THE COMMON MACKEREL. 



DESCRIPTION, SIZE, ETC. 



The genus Scomber, of which the common mackerel {S. scomhrus) is 

 the leading representative, is distinguished from related genera of 

 scombroid fishes of the Atlantic coast (JlJ/j:**', the frigate mackerels; 

 Gymnosardaj the little tunnies; T/i»?m».s% the great tunnies; Sarda^WiQ 

 bonitos, and iSconiberomorus, the Spanish mackerels and kingfish) by 

 the small size of the species, by the absence of a median keel on each 

 side of the caudal peduncle, by a short spinous dorsal fin having 9 to 

 12 spines, by the pattern of coloration, and by a number of other 

 characters. 



The body of the mackerel is fasiform and but little compressed later- 

 ally. The standard length is 3^ times the depth. The caudal peduncle 

 is slender, with a small keel on either side. One-third of the total 

 length without tail consists of the head. The eye is rather small, its 

 diameter being only one-fifth the length of the head. The mouth is 

 large and armed with a row of small slender teeth in each jaw. There 

 are two dorsal fins, the anterior containing li spines and the posterior 

 12 ra.ys, following which are 5 finlets; the formula of the anal fin is 1 

 spine, 11 rays, and 5 finlets. The scales are very small, numbering 

 several hundred along the lateral line. The color is dark blue above 

 and white below. About 33 dark wavy vertical streaks mark the back. 



The common mackerel closely resembles the other species of the same 

 genais found on both the Atlantic and Pacificcoasts, namely, the bull's- 

 eye, chub, or thimble-eye mackerel {S. colias), but is separated from it 

 by the absence of the air-bladder, more dorsal spines, smaller eye, and 

 somewhat different markings. 



The length of the full grown mackerel is 17 or 18 inches, but fish a 

 little over 20 inches long, and weighing upward of 3^ or 4 pounds, are 

 occasionally taken. The average length of the market catch is about 

 12 inches. Such a fish weighs from three fourths of a pound to a pound. 



Small mackerel are known among the fishermen by several names, 

 such as " spikes," " blinkers," and " tinkers." Spikes are the smallest 

 ca«ght by the commercial fishermen; they are 5 or inches long and 

 are ~> to 7 months old. Tinkers are under 9 inches in length and are 

 supposed to be about two years old. Blinkers are intermediate in size 

 and age. Maturity is probably attained in the fourth year. 



DISTRIBUTION, MOVEMENTS, ABUNDANCE, AND SPAWNING. 



This species iidiabits the North Atlantic Ocean. On the American 

 coast its range is from Cape Hatteras to the Straits of Belle Isle. On 

 the European coast the fish is found from northern Norway, in latitude 



F. C. K. isyr — u 209 



