FisJi Study 



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1 ne johnny darter likes a swift-flowing brook. 



THE JOHNNY DARTER 

 Teacher's Story 



'^We never tired of watching the little Johnny, or Tessellated darter {Boleosonia 

 nigrum) , although our earliest aquarium friend, [and the very first specimens showed us 

 by a rapid ascent of tlie river weed hew 'a Johnny could climb trees,') he has still many 

 resources which we have never learned. Whenever,' we try to catch him ivith the hand 

 we begin with all the uncertainty that characterized our first attempts, even if we have 

 him in a tivo-qtiart pail. We may know him by his short fins, his first dorsal having 

 but nine spines, and by the absence of all color save a soft, yellowish brown, which is 

 freckled with darker markings. The dark brown on the sides is arranged in seven or 

 eight W-shaped marks, below which are a few flecks of the same color. Covering the 

 sides of the back are the wavy markings and dark specks which have given the name of 

 the "Tessellated Darter;" but Boleosoma is a preferred name, and zve even prefer 'boly' 

 for short. In the spring the mules have the head jet black; and this dark color often 

 extends on the back part of the body, so that the fish looks as if he had been taken by the 

 tail and dipped into a bottle of ink. But nith the end of the nuptial season this color 

 disappears and tJie fish regains his normal, strawy hue. 



His actions are rather bird-like; for he xvill strike attitudes like a tufted titmouse 

 and he flies rather than swims throtigh the water. He will, with much perseverance, 

 push his body between a plant and the sides of the aquarium and balance himself on a 

 slender stem. Crouchijig catlike before a snail shell, he will snap off a horn which the 

 unlucky owner pushes timtdly out. But he is also less dainty and seizing the anitnal 

 by the head, he dashes the shell against the glass or stones uiUil he pulls the body out or 

 breaks the shell." — David Starr Jordan. 



The johnny darters are, with the sticklebacks, the most amusing little 

 fish in the aquarium. They are well called darters since their movements 

 are so rapid when they are frightened that the eye can scarcely follow 

 them; and there is something so irresistibly comical in their bright, saucy 



