see, in our next lesson, what strange weapons are used in the battles of
the fish. The Rays or Skates have their share of spines, stings, and
poisons. One glance at their shape tells you that speed is not their
strong point. If they wish to eat fast-swimming fish--and they often
do--they must use cunning.
The Skate, being sandy-coloured and flat, is nearly invisible as it lies
on the bed of the sea. There it lurks, waiting for the first unwary
fish. A sudden spring, and its wide body smothers its unlucky victim.
Skates also flap their way slowly over the ocean floor, looking for a
dinner. They can eat shell-fish, and are fitted with teeth suited to the
work of crushing such hard fare. But, as we have seen, they have also
the Shark's love of eating other fish.
These Skates are the only members of the Shark family that we value as
food. You can see Skates of several kinds in the fish market. They go by
such names as Thorn-back Ray, Blue Skate, Spotted Ray, Starry Ray,
Cuckoo Ray, Long-nosed Skate and Sting Ray.
EXERCISES
1. Of what use are Sharks? 2. How does the Thresher Shark hunt its prey?
3. Give the names of several Dogfish and Rays. 4. What is the food of
the Skate, and how is it obtained?
LESSON VIII
THE DANGERS OF THE DEEP
The "game" of hide-and-seek is played by most of the dwellers in the
sea. Many of them are "hiders" and "seekers" by turn. That is to say,
they are always seeking other creatures to devour, but must also be
ready to hide from their own enemies.
_Eating and being eaten_--that is the life of the sea. The small and
weak ones must hide, and their lives depend on their skill in hiding.
Perhaps we should not call it a "game," as it is not done for fun. But,
though the sea is full of danger for some creatures, you must not think
that they live in fear. There is no doubt that they enjoy their lives,
each in its own way.
Many are the quaint dodges and tricks of the hiders and seekers in the
sea. We can mention but a few in this lesson. Look at the Spider Crabs,
and their trick of dressing up. They have hooks on their backs, which
catch in the seaweed. Some of them even tear off weed with their
pincers, and fix it on to these hooks, and succeed in looking like
bundles of weed, and not a bit like living Crabs.
Then there are the fish which wear a coloured scaly coat. Many of them
are not easily seen in the glinting water, as you know. Others are lazy;
they lie on the bed of the sea, and wear a disguise which hides them
from prowling foes. The Plaice and other flat-fish, as we noticed in
Lesson 2, are coloured and marked like the sand and pebbles of their
home; and they can even change colour to suit their background. They are
wonderfully hidden, owing to this useful dodge. It is as if Mother
Nature had given them the marvellous "cloak of invisibility," of which
we read in fairy-tales.
Shrimps and young Crabs wear a coat of sand-colour or weed-colour. Our
soldiers, for much the same reason, wear suits of _khaki_.
Another common hide-and-seek trick is to look like nothing at all. That
sounds difficult, but it is a favourite dodge in the sea. If a number of
very young Herrings or Eels were placed in a glass tank of sea-water,
you would have a hard task to find them. You can look _at_ them, and yet
not see them. They are transparent--you look through them as if they
were water or glass. You can imagine how well hidden they are in the
open sea.
It is well to be able to hide, when all around you are enemies who look
on you as good food. But there is another way, and that is to wear
armour. Then you can frighten your enemy, or at least prevent him from
eating you. Some fish, like the Trunk Fish, (p. 52, No. 6), are covered
with bony plates, jointed together like armour. Spines and prickles are
a commoner defence.
The little Stickleback of our ponds wears sharp spines, and knows well
how to use them. Even the terrible Pike will not swallow such a
dangerous mouthful unless driven by hunger.
Sea-fish are the most hunted of all living things. From the day they
leave the egg, enemies lurk on all sides to gobble them up. The weak
ones are eaten, and none of them has the chance to die of old age! So we
find a defence of spines and prickles worn by many sea-fish. Spines on
the fins are the commonest, and no doubt help to keep away enemies; but
some fish go one better than that, and wear a complete suit of spines.
The Porcupine-fish, as his name tells us, is one of these. He is a small
fish, living in warm seas. No doubt he has many enemies, eager to meet
him and eat him. But, when they see this little fish puff out his sides
like a balloon, and when pointed spines rise up all over the balloon,
they think better of it! They leave him alone; and the Porcupine-fish
goes back to his usual shape, the spines lying flat until wanted again.
He is sometimes called the Sea-hedgehog or Urchin-fish, and well
deserves his name.
Many of the Skates or Rays wear terrible spikes. The Starry Ray (p. 52,
No. 7) is not easy to handle, dead or alive, for he has spines all over
his body. The Thornback is another ugly fellow of this family, having
spines on his back and a double row of them down his tail. Fishermen are
careful to avoid the lash of this armed tail. The Sting Ray shows us
still another weapon. At the end of its long tail it has a horrible,
jagged three-inch spike. As this fish likes to bury itself in wet sand,
bathers sometimes tread on it. In a flash the tail whips round! A
poisonous slime covers the spike, causing great pain to the unlucky
bather.
Several poisonous fish are common near our coast. You may have seen the
one called the Great Weaver, also its small cousin, the Sting Fish. The
Weaver is dreaded by fishermen; for the spines on its back fin, as well
as the one on its gill-cover, cause poisoned wounds. They are grooved,
to hold a very poisonous slime.
Some fish have the power to kill their prey, and stun their enemies, at
a distance! Instead of a spiny defence, they are _armed with
electricity!_ The best-known sea-fish of this sort is the Electric Ray,
also called the Cramp Fish or Torpedo (_see_ p. 48). It is a clumsy fish
about a yard long, and very ugly. Being too slow to catch its swift prey
in fair chase, it stuns them with an electric shock, and then eats them.
The electric power comes from the body of the Ray; if it wishes it can
send a deadly shock through any fish which ventures near. Without chance
of escape, it is at once stunned, and falls helpless.
We come now to some formidable dangers of the deep--big strong fish, so
well armed that they roam the seas without fear. On page 52 you see a
picture (No. 2) of the Saw-fish, one of the Shark family. It is a large
fish, and carries a big saw on its head, with which it stabs sideways at
its prey.
Imagine, if you can, a Shark about fifteen feet long and weighing a ton
or so. Now suppose the top jaw of this monster to be drawn out into a
hard, flat blade six feet in length. Then suppose there are sharp ivory
teeth, one inch apart, fixed on each side the blade, and you have an
idea of the Saw-fish. This strange Shark is said to be as strong as it
is fierce. It kills its prey by tearing them open with side blows from
its sharp, two-edged saw. Its big mouth is fitted with a great many rows
of needle-like teeth.
The Sword-fish wears a different weapon--a lance instead of a saw. He is
not a Shark, but a cousin of the beautiful Mackerel. This warrior of the
deep is more dreaded than the Saw-fish, and braver than any Shark. His
speed in the water is marvellous; it makes him safe from attack. He
carries in front of him a terrible weapon, and all sea-creatures hasten
from his path as fast as they can.
You may have seen the Sword-fish in a museum. There is a fine one in the
London Natural History Museum, where there is also a "sword" from one of
these fish, driven eighteen inches into the solid oak of a ship. The
Sword-fish never thinks twice about attacking, no matter if his enemy is
ten or twenty times as large as himself. He sees a Whale, and, like a
flash, hurls himself at it, stabbing his sword as deep as it will go
into the Whale's side. With a twist of his body the sword is wrenched
free, only to be driven savagely in again.
EXERCISES
1. Mention three ways in which sea-creatures try to escape their
enemies. 2. How do the Sting-fish and Sting Ray defend themselves? 3.
What is the Saw-fish like? 4. How does the Sword-fish attack its prey?
LESSON IX
THE FISH OF OUR ROCK-POOLS
The pools left by the falling tide have many an interesting thing to
show us. There are living creatures in plenty, besides the pretty weeds,
shells, and other objects. Shrimps, Prawns and Crabs abound in the
rock-pools and shallows, with anemones and shellfish of all kinds. In
the rock-pools we shall also find the interesting little fish whose
story we glance at in this lesson. Of course there are baby flat-fish,
and large fish too, along the shore. But these are only visitors. The
real rock-pool fish are those which live their lives there.
Some of them are tiny things, two or three inches long. With quick
movements like Shrimps they dart away as you approach. They have a way
of hiding under weeds and rocks, being very clever at "hide-and-seek,"
and knowing all the dodges. But, by using a net, you will soon capture a
few of them. Then you can put them in a small pool and examine them; or
even keep them in an aquarium, giving them clean sea-water, seaweed, and
the small shrimps on which they feed.
[Illustration: PIPE-FISH AND FLUTE MOUTH]
In our lesson on fish-nurseries we saw how the Sea-stickleback, Sand
Goby and Pipe-fish cared for their eggs or young ones. These three fish
are often to be found by the shore. As you look into the clear and still
waters of a pool you may see a Pipe-fish getting its dinner. This funny
creature looks more like a pencil swimming than a fish. It may be a foot
in length, but its body is no thicker than a pipe-stem!
[Illustration: FISHES (No. 2).
1. John Dory.
2. Rock Cod.
3. Sand Eel.
4. Small Pipe Fish.
5. Cuckoo-Wrasse.
6. Angler.
7. Whiting.
8. Gattorngine.
9. Sapphirnal Gurnard.
10. Three-bearded Rockling.
11. Red Gurnard.
12. Pipe Fish.
13. Bass.
14. Red Mullet.
15. Turbot.]
It has very long jaws. They are quite useless, however, being fastened
together! At their tip is an opening, though a very small one, and that
is the mouth of the Pipe-fish. Of course, with such a mouth, the fish
cannot bite its prey, and so has to suck in small creatures and swallow
them. Its method of hunting them is strange. It stands on its head, as
it were, takes in a mouthful of water, and spurts it out at the sandy
bed of the sea. This stirs up the small living things, which are at once
swallowed by the Pipe-fish.
We have already seen how the male Pipe-fish carries his eggs in his
"pocket." Another curious thing is his suit of armour. Instead of
scales, he has hard plates all over his body. Very often you may see
young Pipe-fish among Sprats and "Whitebait" in the fishmonger's shop.
Most of the little shore-fish are either Gobies or Blennies. No doubt
they have to avoid the sharp eyes of Gulls and Cormorants, for they are
very anxious not to be seen. Some of these rock-pool fish do not mind
being out of water for hours at a time. In every way Nature has fitted
them for their life between sea and shore. They have cousins in warmer
seas which love to come ashore at times. This is how a traveller
describes one of these foreign Gobies:--
"Though they are fish, and breathe by gills, they have a passion for the
land, and during the daytime may always be seen ashore, especially where
the coast is muddy. They bask in the sun, and hunt for food, raising
themselves on their fleshy fins.... When pursued, they take great
springs, using their tails and fins for the purpose; and if they cannot
escape into the sea, they will dive down the burrow of a land-crab, or
dash into a bunch of mangrove-roots." They are very wary, having eyes
like swivels, to turn in all directions.
[Illustration: A BUTTERFLY BLENNY]
The Spotted Goby, as we have already noticed, makes a nest under a
shell, and guards it until the eggs hatch. Two other Gobies are quite
common in the pools of our south coast--the One-spot Goby and the
Two-spot Goby. The back fin has the one spot, or two spots, from which
they get their name. Though they are such mites, they have sharp teeth,
as you may already know if you have caught them with your fingers!
These lively little fellows are not very easy to catch! They have a
cunning way of hiding amid sand and rock, and are coloured to suit such
places. One strange thing about the Gobies is their trick of anchoring
themselves to a stone.
You may wonder what kind of anchor they can use. It is a simple matter,
however. The fins on the stomach are pressed together to form a little
disc. This acts as a strong sucker, much like that of the Sucking Fish
(p. 43). If the Goby wishes to stay still in one place, it presses its
sucker to a stone; then it cannot be washed away by the ever-moving
water.
In the Blenny family we find big, ugly fish as well as pretty little
ones of strange shapes and lovely colours. There are several kinds of
small Blennies in our rock-pools. The Eyed Blenny, or Butterfly Blenny
is not very common along our shores, but may be seen now and again. It
is only a few inches in length, with eyes like jewels, a kind of tuft
over each eye, and a pretty spot on its tall back fin.
It will live quite well in a glass tank of sea-water; someone who kept
many interesting fish says of this Blenny:--
"Our little Butterfly Blenny was not often to be seen. It was using an
old whelk shell for a nursery. In this broken old shell the dainty fish
was able to hide, and was so nervous that we seldom saw it. But we
placed some food near the hole in the shell, and were rewarded by the
sight of the Butterfly's head, and its lovely eyes, each with a little
movable tassel above it."
[Illustration: A SMOOTH BLENNY]
Hidden under weed and stones is another small brownish fish of the
shore, the Gunnell or Butter-fish. You may turn it out of its snug
hiding-place, but you will have a hard task to catch it, even in a small
rock-pool, and, once caught, it slips through your fingers like an eel.
Its body is eel-shaped, with a narrow fin on the back, and covered with
a layer of slime. It well deserves the name of Butter-fish.
The eggs of this strange little fish are rolled into a mass by the two
parents. By curling their long, slimy bodies around the eggs, a
closely-packed ball is the result. This precious ball of eggs is then
taken care of, and guarded by the two fish. In this nursery both the
father and mother fish take their share as guardians.
EXERCISES
1. Name three rock-pool fish. 2. Describe the Pipe-fish. 3. How does the
Sand Goby anchor itself? 4. In what ways are these rock-pool fish so
well fitted to live in such places?
LESSON X
SOME CURIOUS FISHES
Now and again that queer fish called the Sea-horse is found by our
coast; a little brown fish, with bluish-white spots and lines on the
sides and tail. But Sea-horses are common in warmer seas, in the banks
of seaweed where they love to dwell. You would never guess that these
curious creatures were fish.
The shape of the head, and the curved neck, remind you of a horse. It is
also rather like the knight of the chess-board; or it may make you think
of the dragon of the fable; but, really, the Sea-horse is like nothing
on the earth, or in the waters. Nature has given it a special pattern of
its own.
Sea-horses use their twisty tails as monkeys do, clinging to the seaweed
with them. They swim along slowly, in an upright position. Every now and
then they seem to be falling forward on their noses, and pull themselves
up again, only to begin falling a moment after. It is fun to see them
play hide-and-seek among the weed in an aquarium. Some Sea-horses are
like floating scraps of torn weed; this, of course, hides them from the
eyes of enemies.
[Illustration: SEA-HORSES]
They have no teeth, but a long mouth like a pipe; so you can be sure
they eat only the smallest sea-creatures. To add to his odd look, the
Seahorse moves his eyes in a comic fashion. One eye may roll round and
look at you, while the other gazes forward.
As if this were not strange enough, he surprises us again. Mr. Sea-horse
turns himself into a living nursery. He carries the eggs about with him,
in a special pouch of skin! You will remember that the Pipe-fish also
carries the eggs in his pocket, as it were. So you will not be surprised
to hear that these two quaint fish belong to the same family.
We will leave the funny little Sea-horse, and look at a very different
fish--the Sunfish. This remarkable fish often reaches a good size; even
near our coast big ones are caught now and again, and in warmer seas,
where they are often killed for the sake of the oil they contain, big
fellows of half a ton are quite common.
This Sunfish has a peculiar shape. It looks as if it had once been an
immense fish of the usual fish shape, but someone cut off the head and
shoulders, and placed a short fin where the rest of the body had been.
Above and below there is a long pointed fin. The mouth is very small,
and has no real teeth; so the Sunfish lives on small prey, such as the
young of other fish, or small shell-fish.
Far away from land these strange Sunfish are met with, asleep near the
surface, with the back fin showing above water. They roll along lazily,
not unlike big cart-wheels. The top and bottom fins are for balancing
and guiding the body, which is moved forward by the fin which frills the
back part of this odd fish.
[Illustration: GLOBE FISH]
In the fishmonger's shop you may sometimes see that ugly monster of the
deep, the Angler-fish, or Fishing-frog. Now and again he finds his way
into the fishermen's nets; and is also caught on the lines, for he is so
greedy that he will snap at a hooked fish. Rather than let go of his
prey, he will be drawn to the surface. Then he is knocked on the head,
and thrown into the boat with the other fish.
Being slow and clumsy, the Angler-fish cannot chase his prey, so gets
his dinner by fraud. Nature has given him a fishing line and a bait! He
has long spines on his head, so beautifully joined to the bones of the
head that they can wave to and fro very easily. At the tip of the front
spine there is a loose, shining strip of skin--that is the bait. Now,
all anglers know how a fish is lured by a shining bait. The Angler-fish
seems to know this too. He buries himself in the wet mud and sand at the
bottom of the sea. Then he waves the long spine, so that the shining tip
glistens as it shakes in the water, until a fish swims up to see what it
is all about. A sudden snap, and that inquisitive fish is inside a huge,
toad-like mouth, well furnished with rows of sharp teeth. The
Angler-fish puts his catch in his pocket, and begins fishing again, for
he is never satisfied. His pocket is a loose bag of skin in the throat.
This bag is always examined by fishermen who capture the Angler, for it
may contain a nice big Plaice or Sole, worth money in the market.
There are Angler-fishes in every ocean, and some live in the very
deepest parts. In those black depths the little waving "bait" would not
be seen. So it is made to shine, like a bluish spark moving to and fro
over the cold black slime of the sea-bed.
Down in those awful deeps it is for ever dark, and freezing cold, There
is no day or night, summer or winter. No plants can live there. Yet in
that strange, still world there are numbers of living things, though we
know very little about them. There are weird Crabs, blind Lobsters, and
fish terrors such as are never seen elsewhere.
In that darkness you would think that eyes would be of no use, but some
of the deep-sea fish have great black owl-like eyes. Others are quite
blind, or have eyes like pin-points. Some of them make their own light,
glowing with rows of little lamps on their bodies, each like the lamp of
the glow-worm of our country lanes. Blue, red, and green these lights
are, but no one can tell you their real use, or why they are so
coloured. The blind fish feel their way with long feelers, stretched out
like the threads of a web.
[Illustration: THE FISHING FROG.]
As there are no plants down there, these strange fish must live mostly
on one another! And here is a puzzle, for some of them have great big
bodies, but small heads and tiny mouths; others have bodies like
ribbons, but large heads and huge mouths, and some are such gluttons
that they swallow fish twice their own size! This sounds absurd, but it
is true. Their mouths gape open like trap-doors, and their stomachs are
made to stretch, to hold their huge meals! There are other terrors of
the deep with such big teeth that they cannot shut their mouths. No
doubt the sea holds yet other weird fish which no man has seen.
EXERCISES
1. In what ways is the Sea-horse so different from most other fish? 2.
In what ways are the Sea-horse and Pipe-fish alike? 3. How does the
Angler-fish catch its prey? 4. Mention a few strange facts about the
deep-sea fish.
LESSON XI
THE GARDEN OF THE SEA
For many centuries men were puzzled over those strange growths in the
sea--Corals and Sponges. Were they to be classed as animals or as
vegetables? It was by no means an easy question to answer.
Corals, with their pretty colour, and their stems and branches growing
up from the sea-bed, were said to be shrubs, but they were as hard as
rock, said some people, so how could they be vegetables? The reply to
this was, that the Coral became hard as soon as it reached the air.
Then, of course, it was found that Coral was as hard under water as
above it, and the question was still unanswered.
Sponges, too, were thought to be sea-plants for many, many years; though
some people even said that they must really be made of hardened
sea-foam! The Sponge took its place in the vegetable kingdom, then it
was moved to the animal kingdom, and back again.
This went on for long years. Then, by careful watching, it was found
that the Sponge is an animal. True, it is a very lowly member of the
great kingdom of animals, yet it is one, and not a plant.
Like all other animals, the Sponge animal must eat, and its way of doing
so is rather strange. If you look at any ordinary washing-sponge, you
notice a great many very small openings and some larger ones amongst
them. It is through the smaller holes, or pores, that the Sponge gets
its supply of food. When it is alive, and in its own home, there is a
current of water always passing through its and the Sponge depends on
the food which the water brings. Now, if you could watch this
water-current, you would see that it rushes into some of the holes, and
out of others; it has a certain path to follow. It enters the small
pores, or openings, of the Sponge, and goes along narrow canals, and is
then led into larger ones. Finally, it rushes out again through those
large openings we noticed. We may compare it with traffic coming into a
city by many narrow streets, then passing into broader roads, and at
last out again by big main roads.
[Illustration: CUPS AND SOLID SPONGES]
[Illustration: _Photo: A. F. Dauncey_. SEA FURZE]
How does the Sponge animal cause this current; and how is it made to
follow a certain path?
The narrow canals in the Sponge are lined with lashes, or tiny hairs, so
very small that you can just see them through a microscope. Now the
secret of the wonderful water-current is a secret no longer. As long as
the Sponge lives, these little lashes are always moving, always lashing
the water along in one direction. They cause it to follow its proper
course, through and through the Sponge, and out again into the sea. On
its way it loses the tiny scraps of food which it contains, and carries
away any waste stuff out of the Sponge.
You will have noticed that there are various kinds of Sponges in the
market; some are large and flat, others small and cup-shaped; some are
soft, and others rather hard. They are all somewhat horny and elastic.
This "spongy" material is the skeleton of the Sponge animal, cleaned and
dried for your use. Some kinds of Sponge would tear your skin if you
tried to use them, for they have a hard skeleton. It is made of lime,
and sometimes of flint, which the Sponge obtains from its food. Of
course we use only those sponge-skeletons which are soft; but the
cheaper kinds do often contain little flinty needles.