LAMPREYS AND FISHES 



Like their relatives, the common pickerels hang stately and 

 quiet in the shadows of floating leaves, painted into the back- 

 ground by the olive brown and olive green network which 

 covers all but the pale undersides of their bodies. Now and 

 then they dart forth as swift as arrows, and clutching a hap- 

 less fish or a frog, take it down at a gulp and resume their 

 motionless watch. 



Size. — Up to 24 inches. 



Distribution. — Maine to Florida, west to Arkansas; com- 

 mon. 



Sticklebacks — Gasterosteidce 



The stickleback family is a tribe of fishes between two and 

 three inches long which have a row of sharp upstanding spines 

 on their backs. They live among the weeds of small streams 

 and are famous both for their pugnacity, and their industry in 

 nest-building. The sticklebacks are generally greedy and 

 quarrelsome; they will attack others, eat their eggs, and keep 

 themselves generally busy with other fishes' affairs. 



Brook stickleback, Eucalia inconstans. — The brook stickle- 

 back has four free spines and a fifth spine which is attached to 

 the dorsal fin and is marked with indistinct dark bars across 

 its back (PL XVIII). In spring the male's back is almost 

 black, lightening to yellow beneath; at the same time the 

 female is olive colored, mottled and dotted with brown. 



The nests of sticklebacks look like birds' nests and like 

 them are made of plant stems, but these nests are stuck to- 

 gether by a fluid from the kidneys of the male; the females 

 take no responsibility in its building. 



Each nest is a delicate sphere about three-quarters of an 

 inch in diameter, with a hole on one side. It is made of fine 

 fibres, plant stems, and filaments of algse and attached to a 

 plant stem or a submerged twig. Against a background of 

 leaves and plant stems these little nests are well nigh undis- 

 coverable except by a chance happening. The male stickle- 



339 



