216 



THE OPAL SEA 



Coloring of 



school 



fishes. 



Protective 

 colorings. 



Changeable 

 colorings. 



a boat and crew almost as readily as over the 

 line of a net. 



The school fishes are by no means of uniform 

 coloring, and yet in a general way they are al- 

 most all of them alike in being blue-green or 

 olive-colored on the backs, silvery on the sides, 

 and whitish on the bellies. It has been said 

 that this coloring was given them for conceal- 

 ment and protection. The bird looking down 

 upon them from above sees only the shading 

 of their backs into the dark of the water; the 

 shark looking up from beneath sees their light 

 bellies and sides blending with the light coming 

 from above. For a similar reason perhaps the 

 flounder flattened in the sand was given a back 

 that matches the sand as exactly as a tree toad's 

 skin the branch he is resting upon. This gift 

 of adaptation of color would seem something 

 more than accident or coincidence. Many fish 

 in the sea have tones and shades that conceal, 

 and, what is more remarkable, many have the 

 power of changing their colorings at will. This 

 has been long known, and recently quite con- 

 clusively proven, in the aquariums. Changing 

 the backgrounds of the tanks has resulted in 

 many fishes changing their hues to correspond. 



But whatever the color, or for whatsoever 

 purpose given, it is generally beautiful color. 



