But whales have no gills, and they breathe air as you do. They are so
made that they can, with safety, remain under water for a much longer
time than you can. If a whale is kept under water too long, he drowns.
So we must leave whales, nar-whales, and porpoises out of our account
of fishes.
Among real fish you will find some of great size. Sturgeon have been
caught which weighed five hundred pounds. They were twelve or fourteen
feet long. Yet this size seems small when we compare it with that of
the great shark which has been found thirty feet long.
A queer contrast with such a vast creature is the little minnow, which
you catch in ponds and brooks. It is not much over an inch long. Little
English boys in their first fishing trips go for sticklebacks, a fish
from one to two inches long. I shall tell you in another lesson of this
amusing little fish.
The fish usually chosen as a type, or model, of the fish race, is a
perch. We find fishes[29] differing from the general perch pattern as
much as flower differs from flower.
The perch is a wedge-shaped fish, and is a beautiful creature. Let us
see how others of the fin family differ from the pattern I described
to you in the last lesson.
Instead of having a clear, round, full, bright eye like that of a
perch, some fishes, which live in mud, or in very deep water, have tiny
eyes, like dots. Some fishes which live in streams in dark caves have
really no eyes.
The perch is covered with scales of a rich green-brown and a golden
white. Some fish, as the eel and sword-fish, have no scales. A shark
has no true scales, but his skin has hardened into little bony points.
Some other fish, instead of scales, have large bony plates. The heads
and the fins seldom have any scales upon them.
If you could see a large collection of fish, you would wonder at the
variety of shape. You would see the “perch pattern” changed in almost
every possible way. Perhaps the first odd-shaped family to notice would
be the rays.
The fish of this family are flat. Their bodies are shaped much like a
flat triangle, finished with a long slim tail. The ray’s mouth is on
the under side of his body. The most common members of the ray family
are the skates. They are of a dark color above, and light below. I
shall soon tell you a queer thing about skates’ eggs.
One of the rays is called the sting ray, because its tail extends in
a huge lash, like an immense whip. Another ray is called the eagle,
because his body and fins widen out on each side, like the wings of a
big bird.
Another odd-shaped fin family is that of the flat fish. These, like
the rays, are dark above and light below. These fish are very flat or
thin in the body, and usually have both eyes and mouth on the upper or
dark side. There is one kind where the eyes and mouth are so raised as
to look much like the head of a bird. They swim with a queer wave-like
motion of the whole body. To this family belong the turbot, flounder,
plaice, and sole.
Then, too, there is a family of fish that are nearly as round as balls.
They have wide stripes of light and dark color, and look more like nice
play bells, furnished with tails and fins, than like fish.
A queer contrast to them is the pipe-fish. Pipe-fish have no scales.
Their bodies are long and slender, like very slim canes. They get their
name from the queer shape of their noses. The pipe-fish’s nose is very
slim and hard, and half as long as the fish. People think it looks like
a pipe, or cigar.
Many fish have very odd noses. Instead of the wedge-shaped head, with
the nose and mouth set exactly on the front, the nose may be of a
queer shape, and the mouth above or below.
The bellows-fish gets its name from a nose shaped almost exactly like
a bellows. One kind of sturgeon is called the shovel-fish, because its
head is shaped much like a wide shovel. Another sturgeon is called the
spoon-bill, because its nose runs out in a long, horny plate, like a
spoon, or a paddle. The hammer-headed shark, has its head broadened on
each side like a great hammer, with the neck for a handle. One eye is
set at the end of each projection.
I cannot tell you of all the queer shapes that fish take. If you
examine those which you catch in the ponds and rivers, or see brought
to market, you will observe that no two kinds are alike. What a narrow,
graceful, active fish a trout is! What a queer little fellow is the
fish that from his shape you call “a pumpkin seed.”
I told you just now, that one ray fish has a very long tail. With it
he strikes, and stuns or kills, his prey, or his enemy. Most fish live
on animal food. Some fish eat sea-weeds, but most of them prefer other
fish, crabs, insects, shell-fish, or other live creatures. Very many
fish have some weapon for securing prey, or fighting their enemies.
Some fish, depend on their quickness of motion to secure their food
or escape enemies. But I will now tell you of some of their weapons.
The lower lip of a salmon turns up into a sharp, cutting hook. The
sword-fish has a long, hard, sharp, strong horn, which it can drive
into the side of a ship. With this weapon it will also kill a man. The
sword is formed by some bones of the side of the head, growing out very
long and strong. The sword-fish belongs to the ray order.
Another ray is the saw-fish. This fish carries on its head a long, flat
bone set with great points like the teeth of a coarse saw. With this
weapon the saw-fish charges into a shoal of fishes. He maims and wounds
a number so that they die or cannot swim away. Then he feasts on them
at his leisure.
A very queer fish is the torpedo.[30] He is a very big fellow. He can
give a shock like electricity, that stuns or kills his prey. There is a
large eel which has the same power. They are both much feared by other
fishes.
But no fish is more feared by other fish, or by men, than the shark. No
doubt you have heard of him, with his huge mouth set with great hooked
teeth. He can kill almost any creature which is in the sea.
While much more could be said about weapons, we must now leave them to
take a look at the first pair of fins, or the breast fins.
In the rays the breast fins are broad and long. They are the chief
means of swimming. The flat fish have these breast fins extended all
along the side of the body. By the wave-like motion of these fins and
of the body they swim.
In some fish these breast fins are turned to feet, for walking at the
bottom of the water. There are one or two kinds of fish that can climb
trees. These have the under fins turned to sucker-like plates to help
them climb.
Did you ever hear of the flying fish? That fish has the breast fins
long and wide like wings. The fish can rise from five to twenty feet
above the water, and these fin wings support it, so that it can fly
about two hundred yards. Thus it escapes from its enemies.
You will see some fish with fleshy, finger-like organs near the mouth.
These are called barbels. Fish with barbels are bottom feeders. With
these barbels they hunt for food in the mud.
FOOTNOTES:
[29] Both _fish_ and _fishes_ are correct plural forms, and both are
used to accustom the child to both words.
[30] Also of the ray order.
LESSON XLII.
WHERE THEY LIVE.
Where does the fin family live? “In the water,” you say. Yes. There is
perhaps no natural body of water in the world without its fish. There
are forty families of fresh-water fish. There are fish that live in
water that is partly salt and partly fresh, as where the sea-tides run
back into rivers. There are fish that live in the salt water of the
ocean.
[Illustration: IN FRESH WATER.]
The ocean fish are divided into three classes. First there are the
coast fish, that seldom go far from shore. They need a certain kind of
food and a certain warmth of water that they find near land. Then there
are surface, or upper-sea fish, that live far from land, but never very
deep in the water. And there are the fish of the very deep sea.
The surface, or upper-sea fish, are most of them very strong swimmers.
The deep-sea fish live far down where there is little air and almost
no light. It is only about twenty years since people began to study
deep-sea fish, and as yet little is known about them.
Many of the shore, or coast fish, that live in sea-water, enter the
rivers to lay their eggs. They arrive in the rivers in the spring, and
sometimes go up even hundreds of miles from the mouth to find safe
places for their young. Thus these fish are born in fresh water, and
grow up in salt water.
Among fish of this habit, we find the shad and the salmon. So you see
a fish may live part of its time in salt water, part of the time in
fresh, and part of the time in the brackish water at the river’s mouth.
Some fish, that are accustomed to spend all their lives in sea-water,
can be made to live in fresh water, if this is changed gradually.
When fish live in a tank, air must be driven into the water to supply
what the fish use out of it. If air is not driven in, the fish will
die. As the oxygen in the water becomes scarce, the fish seem uneasy.
They come up to the top of the water, and put their mouths out for air.
They give a gasp as if choking.
In such tanks, where fish live, a jet of water is driven with some
force into the water of the tank from above. As it goes down, you see
a stream of shining bubbles. These bubbles are air. They break in the
water, and the air mingles with the water in the tank.
You may see gold-fish in globes coming to the top of the water, and
seeming uneasy and unhappy. Then if you dash in a little fresh water,
or take some of the water from the globe and pour it back from a little
height, the fish seem content.
You know that the driving winds and the tumbling waves that break in
foam will keep plenty of fresh air in ocean water, for all the finny
tribes that live there.
So rivers, as they rush and ripple, toss their waves, and are driven
with winds, get air bubbles mixed in their waters.
Some fish need more air than others, and often come to the surface to
breathe. Some, as the sturgeon, leap above the surface into the air.
Perhaps you have seen cat-fish jumping in this way. Did you ever see
dolphins and porpoises[31] roll themselves quite above the surface of
the water in their play? I have told you of the fish that make short
flights. In all these ways these creatures help themselves to air in
their water home. But what do they do for food?
As I told you, fish eat fish and insects and crabs and such living
things. Some few are feeders on vegetables. Fish will also devour
almost anything that is thrown into the water for them. Did you ever
feed fish in a pond with bread and worms?
Carp will hurry to the top of the water to get food that they have
learned to look for when people come near. Fish of a kind often keep
together and feed together. You know in a stream there may be some
places where you will catch only trout, or only bullheads. And in some
other place you will find pickerel.
In the sea you will find millions of herring together at certain
seasons. This is called a shoal of herring. Fish move from place
to place along many miles of sea-coast or river, as they seek their
especial food, or a certain warmth.
Sometimes a particular fish, or pair of fishes, will live for years in
some certain place. They may find a nice spot under a bank, where they
feel safe, and where plenty of food drifts near them.
I knew of a fish that went into a hole made by the roots of a great
willow-tree. The roots formed a close cage about him. He liked it well.
His enemies could not get at him. Water rippled in and out about him.
Grubs and worms were close to his mouth. He grew fat and big. He grew
so big he could not get out. He began to grow to fit the shape of his
cage. As he had no room to grow long, he grew broad.
After some years he was a very queer-looking fish. Finally, some men
were making an embankment, and they came upon this fish-home in the
roots of the tree. They took the fish out with care, and sent him to
a pond. I fancy it seemed odd to him to swim at first, after being so
long a prisoner.
There are some kinds of fish that live and thrive in the icy-cold
waters of polar seas. There are other fish that live in hot springs or
ponds, where the water is so hot that you can hardly bear your hand in
it.
Some fish can live only in very clean water. Others live in black and
muddy streams, and their flesh takes the dark hue of their home. In
fact, there seem to be some kinds of fish made to suit every kind of
water. This is very fortunate, as so many birds and beasts and so many
people eat fish.
FOOTNOTES:
[31] The dolphin of the Mediterranean is of the whale family, and
is not a true fish. The dolphin of the Atlantic is a true fish. The
porpoise is of the whale family, not a true fish, but a mammal.
LESSON XLIII.
HOW THEY BEHAVE.
[Illustration: ABOVE THE WAVE.]
Birds, beasts, and insects live where we can easily watch them.
Wherever we go, they are our near neighbors. We can easily find out
many facts about their way of living. For this reason, many people,
from the earliest times, have observed these creatures, and have
written down what they learned about them.
But of fish, people have been able to see and know much less. It has
taken much longer to learn about creatures that hide in the waters,
and are, for the most part, out of our sight. Seeing fish so much less
often, people took less interest in them.
Since great aquariums were built with glass tanks, in which fish can
live at ease and behave in a natural way, we have learned more of their
habits.
These tanks are filled with salt or fresh water, as the fish may
require. The floor of the tank is covered with sand, rock, shells. Then
crabs and small “shell-fish” of many kinds, and larvæ and worms are put
in, such as the fish would find in their native homes.
Caves and grottos, lined with moss and weeds, are built; and the tank
looks like a true part of a river, pond, or sea. Then the water is kept
at the right warmth, and fresh air is driven in as I have told you. The
light is made just right for the fish in the tank, and proper kinds of
fish are put together.
When you go and stand outside of one of these great tanks, this water
world is before you from top to bottom. Now I shall tell you some of
the things which I learned about how fish behave at home.
By such a tank I first learned that nothing can be more easy and full
of grace and majesty than the motion of a fish in the water.
I watched a great fish swimming. I could not see the motion of a
muscle, or the least quiver of fin or tail. His great round eyes shone;
his splendid red fins were still; his spotted back glistened through
the waves; his broad sides gleamed in silver mail.
He never seemed to stir from his majestic calm. He stole across the
line of vision, but without visible effort. He crossed the path of
other fish. He sailed above them or below them; but he seemed to feel
himself all alone, and to notice nothing.
A fisher who had watched pike told me that, when he watched one lying
in a pool, he was sure that the fish saw him. It did not seem to make
any motion. But the fish changed its place. Soon it was gone.
In the next tank to the one I spoke of, were flounders. They swam
with a wave-like motion of the whole body. They did not swim straight
forward. They went up and down in curves. Their motion was much like
the flight of short-winged, heavy birds. In fact, a sole which had its
eyes and mouth set upon a kind of skull-shaped head, on the upper side
of the flat body, looked much like a dim, first idea of a bird.
The fish in the tank were not fish that fed on each other, and they
never seemed to notice each other at all.
I saw some kinds of fish asleep. A dog-fish lay asleep on the sand,
with his nose in a corner, for half a day. He looked as if he were
dead. Three hermit crabs[32] were crawling about over him. He never
stirred. He did not seem to notice their sharp claws and their jostling
shells.
This sleeping of the dog-fish reminded me of what I had seen in pools
where fish lie basking in the sunshine. Some fish are very fond of
lying in a sunny spot. Others will get into a shadow, and lie there
with great content.
I found in my study of fish life in tanks, that fish are given to
fighting. Some of them fight with their nearest relatives. In a small
tank I saw two fish that fought and bit each other so cruelly that they
had to be parted.
There had been several fish in this tank, and all but two had been
killed in their battles. Then a glass partition had been put in the
middle of the tank, and one fish lived on each side. They swam up to
this clear wall, laid their noses against it, and glared at each other.
Another fact I remarked in fish is the clearness and keenness of their
vision, and the quick way in which they will dart at food. When they
see something that they wish to eat dropping down through the water,
they spring at it with open mouths, and seem never to miss their mark.
When they need more air than they can get from the water, they swim to
the surface and take a gulp of air and water. When they are sick, they
do not swim, but lie on their sides, as if they feel too weak to make
any effort. When they are dead, the bodies turn over and float on their
backs.
It is said that fish can reproduce parts that they have lost, as crabs
and star-fish can. At least, they can easily live when an eye or part
of their mouth or a fin is gone. They seem to suffer little from such a
loss. A fish that has a wound, or has just lost an eye, will swim about
and eat as if it felt no pain.
Some fishes that live on the bottom have a queer way of lying close on
the sand, with their mouths wide open. They pant as if in great pain.
But they are not in pain, they are sifting their food out of the water.
Look into their throats, and you will see a network, like fine bones.
That is their sieve to catch small food.
Some fish are timid, and hide at the least sound. Others are fearless,
and lie in plain view, or boldly follow their prey. A fish darting
after his food is a fine sight. His jaws are open; his spines stand in
a ridge on his back; his eyes gleam. His whole body seems alert and
full of fire.
You should watch fish for yourselves. You have seen gold and silver
fish in globes. Other fish are often kept in ponds and fountains as
pets. They become very tame. Sometimes they learn to know those who
feed them, and will come when called.
FOOTNOTES:
[32] See Nature Reader, No. 1, Lesson 8.
LESSON XLIV.
FRY AND SCHOOL.
A fish comes from an egg, as a bird does. There are one or two kinds
that are born as little live fishes. But the rule is that the fishes
hatch out of tiny eggs. The mother fish drops these eggs in the water,
or carefully lays them in some place which she prepares for them.
[Illustration: A CURIOUS CRADLE.]
After they are laid, these eggs are called spawn. Before they are laid,
they lie in a solid mass together. There are many thousands of them
in each mass, and they are then called roe. I have told you of the
wonderful number of eggs laid by insects. But fish surpass even the
insects in the number of eggs.
These eggs are subject to very many dangers. Fish, crabs, and
water-fowls eat them. The waves may dash them ashore, and so they will
be dried up. Therefore it is needful that there should be a great many,
so that after all disasters a large number may hatch.
The eggs of fish are of a pearly white, or a cream color. They are
covered with a kind of glue, so that they stick together. They also
stick to weeds, or rock, or sand, where they are laid.
There are very few fish that carry their eggs about with them, after
they are laid. The fish presses its body against the eggs, which stick
to it, and are carried about, until they hatch. You have read of the
crab which took care of its eggs in this way.[33]
As the little fish grows within the egg, the soft skin-like case
becomes very thin. When the time comes for hatching, the little fish
breaks the case, and comes out. As a general rule, the little fish,
just out of the egg, looks and acts like the parent fish. But there are
some that change much between their first and their full-grown states.
Let us now look at some curious fish eggs and fish nests. Of all the
fin family, the dog-fish has the most curious cradle for its young. The
egg-case of the dog-fish is a horny bag, or purse. It is of a gray or
blackish color, about an inch wide, and two inches long. At each of the
four corners, it has a long, stiff, curly stem.
The mother dog-fish swims near the shore to lay her eggs. She selects
a weed, branch, or piece of tree, lying in the water. To this she ties
her egg-cases by means of their long stems, or strings. She does this
by swimming round and round the twig to which she means to fasten the
case. As she drops the case in the water, she ties it, or binds it, by
drawing with her the curly ends, as she swims, about the branch.
She lays a number of these purses in a place. Then she swims off and
leaves them. It is lucky that she does, for if she stayed near them,
she would eat the little fish as soon as they came out!
I have seen a dog-fish tying its eggs to a branch lying under water,
and it was a queer sight. When the baby fish has grown large enough to
leave the case, it makes a little opening on one end, and creeps out.
The skate, that is a cousin of the dog-fish, lays a case much like
this. But the case of the skate is of a shape more nearly square. It
has four sharp, curved horns, not long, curly ends; and the little
skate comes out of a hole in the middle, never at the end.
Another sea-fish, the mackerel, has no such protection for its eggs.
It drops thousands of them on the water, and they look like tiny
pearl beads. They sink to the bottom. As they are sticky, they cling
together, and to the sand, until they hatch.
That prettiest of fish, the trout, which lives in so many clear, shady
streams, where there are deep, quiet pools to bask in, is very careful
of her eggs. The mother trout sinks to the bottom of some clean stream,
and selects a nice sandy place. Then, with her tail, she fans out all
the coarse sand and gravel. If there are larger bits of pebble, she
carries them off in her mouth.
When she has made a nice smooth little nest, like a cup, she drops her
eggs into it. Then she covers them lightly with gravel, so that they
will not be floated away. When she has finished one nest, she swims off
to make another.
The black bass of our lakes and ponds makes a smooth bed for its eggs.
It prepares this bed in the shadow of a stone or sunken log. Several
bass will go together, and select and clear out such a bed. Then they
will lay their eggs there, and for days, until the eggs hatch, will
swim about near, to keep watch over them. Eels, cat-fish, perch, and
suckers, come to eat these eggs, and the big bass drive them away.
The pretty perch does not take such care as this of her eggs. She drops
them in long chains, among grasses, and leaves of water-plants, at the
edge of the pond. When the yellow cowslips are in bloom, you can find
these eggs among the water-plants, like strings of fairy beads.
When the baby perch come from the eggs, they are very nimble, and begin
at once to eat. When they are no longer than the nail of your little
finger, it is funny to see them in the water, darting after the living
atoms that serve them for food.
They see and know these tiny things in the water, and pounce upon them
with wide-open mouths.
The little fish, from the time they are out of the egg, until they
are about half grown, are called fry. Some fish, as the salmon, get
different names at different periods of their growth. A great many fish
together are called a school. Thousands of fish will come leaping,
rolling, and tumbling along in the water, and we say it is a school of
fish.
FOOTNOTES:
[33] Nature Reader, No. 1, Lesson 3.
LESSON XLV.
SCALES AND TEETH.
I told you that most fish had scales, and that these scales clothed
them in a gleaming, flexible suit of armor. Most of the beautiful color
of fish is found upon their scales. Many of the scales are iris or
rainbow hued. That is, they have the gleam of many colors, according as
the light strikes them. Have you not seen such colored light in a glass
prism?
The scales of different fish vary in shape, size, color, and hardness.
In general, they are horny like your finger nail, but thinner. Their
shape is nearly round, much like a rose petal. They are fastened by the
smaller edge to the skin of the fish. Then each scale laps over the
next one, and so on.