A great many fishes are very odd to look at, and this is one of the oddest. Imagine a fish with an almost circular flattened body, with five brown bands edged with white running round it, huge round eyes, enormous triangular fins both above and below the body, a broad tail, which looks as if it were tied in by a piece of ribbon at the base, and a mouth drawn out into a long slender beak! And this fish has a habit which is even odder still, for when it sees an insect sitting on a leaf which overhangs the margin of the sea, it takes careful aim, squirts a drop of water at it from out of its long beak, and nearly always succeeds in knocking it into the water below!
This fish lives in the Indian and Polynesian seas, and is sometimes kept as a pet by the Japanese, who amuse themselves by fastening a fly to the end of a piece of stick and holding it over the bowl in which the fish is living, in order to see it knocked off its perch by a pellet of water.
The Cod
Throughout the northern seas the cod is found, and in some parts it is taken in immense numbers. The largest and finest of all, which sometimes weigh more than one hundred pounds, come from the banks, or shallows in the sea, off the shores of Newfoundland, but very fine ones have been taken elsewhere; and extensive cod-fisheries are maintained in the North Pacific, near Alaska.
Cod are mostly captured by means of long lines, each about forty fathoms in length, to which a number of smaller lines are fastened at intervals. The hooks are placed on the side lines, and are generally baited with whelks, and then the long lines, or trawls, as the fishermen call them, are anchored in shallow parts of the sea where codfishes, halibut, and the like abound. Each boat carries about eight miles of these lines, with nearly five thousand hooks, so that the work of baiting, lowering, and raising them is very heavy indeed. The fishing takes place in the winter, and the boats are generally out in all weathers for several months at a time.
One would think that with so many boats engaged in cod-fishing, each with so many miles of line, nearly all the cod in the sea would soon be caught. But to offset this, a single cod in a single year will often lay eight or nine million eggs, so that notwithstanding the immense number of these fishes which are taken, they still seem as plentiful as ever.
Flatfish
The so-called flatfishes, such as the sole, the plaice, the flounder, and the dab, form an interesting group. Although we call them "flat," we ought really to call them "thin," because what we always consider as the back of a sole is really one of its sides, and what seems to be the lower surface is the other side.
The explanation is this: when these fishes are quite small, they swim upright in the water, just as other fishes do, and drive themselves along by means of their tails. But when they are about a month old a strong desire comes over them to go and lie down on the mud at the bottom of the sea, and then three remarkable things happen.
First their color changes. Up till now, both sides of their bodies have been nearly white. But if a white fish were to lie down on dark-brown mud, of course it would very easily be seen, and most likely would very soon be devoured by one of its many enemies. So as soon as the little fish lies down at the bottom of the water its upper surface begins to grow darker, and before very long it exactly resembles the hue of the surrounding mud. Or if the fish should lie upon sand, as the plaice does, then its upper surface becomes colored like the sand. So as long as it keeps still its enemies may pass quite close to it without noticing it.