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seen from the two following accounts, there is some difference of opinion an
observers. The first of these two accounts is abridged by Dr. Giinther from < (in-
published by Dr. Mobias, and runs as follows: "Flying-fish are more frequently
observed in rough weather and in a disturbed sea than during calms ; they dart
out of the water when pursued by their enemies, or frightened by an approaeliin-
vessel, but frequently also without any apparent cause, as is also observed in many
other fishes; and they rise without any regard to the direction of the wind or
waves. The fins are kept quietly distended, without any motion, except an
occasional vibration caused by the air whenever the surface of the wing is para
with the course of the wind. Their flight is rapid, but gradually decreasing
velocity, greatly exceeding that of a ship going ten miles an hour, and extend
to a distance of five hundred feet. Generally, it is longer when the fish fly agai
than with, or at angle to the wind. Any vertical or horizontal deviation fn>
straight line is not caused at the will of the fish, but by currents of the air;
fish retaining a horizontally straight course when flying with or against the wi
but being carried to one side whenever the direction of the latter is at an angle
that of their flight. It may, however, happen that in the course of its flight a
may dip its tail in the crest of a wave, thus changing its direction to the left
right. In calm weather the line of flight is always also vertically straight,
rather parabolic, like the course of a projectile, but in a rough sea, when tin-
are flying against the course of the waves, it may become undulating. Ins
instances the flying-fish Frequently overtop each wave, being carried over by th
pressure of the disturbed air. Flying-fish often fall on board vessels, but thi
never happens during a calm, or from the lee-side, always taking place in a In



STICKLEBACKS. 403

and from the weather-side. In the daytime they avoid a ship, flying away from
it ; but, during the night, when they are unable to see, they frequently fly against
the weather-board, where they are caught by the current of air, and may be thus
carried to a height of some twenty feet above the surface of the water." In the
second account, which was published many years ago in Land and Water, the
author writes that in calm weather flying-fish " are capable of clearing three
hundred yards. Their flight is frequently extended to double the distance by
simply skimming the surface, as a swallow does a pool, and without disappearing.
I have observed that they never touch the surface more than twice consecutively,
though they may resume their flight after a period of complete immersion ; while
still in the air, they readily change their course to right angles with their first
line of flight, or even completely reverse it towards the point from which they
originally started. I have watched them for hours through a powerful double
glass, as they rose from either side of the bows of the ship, and noticed that the
pectoral fins are moved with a slight but very rapid quivering motion, which, I
have no doubt, assists to sustain them in the air. In rough weather the flight of
the flying-fish is more rapid, much higher, and of shorter duration than when light
winds prevail." This account confirms my own observations as to there being a
vibratory motion of the pectoral fins when first leaving the water, although the
writer is probably incorrect in his supposition that this assists the flight.

STICKLEBACKS, FLUTE-MOUTHS, AND TRUMPET-FISH, Families GASTEOSTEID^:,
AULOSTOMATID^;, and CENTEISCID^E.

Although the third of the above-named families is regarded by Dr. Giinther
forming a group apart, we may follow Day in placing the whole three in a
ingle section, characterised by the spinous dorsal fin, when present, being either
short or formed of isolated spines, and by the generally abdominal position of the
pelvic fins, which in some instances are imperfectly developed.

Familiar to every home-born. Englishman as the fish upon which,
Sticklebacks. . J

in common with minnows, he made his first experiment in angling

with the aid of a bit of twine, a bent pin, and a worm, the sticklebacks have the
honour not only of representing a genus (Gastrosteus), but likewise a family by

I themselves. Taking their name from the presence of a variable number of isolated

II spines in advance of the soft dorsal fin, sticklebacks have the body more or less
j| elongate and compressed, the cleft of the mouth oblique, and the teeth villiform.
BtThe gill-cover is unarmed, and the cheek covered by the iiifraorbital bone ; and
iftn place of scales there are generally large plates along the sides of the body. The
1 pelvic fins, although abdominal in position, are connected with the pectoral girdle
i.by means of the pelvic bones, and consist of but one spine and a single ray; and
I there are but three branchiostegal rays. Confined to the Temperate and Arctic
Bpones of the Northern Hemisphere, where they are represented by some half-score

>pecies of small bodily size, sticklebacks are mainly fresh-water fishes, although the

pea-stickleback (G. spinachid) is a marine or brackish- water form, and all the

i ! rest can live as well in salt as in fresh- water. The British fresh- water repre-

^entatives of the genus are distinguished by the number of the dorsal spines, and






404



SPINY-FINNED GROUP



are known as the three-spined (G. aculeatus), four-spined (G. spinulosus), and nine-
spined sticklebacks (G. pungitius) ; while in the United States G, novG&boraccnxis
is the most familiar kind. The three-spined stickleback is a singularly variable
species, the plates which are present on the sides of the body in some specimens,
being wanting in others ; the unprotected condition being especially common in
the race from Central Europe. Very different in appearance from the others is
the fifteen-spined, or sea stickleback, in which the body is very long and thin ;
this species ranging as far north as Norway and the Baltic. It has recently been
ascertained that all the individuals of this stickleback die within a year of their




GROUP OF STICKLEBACKS.



Sea-stickleback (upper figure) ; Nine-spined stickleback (middle figure) ; and Three -spiiied stickleback

(lower figure), (nat. size).

birth; so that we have here a second example of an annual vertebrate, the first
being the one mentioned on p. 389.

Sticklebacks are extremely pugnacious, and at the same time highly voracious
fishes, the males engaging in fierce conflicts with one another; while both sexes
consume a vast quantity, of the fry of other fish, and an-, then-fore, most objec-
tionable denizens of preserved waters. It is not, indeed, that a single stickleback
can do a very great deal of harm, but the mischief results from the enormous
numbers of these little marauders. As an instance of this, we may once more
( | note the well-known statement of iVnnant, that a man employed by a Lincoln-
shin-, farmer to rid a stream of sticklebacks, for a considerable time made four
shillings a day by selling his catch at the rate of a halfpenny per bushel. In




STICKLEBACKS AND FLUTE-MOUTHS. 405

hting, the males make full use of the formidable spines on the back, with which
ey have been seen to rip open the body of an antagonist. The most interesting
it in the economy of sticklebacks is, however, undoubtedly the nest-building
bit of many of the species. In the sea-stickleback the nest is composed of a
mass of pendent seaweeds, bound together by a silk-like thread into a pear-shaped
form, in the centre of which are deposited the eggs. Such a nest lias been known
to be guarded for a period of upwards of three weeks by the male parent fish ; and
win -n it sustained any damage, by which the eggs were exposed to view, the
watchful guardian set about repairing the mischief with the greatest despatch and
energy, thrusting its nose deep into the structure, and pushing and pulling the
materials till all was once more sound. The following account of the nesting of

o o

the fchree-spined stickleback in an aquarium was forwarded by a correspondent to
Frank Buckland. On this occasion the male " selected a spot nearly in the centre
of the trough, and busily set to work to make a collection of delicate fibrous
materials, placed on the ground, and matted into an irregularly circular mass,
somewhat depressed, and upwards of an inch in diameter, the top being covered
with similar materials, and having in the centre a rather large hole. His work
was commenced at noonday, and was completed, and the eggs deposited by half-
past six in the afternoon. Nothing could exceed the attention from this time
evinced by the male fish. He kept constant watch over the nest, every now and
then shaking up the materials and dragging out the eggs, and then pushing them
into their receptacle again, and tucking them up with his snout, arranging the
whole to his mind, and again and again adjusting it till he was satisfied ; after
which he hung or hovered over the surface of the nest, his head close to the
if ice, the body inclined upwards at an angle of about 45, fanning it with the
ctoral fins, aided by a side-motion of the tail. This curious manoeuvre was
parently for the purpose of ventilating the spawn; at least by this means a
rrent of water was made to set in towards the nest, as was evident by the
itation of particles of matter attached to it. This fanning or ventilation was
queiitly repeated every day till the young were hatched; and sometimes the
ih would dive head foremost into his nursery and bring out a mouthful of sand,
ich he would carry for some distance and discharge with a puff. At the end
a month the young ones were first perceived. The nest was built on the 23rd
of April, the young appeared first on May 21. Unremitting as had been the
attention of this exemplary parent up to the time of the hatching of the eggs, he
now redoubled his assiduity. He never left the spot either by day or night; and
<luring the daytime he guarded it most pertinaciously, allowing nothing to
approach. . . . The fry were at first so minute and transparent that they were
scarcely perceptible, and it was only by a slight fluttering motion their position
could be occasionally discovered ; otherwise it was impossible to detect them."

Although the name of pipe-fishes is frequently applied to the
Flute-Mouths. rr .

members of the second family of the group under consideration, it

is better to restrict that term to the Syngnatliidce (described in the sequel), and
take that of flute-mouths for those to be now noticed. As a family, the flute-
mouths are readily distinguished from the sticklebacks by the production of the
bones of the muzzle into a long tube, terminated by a small mouth ; and likewise



406 SPINY-FINNED GROUP.






by the pelvic fins consisting of six soft rays. The greatly elongated body is either
covered with ver}~ small scales, or naked; the teeth are small; the first dorsal, if
present, is formed of small isolated spines ; the soft dorsal and anal are of moderate
length; the pelvic fins consist of six rays, without any spine, and are separated
from the pubic bones, which remain attached to the pectoral arch ; and there are
five branchiostegal rays. The air-bladder is large, and the vertebrae are very
numerous, those in the anterior part of the column being fused into a continuous
tube, as in the flying gurnards. These fishes, which may be regarded as gigantic
and highly specialised marine sticklebacks, frequent the coasts of the tropical and
subtropical portions' of the Atlantic, Indian, and Pacific Oceans, some of them
growing to from 4 to 6 feet in length. In the genus Fistula ri<(, the body is
naked, the forked caudal fin has one or two of its middle rays produced into a
long, whip-like filament, and there are no isolated spines to the dorsal fin. The
species are confined to the Tropical Atlantic and Indian Oceans. On the other
hand, in the typical genus Aulostoma the body is covered with small scales, the
caudal fin squared, and without filaments, while the back carries a series of small
isolated spines, and the teeth are rudimentary. In this genus the species inhabit
the Atlantic ; but the third genus (Auliscops) is represented by a single form from
the North American Pacific coast, distinguished by the naked body, the thoracic
position of the pelvic fins, and the presence of numerous spines in front of the
dorsal fin. Day states that he found the Indian species of Fistularia, which is
common at Madras, frequenting the most muddy localities.

Trumpet-Fishes, While agreeing with the flute-mouths in the production of the
etc - muzzle into a tubular beak, the two genera of fishes constituting the
family Centriscidie differ by the imperfect development of the pelvic fins, which
are truly abdominal in position. They have two dorsal fins, of which the spinmis
one is short, while the soft one is similar to the anal. Teeth are wanting. The
family is distributed over the Atlantic, Mediterranean, and Indo- Pacific, the
common trumpet or bellows fish (Centriscus scolopax) occasionally making its
appearance on the south coast of England, while it is also known from such a
distant region as Tasmania. It belongs to a genus characterised by the oblong or
elevated and compressed body being covered by small rough scales, with some
bony strips on the back and under surface, the absence of a lateral line, and the-
length of the spines of the first dorsal fin. The second genus, Amphisile, differs 1>\
the elongate form of the compressed body, which is covered on the back with a
cuirass of bony plates, behind which are the two dorsal fins. This genus is
confined to the Indo-Pacific; and in the Indian A. scutata the dorsal armour
terminates behind in a long spine, close beneath which are the three spines of the
first dorsal fin, followed by the second dorsal, the caudal appearing on the lower
sui'face of the body just behind the anal. Dr. Giinther writes that in these
tortoise-fishes, as they may be called, the " body is so thin that it has the appear-
ance of being artificially compressed between two sheets of paper: it is scmi-i
transparent, especially in the region of the air-bladder. The structure of the
vertebral column is extremely singular, and unique among Acanthopterygians,
The, trunk portion is more than four times as long as the caudal, nevertheless ifi
is composed of only six vertebrae, whilst the latter consists of fourteen." The



SUCKER-FISHES.



407



trunk vertebrae are extremely slender, the third alone being nearly as long as the
whole caudal portion ; while in the latter all the vertebree are very short. In a
,sil state the tortoise-fishes are represented in the middle Eocene of Monte Bolca ;
and it may be mentioned here that in the preceding family the genera Fistularia
and Aulostoma occur not only in those deposits, but likewise in the lower Eocene
of Switzerland ; and Auliscops has been recorded from the Eocene of Sumatra,
and two extinct generic types have been described from the Monte Bolca beds.



THE SUCKER-FISHES, Family

The small fish (Lepadoy aster bimaculatus), of which three examples are
)wn in the annexed illustration, is one of three British representatives of a genus
^longing to a small family which constitutes a sectional group by itself. Long



TWO-SPOTTED SUCKER-FISH mat. Size).




unfounded with the lump-suckers, which they resemble in having an adhesive
isc on the under surface of the body, the sucker-fish differ from that group, not
only in the structure of that disc, but likewise in several other respects. They have
no spinous dorsal fin ; the soft dorsal and anal are short or of medium length, and
situated far back, at the root of the tail ; the pelvic fins are almost jugal in
position, and have the adhesive disc placed between them ; while the body is
covered with a naked skin. Whereas in the lump-suckers the pelvic fins are close
together, and actually form the base of the sucking disc, in the present family
they are widely separated from each other, and only enter into the composition
of a portion of the margin of the adhesive apparatus, which is completed by a
cartilaginous expansion of the bones of the pectoral girdle. In size the ovoid disc
is relatively large, its length being sometimes as much as one-third that of the
whole fish, and it is divided into an anterior and a posterior moiety, of which the
second may or may not have a free front margin. All these fishes are littoral
forms of small size, ranging over both temperate zones, where they are more



408 SPINY-FINNED GROUP.

numerous tlian in the tropics. Among the numerous genera we can only mention
the typical (}<il>i<H>xt>.f, from the West Indies and Pacific coast of South America,
distinguished by the absence of a front free margin to the posterior division <>i'
the sucker, and the presence of incisor-like teeth at least in the lower jaw; and
the European Lepadogaster, in which the hinder-half of the sucker has an anterior
free margin, and the teeth are small and fine. The British species, although
variable in this respect, are very prettily coloured ; the figured one being generally
carmine-red above, and pale flesh-colour below,. with a light patch between the
eyes, and two more or less distinct spots on the sides. It has been obtained
adhering to stones and shells in deep water off Torquay. Montagu writes that
when placed in a vessel of sea- water these little fish ' : always adhered to the sides of
the glass by the apparatus termed the sucker, and frequently remain fixed till they
died ; and even after death the power of adhesion continues. The wet finger being
applied to the part, the fish becomes suspended ; when alive, they instantly attach
themselves to the hand if taken out of the water."

THE SERPENT-HEADS, Family OPHIOCEPHALID^.

Mainly characteristic of the Oriental region, although also represented in
Africa, the fresh-water fishes known as serpent-heads are interesting not onl\
on account of their structure, but likewise from their peculiar habits. They form
a single family, constituting a sectional group by itself, and represented by two
genera, in one of which (Ophiocephalus) pelvic fins are present, while in the
second (Cltanna) they are wanting. As a family, the serpent-heads are character-
ised as follows. The body is elongate and covered with medium-sized scales : all
the fins are devoid of spines, the anal and single dorsal being long and low; and
there is an additional cavity above the proper gill-chamber, although this is not
furnished with supplemental gills. The depressed head is covered with somewhat
plate-like scales, and has the eyes lateral and the gill-openings wide ; each gill-
chamber containing four gills, while teeth are present on the jaws, palatines, and
vomer. If present, the pelvic fins are thoracic in position, and composed of six
rays. The lateral line is sharply curved or almost interrupted, and an air-bladder
is present. Of the typical genus there are some thirty existing species, having
a distribution coextensive with that of the family, and in Asia ranging ov<
Baluchistan, Afghanistan, India, Ceylon, Burma, China, Siam, and the Mali
Archipelago; the figured species (0. striatus) being common to such distai
localities as India and the Philippines, and at times reaching as much as a yai
in length. The second genus, Channa, is represented only by a single species fr
Ceylon and China. In a fossil state these fishes have been identified from tl
Pliocene rocks of the Siwalik Hills in North-Eastern India.

In India the serpent-heads are found both in rivers, ponds, tanks, and swam]
many of them seeming to prefer stagnant to running waters. Day writes that
these fishes "having hollow cavities in their heads, and an amphibious mode of
respiration, are able to exist for lengthened periods out of their native element,
and can travel some distance over the ground, especially when it is moist. They
are able to progress in a serpentine manner, chiefly by means of their pectoral



SERPENT-HEADS.



409



and caudal fins, first one of the former being advanced and then the other. These
fishes appear to be monogamous, some breeding in grassy swamps or the edges of
tanks, some in wells or stone-margined receptacles for water, and others again in
holes in river-banks. The varieties which live in tanks and swamps keep much
to the shallow and grassy edges. Amongst the fish which I myself saw exhumed
from the mud of a dried-up tank were some Ophioccphali ; they are also recorded
by the natives of India as descending with downpours of rain." When living in
muddy water they rise to the surface from time to time to take in atmospheric
air, and captive examples prevented from doing this have been known to die.





STRIATED SERPENT-HEAD (?; liat. size).

During the time they are buried in hard mud it must be assumed that these fish
(become completely torpid and stop the respiratory function.

LABYRINTH-GILLED FISHES, Families ANABANTID^: and LUCIOCEPHALID^.

In the members of these two families of estuarine and fresh-water fishes,
which constitute a sectional group by themselves, the apparatus for enabling
them to exist for a considerable time out of the water is carried to a greater
degree of complexity than in the last, and takes the form of a laminated accessory
gill-like organ, situated in a chamber on each side of the head above the one
containing the true gills. In these fishes the body is compressed, oblong, and
elevated, with medium-sized ctenoid scales. The eyes are lateral, the gills four
in number, the gill-opening rather narrow ; and false gills either rudimentary or
wanting. The single dorsal fin, as well as the anal, has a variable number of
spines ; and the pelvic fins are thoracic in position. While in some cases the
lateral line is interrupted, in others it is altogether wanting; and the air-bladder
may be either present or absent, but when developed it is generally very large,
sometimes even extending into the tail. These fishes, which are of comparatively
small size, are confined to Southern Asia and South Africa, and are all capable of
existing for a longer or shorter period out of their native element, when they
oxygenate their blood directly from atmospheric air by means of the accessory



4 io SFINY-FINNED GROUP,

gill-like organ. Whereas some are carnivorous, others are vegetable-feeders ; but
all are capable of domestication, in which state they are subject to considerable
variation, and several have been acclimatised in countries other than their own.
The flesh of all of them is said to be eatable, and that of some is of excellent
quality. On account of their brilliant coloration, and the curious habits of some
of them, these fish have always attracted more than ordinary interest.

The fish to which the somewhat inappropriate name of climbing-
Climbing-Percli. ./ j r ,7 \ i, i i TTI,^

perch (Anabas scandens) has long been applied by Europeans in




CLIMBING-PERCH ON LAND (^ nat. size).

India is the sole representative of a genus characterised by the presence of teetl
on the palate, and the serration of the free margins of the opercular and preorbita
bones. In form the body is compressed and oblong ; the lateral line is interrupted I
the single dorsal fin has its spinous portion much longer than the soft part; whil'
in the anal fin the spines are less numerous than those on the back. The cauda^
fin is rounded, and the scales are rather large. In length the climbing-perch ma;
reach at least Si inches, and in the adult state its general colour is dark greei
usually marked with dusky bands, which disappear soon after death. It frequent!



PARADISE-FISH. 411

poth estuaries, rivers, and tanks, and is distributed over India, Ceylon, Burma,
:he Malay Archipelago, and the Philippine Islands. That this fish can travel
<mg distances on land, where it drags itself along by hitching its pectoral fins
oiind the stems of grass and other herbage, in the manner indicated in our
1 lustration, is perfectly well ascertained. With regard to its climbing powers
>me amount of incredulity has been expressed, but it is very noteworthy that
ts Malayan name (undi-colli) signifies tree-climber, while nearly a thousand years
igo certain Arab travellers were informed of the existence in India of a fish that
,\ as in the habit of ascending cocoa-nut palms to drink their milk. Apparent!}'
only definite record that we have of a European having witnessed such



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 43 of 62)