2 86 ELEMENTARY ZOOLOGY 



" anglers " the first spine of the dorsal fin hangs over the 

 mouth. It has at its tip a fleshy appendage which serves 

 as a bait. Little fishes nibble at this, the mouth opens, 

 and they are gone. In the deep seas, many fishes are 

 provided with phosphorescent spots or lanterns which 

 light up the dark waters, and enable them to see their 

 prey. In storms these lantern-fishes sometimes lose their 

 bearings and are thrown upward to the surface. 



In general the more predatory in its habits any fish is 

 the sharper its teeth, and the broader its mouth. Among 

 brook-fishes the pickerel has the largest mouth and the 

 sharpest teeth. It has been called a " mere machine for 

 the assimilation of other organisms. ' ' The trout has a 

 large mouth and sharp teeth. It is a swift, voracious, and 

 predatory fish, feeding even on its own kind. The sunfish 

 is less greedy and its mouth and teeth are smaller, though 

 it too eats other fish. 



As means of escape, most fishes depend on their speed 

 in swimming. But some hide among rocks and weeds, 

 disguising themselves by a change in color to match their 

 surroundings. Others, like the flounders and skates, lie 

 flat on the bottom. Still others retreat to the shallows 

 or the depths or the rock-pools or to any place safer than 

 the open sea. Some are protected by spines which they 

 erect when attacked. Some erect these spines only after 

 they have been swallowed, tearing the stomach of their 

 enemy and killing it, but too late to save themselves. 

 Again in some species the spines are armed with poison 

 which benumbs the enemy. Sometimes an electric battery 

 about the head or on the sides gives the biting fish a 

 severe shock and drives him away. Such batteries are 

 found in the electric rays or torpedo, in the electric eel 

 of Paraguay, the electric catfish of the Nile, the electric 

 stargazer and other fishes. 



Some fishes are protected by their poor and bitter flesh. 



