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?