The electric eel. There are several species inhabiting the water, and which have the power of producing electric discharges by certain portions of their organism. The best known of these are the Torpedo, the Gymnotus, and the Silurus, found in the Nile and the Tiger.
In the Surinam eel, the electric organ goes the whole length of the body along both sides. It is able to give a very severe shock, and is a formidable antagonist when it has attained its full length of 5 or 6 feet.
1. The fertilised egg, shed in the gravelly bed of the river.
2. The embryo within the egg, just before hatching. The embryo has been constricted off from the yolk-laden portion of the egg.
3. The newly hatched salmon, or alevin, encumbered with its legacy of yolk (Y.S.).
4 and 5. The larval salmon, still being nourished from the yolk-sac (Y.S.), which is diminishing in size as the fish grows larger.
6. The salmon fry about six weeks old, with the yolk fully absorbed, so that the young fish has now to feed for itself. The fry become parr, which go to the sea as smolts, and return as grilse.
In all cases the small figures to the right indicate the natural size.