Our common Stickleback--"Tiddler," or "Red-throat," as boys call him--builds a nest in ponds. He has a seaside cousin, the fifteen-spined Stickleback, who is also a nest-builder. This little fish is fairly common round our coasts, living in weedy pools by the sh.o.r.e, where it devours any small creature unlucky enough to come near. It is about six inches long, this sea Stickleback, with a long snout, and its body is very thin near the tail.
To build his nest, this little fish chooses a quiet corner, then gathers pieces of green and purple seaweed. He takes the pieces in his mouth, pushing them about until the shape is to his liking. Having got his nursery to the right size and shape, the little builder next fastens it together. How can he do this? What mortar can he find in the sea? It is quite simple. He uses threads, which come from his own body. He swims round the nest, again and again; and, each time, a thread is spun, binding the clump of weed into a safe, tight nest for the eggs. When the task is done there is a weed-nursery about the size of your fist. Now all is ready for the eggs to be laid by the female Stickleback. You would expect them to be kept in a hole amid the nest, would you not?
Instead of that, they are tucked a few here, a few there, in the weed.
Then the father Stickleback mounts guard. Woe betide any small fish looking for a dinner of Stickleback eggs! The gallant little sentry will rush at him, with spines as stiff as fixed bayonets, ready to do battle to the death. When the young are hatched out he still keeps guard. They are not allowed out of the nursery for some time. The watchful parent forces them back if they try to wander out into the perils of the sh.o.r.e-pool.
[Ill.u.s.tration: _Photo: A.F. Dauncey_. SKATE"S EGG CASE]
Let us look at another nest-builder--the Sand Goby, or Spotted Goby, He is common enough in the pools at low tide, but not easy to find. You can look at him, yet not see him! For he takes the same colour as the rocks and sands of his home. Amid the glinting lights and shadows of his rock-pool, with a background of sand, rock, and weed, this little fish is nearly invisible. Of course it is a dodge, and a useful one, to escape the eye of the enemy!
Perhaps you will not think the Spotted Goby so clever at nest-building as the Stickleback. He likes to use a "ready-made" house, whereas the Stickleback finds his own "bricks and mortar." In the pools of the sh.o.r.e there is no lack of houses to let, the empty homes of sh.e.l.l-fish are there in plenty. So the little Goby, when nesting time comes, hunts round for the empty sh.e.l.l of a c.o.c.kle lying with its hollow side to the sand.
This sh.e.l.l is to be used as the roof for the nursery. The Goby"s next task is to make a hole beneath the sh.e.l.l. He sets to work and, by scooping out the sand, makes a hole about as large as a marble. To keep the sand from tumbling in, he smears the hole with slime, which soon binds hard like mortar. Now the nursery is nearly ready; but a pa.s.sage-way is made, pa.s.sing under the edge of the sh.e.l.l, and then, to make things quite safe, the whole roof is covered with sand: it then looks more like a b.u.mp in the sand than a fish-nursery.
The female Goby enters the nest, and leaves her eggs in it; and then the little father fish is left in charge. He rests on the sand, near the entrance. When the little ones appear, he seems to think he has done his duty. So away, he swims, not staying, like the father Stickleback, to guard the youngsters. Again we see that the father, and not the mother, is the builder and nurse.
[Ill.u.s.tration: CORALS OF MANY KINDS.]
That very strange creature, the Pipe-fish, has the most peculiar nursery of all. He uses no building material! No made-up nest of weed or sand for him! No, he prefers to carry his eggs in his pocket. To be more exact, there is a small pouch under his body, and there the eggs are kept until they hatch. Meanwhile, the Pipe-fish goes about his affairs in the pool as if nothing particular had happened. You will see more about this funny little fish when we come to our lesson on "The Fish of our Rock-pools."
EXERCISES
1. What are the eggs of the Skate and the Dog-fish like? 2. How does the Sea-stickleback build his nest? 3. Where would you find the Sand Goby, the Pipe-fish, and the Sea-stickleback? 4. How does the Sand Goby build its nest?
LESSON V
THE OGRE OF THE DEEP
The ogre of the fairy-tale is bad enough, but, for evil looks, the Octopus is worse still. With his tough, brownish skin, k.n.o.bbed like the toad"s back, his large staring eyes, his parrot"s beak, and ugly bag of a body, the Octopus is a horrid-looking creature. Add to this eight long arms twisting and writhing like snakes, and you have an idea of the most hideous inhabitant of the deep.
Then, like the ogre, the Octopus lives in a cave, and goes forth at night to claim his victims. He tears them to pieces, and returns to his dark cavern when daylight comes.
Before seeing how this ugly monster lives, eats, breathes and fights, we must know something of the way he is made. In the first place, it may surprise you to know that the Octopus"s body is made on the same plan as that of the snail. The ogre of the ocean and the Garden Snail are second cousins! Their family name--_mollusc_--means _soft-bodied._
But there are such numbers of molluscs that we split them up into different orders, just as a big school is split into cla.s.ses. The Octopus belongs to an order of molluscs with a long name, which only means _head-footed._ Why is he called head-footed? The snail, as you know, has one broad foot under its body. The foot of the Octopus is divided into eight strips. These long strips are set round his head, hence the name head-footed. Because there are eight of these long feet he is named _octo-pus_ or eight-feet.
The feet--or arms, or tentacles, as they are called--are joined at their base by a skin. It makes a sort of webbing. In the centre of this is a h.o.r.n.y beak, usually of a brownish colour. It is just like a parrot"s beak, only of thinner and lighter stuff. There are two parts to it, the top one curving down over the lower one. Behind this beaked mouth is a hard, rasping tongue. On each side of the head is a big, staring eye; and behind the ugly head is the ugly body, like a bag.
The Octopus breathes by means of gills. Water enters through a big hole under the head, pa.s.ses over the gills, and out again through a _funnel_, or _siphon_. Now the Octopus can make good use of this siphon. Sometimes he is attacked, and wishes to "make himself scarce." So he sends the water rapidly through the siphon; the force is enough to jerk him quickly backwards, his "arms" trailing behind.
The Octopus and his relations have another dodge as well. They possess a bag of inky fluid. By mixing this ink with the spurt of water from the funnel, the Octopus leaves a thick cloud behind him. The enemy is lost in this dark cloud, while the Octopus darts safely away.
[Ill.u.s.tration: THE OCTOPUS--A MONSTER OF THE DEEP]
Having no armour to protect him, and no sh.e.l.ly home like that of the snail, the Octopus is an easy prey to large fish, Seals and Whales. So this trick of shooting backwards, hidden in a cloud of ink, must be of great use. Soldiers and sailors use clouds of smoke to baffle their enemy in battle. The Octopus uses clouds of ink.
Sharks, Conger Eels, and Whales are able to fight the Octopus and eat his soft body; but small fish and Crabs keep away from the ogre if they can. This is not easy, for he hides away under rocks, watching with his great eyes for pa.s.sing prey. If anything comes near enough, out flicks a long, tapering, snaky arm, and holds the victim tight.
Down the inside of each arm are nearly three hundred round suckers. Each one acts like those leather suckers with which boys sometimes play. Once fixed, it is nearly impossible to unloose them, without chopping or tearing the arm to pieces. First one and then another sucker takes hold, and the wretched victim is drawn up to the ogre"s beak, with no chance of escape.
When one sees the grasping power of even a small Octopus, it is easy to believe that a large one would be a dangerous enemy. The strongest swimmer would stand no chance: those clinging arms could hold two or three men under water.
[Ill.u.s.tration: WHALING.]
Luckily, the Octopus has no wish to attack people. It is not fierce. But to the Crabs it must seem an awful ogre. I once watched an Octopus on the lookout for food. It had its lair between two rocks, its twining arms showing outside, its eyes and body in the shadow. Along came a Crab, scuttling near the rocks. He spied the ogre, at once stopping and raising his claws as Crabs do, like a boxer ready to fight. The Crab having strong pincers, and a good suit of armour, I expected to see him fight for life. But no! Like poor Bunny chased by the dreaded Stoat, the Crab gave in as soon as the ogre flicked him with an arm. The suckers gripped him fast and, still holding up his claws, he was drawn into the den of his dreadful enemy.
Although armed with a beak, the Octopus seems not to use it against the Crab. He prefers to pull the poor Crab to pieces with his strong arms, and then to pick up the crab-meat with the hooked beak. When full-fed, he retires to his den; he sometimes pulls sh.e.l.ls and stones over the entrance, and rests within until hungry.
In this strange order of molluscs there are dwarfs and giants. One kind is never more than two inches long, others are vast monsters. The Octopus is big enough and ugly enough to make one shudder to see him, but the real ogre of the deep is the Giant Cuttle-fish, beside which the Octopus is a tiny mite.
These Giant Cuttles have ten arms, two of them being very long. The Octopus"s body is round, like that of a fat spider, while the Cuttle has a long body. The Cuttle has many sharp claws on its arms, besides numbers of big, strong suckers. It holds and tears its prey at the same time. Its staring eyes are like big black lanterns on each side of the head. The head twists this way and that, so that nothing escapes the glare of those horrible eyes.
Lurking in the dark depths of the sea, these Giant Cuttles wait for large fish, Crabs, or even their own relations, to come near. Like hideous, gigantic Spiders, they are the terror of the ocean caverns.
They are so large that they have few enemies to fear. Indeed, it is surprising that any animal dares to attack such a monster, but that other giant, the Sperm Whale, dives deep to the home of the Cuttles, purposely to attack and eat them.
The Sperm Whale _must_ attack these big creatures in order to get enough food. He has such a huge, barn-like body to fill, that only these big Cuttles will satisfy him. Whale-hunters sometimes catch a glimpse of terrific combats between these giants of the deep. The Sperm wins the battle, for he is nearly always found to contain great pieces of the ogre"s arms.
Although the Octopus and the Cuttle are related to the Snail and Whelk, they have no sh.e.l.l. Their bodies are naked. Neither do they grow a backbone, or skeleton; but, inside the body, the Cuttle has a plate of chalk, which you may find on the sh.o.r.e. Some kinds have a long strip of transparent substance, like a large feather. Fishermen use the smaller kinds of Cuttle as bait. You will find it quite easy to cut out the "beaks" and "bone" for yourself, or the fishermen will not mind saving them for you.
EXERCISES
1. What is the meaning of the words "mollusc" and "octopus"? 2. How does the Octopus capture its prey? 3. How does the Octopus escape its enemies? 4. What creatures prey on the Cuttle and Octopus?
LESSON VI
THE WHALE
Now and again Whales are washed up on our coasts, and then we can see how huge is this strange monster of the deep. It is by far the largest of all living animals. Once on the land it is quite helpless; it cannot regain its home in the waters, and slowly dies. It is shaped like a fish, and its home is in the sea, so no wonder it has often been called a fish.
If by chance the Whale is held under water, it drowns. It has no gills, like those of the fish, to take air from the water; it is a mammal, a creature that must breathe the free air just as other mammals. Nature is full of surprises. And here she surprises us with a mammal most marvellously fitted to live a fish-like life.
The Whale dives to great depths in search of food, and stays under water for a long time. But it is forced to rise again, and breathe at the surface. To do this, it need not put its head and mouth out of water, for its nostril is at the top of the head.
As the Whale forces used-up air from its nostril--or "blow-hole," as it is called--it mixes with water; this causes a jet or spout of water to rise some distance into the air. The blow-hole is closed by a stopper or valve, opening to let the air in or out, but closing to shut out the water.
Some of the Whale family are enormous, and some are small. A large Sperm Whale may grow to be ninety feet long, and its weight would be nearly two hundred tons! This huge creature would look like a deep barge in the water.
These Sperm Whales love to swim in herds, or schools. As many as three hundred have been seen in one school, old "bulls" and "cows," and their young ones swimming together far out at sea. It has been noticed that they all spout, or breathe, at the same time, and then dive to great depths. The old ones seem to know that their babies cannot stay under water as long as a full-grown Whale can, and they all rise at the same time. These youngsters may be nearly thirty feet long; but they gambol like so many kittens, twisting and turning over and over, and throwing themselves into the air. Most Whales are happy creatures, enjoying their roving life in the free ocean.
You can well imagine that a Whale as big as a barge needs huge dinners.
We should not be far wrong if we guessed that he would need about a ton of food every day. Where is he to get all that food? It is said that he feeds mostly on the Cuttle-fish, that giant cousin of the Octopus, who haunts the dim caverns of the deep. The Sperm is of enormous strength, and is as fierce as he is strong. Otherwise he would not dare to face the awful, clinging arms of the Cuttle, that ogre of the deep sea.
The Sperm Whale has a great, blunt head, a huge mouth, and a throat large enough to swallow a man. His clumsy-looking head contains oil, so does the deep layer of blubber with which his body is covered.