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.