FOREST, LAKE, AND RIVER 



for the mackerel) may be known by the little fin- 

 lets on the lower and upper edges of the peduncle 

 (the fleshy part of the tail) and by a small keel on 

 either side of it. It has a large mouth which is 

 armed with small slender teeth on each jaw, and 

 the scales are extremely minute, numbering several 

 hundred along the central and horizontal line of 

 the body. The color is dark, somewhat steely- 

 blue above the median line and white below, with 

 about thirty-five dark, vertical, wavy streaks along 

 the back. 



Small mackerel have several names among com- 

 mercial fisherman : the smallest caught, about five 

 or six inches in length, and supposed to be five to 

 seven months old, are called " spikes ; " those 

 under nine inches in length, and presumably two 

 years old, are known as " tinkers," and the name 

 of " blinkers " is applied to those that are inter- 

 mediate in size and age. A full grown mackerel is 

 so called when it reaches the age of four years, and 

 a length of seventeen or eighteen inches ; but speci- 

 mens have been taken over twenty inches in length, 

 having a weight of nearly four pounds ; the aver- 

 age length of the marketed fish, however, seldom 

 exceeds twelve inches. 



The migratory movements of the mackerel, and 

 the causes thereof, are not clearly understood ; but 

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