in the illus-

Heniochus. . T , _ . , ,.

tration on p. 342, is a common Indo- Pacific member or a genus

differing from Chaitodon by the more or less marked elongation of the fourth spine
of the dorsal fin, which in the figured species assumes the form of a whip-lash.
Broad dark bands across the body are very characteristic of the genus ; and in
the young the head is armed with numerous horn -like processes, which arc
permanently retained in a species named H. varius.

The two large fishes shown in the illustration, swimming towards
the loft, belong to a genus distinguished from all the foregoing by the
presence of a large spine on the hinder-edge of the preopercular bone; the dorsal
fin having from twelve to fifteen spines. The genus includes some forty species,
with the same range as the typical representative of the family. The splendidly-
coloured emperor-fish (H. imperator), shown on the right side of the illustration,
ranges from the east coast of Africa to the Indian and Malayan seas, and has the
ground-colour of the body a deep blue, upon which are some thirty longitudinal
golden-yellow stripes. The eye-stripe and a patch above the pectoral fin are black
edged with yellow ; and the tail-fin is uniformly yellow. This species, which
attains a length of 15 inches, is extensively used in India for food. Beautiful as it
is, it is exceeded by the Indo-Malayan zebra-fish (H. diacanthus). In this species
the general colour is yellowish, with from eight to twelve vertical brown-edged
blue bands; the caudal fin is yellow, and the anal marked with bluish lines running
parallel to its margin. The genus Scatophagus may be given as an example of a
group in which the spinous portion of the dorsal fin is devoid of scales and separ-
ated by a deep notch from the soft part, PO that there are practically two dorsals.
The above-mentioned Toxotes, on the other hand, constitutes a group by itself.
in which there are teeth on the palatines and vomers, and the body is oblong
and much less deep than in the typical forms, with the undivided and ti\e-
spined dorsal fin situated in its hinder-half. It is represented by three species,
ranging from the Red Sea to the seas and estuaries of India, Malayana, and
Polynesia.



RED MULLETS.



THE RED MULLETS, Family



345



Two long erectile barbels dependent from the lower jaw serve at once to
distinguish the red mullets from all the preceding families, with which they
agree in the characters already mentioned. In these well-known fishes the body
is rather low and somewhat compressed, with large thin scales, of which the edges
may be very finely serrated. The lateral line is continuous, and the moderate-
sized eyes are situated on the sides of the head. The terminal mouth has a
rather short lateral cleft, and the teeth are very feeble. There are two short
dorsal fins, placed at a considerable distance from one another ; the spines of the
first being weak, and the second being placed above the anal, which it resembles in



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 36 of 62)