These have peculiar flat bodies, greatly compressed, but in a direction different from the flat Fishes of the Ray family. In the case of the Raia, the body is flattened horizontally, but in the Fishes belonging to this family the bodies are compressed laterally—like that of the well-known Flounder. The head of the Fishes of this group are not symmetrical; the two eyes are placed on the same side, and the two sides of the mouth are unequal. These strange flat Fishes are always turned upon their side, and the side turned towards the bottom of the sea is that which has no eye. It is to this habit of swimming on their side that they owe their popular name of side-swimmers.
They advance through the water very slowly compared with the motion of other Fishes. They can ascend or descend in the water very quickly, but cannot turn to the right or left with the same ease as other Fishes. This property of rapidly rising or sinking in the water is more useful to them, as they spend the greater part of their time at the greatest depths, where they draw themselves along the sands at the bottom of the sea, and often hide themselves from their enemies.
These flat Fish have an oblong body, the side opposite to the edges being furnished with shaggy, soft hairs; the nose is round and nearly always in advance of the mouth, which is twisted to the felt side, and furnished with teeth only on one side, while the eyes are on the right side. The Common Sole is from eighteen to twenty inches in length. It is brown on the right, and whitish on the opposite side. Its flesh has a very delicate flavor, and it is said to acquire a finer taste by being kept for several days.
The Turbot resembles a lozenge in general form. Its under jaw is more advanced than the upper one, and is furnished with many rows of small teeth. One side is marbled brown and yellow, and the other is white with brownish spots and points; the long rows of soft fins are yellow with brown spots. The true Turbot has always been the special delight of the epicure, and fabulous sums are said to have been paid at different times, in order to secure a fine specimen.
The Flounders and Plaice inhabit the northern seas of Europe. They are also found along our coasts; the Flounders are fresh water Fishes of small size, abundant in the Thames and many other rivers; and they are desirable for food, although not so delicately flavored as the Turbot. The Common Plaice attains the length of ten or twelve inches. It is brown, spotted with red or orange. On the eye-side of the head are some bony tubercles, but the rest of the body is smooth.
The Dab is distinguished from the other flat Fish by having very hard scales on its body, and the Halibut has the distinction of being the largest of this class of flat Fish. It is occasionally caught in the seas of Northern Europe and Greenland, measuring seven feet, and weighing from three to four hundred pounds. The body of the Halibut is more elongated than that of the Plaice or Flounder, and its jaws are armed with strong and pointed teeth.
The natives of Greenland fish for the Halibut with an implement which they call gangnaed. It is composed of a hempen cord five or six hundred yards in length, to which are attached about thirty smaller cords, each furnished with a barbed hook at the end. The larger cord is attached to floating planks, which act as trimmers, indicating the place of this destructive contrivance. At the end of twenty-four hours these lines are drawn from the water, and it is not unusual to find five or six large Halibut caught on the hooks.
Another mode of catching this and other flat Fish is to spear them on their sandy beds. No rule is laid down for this method of fishing; in some places it is carried on successfully by means of a common pitchfork. In other places a fine spear is used for the purpose—very long and with sharp prongs.