FISHES OF THE GULF OF MAINE 167 



these being present, however, along the bases of the anal and dorsal fins and on the 

 caudal keels. There are no true scales. The most diagnostic character is that 

 there are usually 9 spines on the midline of the back (from 7 to 12 have been counted) 

 in a continuous row from just in front of the pectoral to the dorsal fin, leaning 

 alternately to one side or the other and set in a slightly zigzag line. The spines are 

 slightly curved; wider at the base than at the tip; fairly uniform in size, about one- 

 half to one-third as long as the height of dorsal fin; and each with a small triangular 

 fin membrane at the base. They may be depressed to lie in a shallow mid-dorsal 

 groove. Each ventral fin is represented by a stout curved spine thicker and longer 

 than the dorsal spines. The dorsal and anal fins (the former stands above the 

 latter) are similar in form, tapering from front to rear, the anal preceded by a single 

 stout recurved spine. The tail fin is square-tipped. 



Size. — Large adults are seldom more than 3, usually 2 to 2%,, inches long. 



Color. — Usually dull olive brown above, the upper sides faintly barred or 

 blotched with darker. The belly is silvery, the pubic and thoracic regions often 

 black. The color varies with the season of the year, with the state of sexual matu- 

 rity, and with the color of the bottom on which it lives, those on dark mud being 

 darker and those on bright sand paler. All become more brilliant during the 

 breeding season when reddish tints appear under the head, the belly turns greenish, 



Fig. 72. — Nine-spined sticklebnck (Pungitius pungilius) 



and black dots develop here and there over the entire body. The male has also 

 been described as assuming a rosy tint beneath. 



General range. — This is one of the most widely ranging of northern fishes, 

 occurring in both the fresh and salt waters of the northern parts of both hemi- 

 spheres from northern Scandinavia to France on the European coast, from Arctic 

 seas south to New York along the American coast, and westward to Saskatchewan 

 and Alaska. 



Occurrence in the Gulf of Maine. — This stickleback occurs all around the shores 

 of the Gulf of Maine from Nova Scotia and the Bay of Fundy to Cape Cod, but so far 

 as we can learn it is confined to the brackish creeks in salt marshes, where large 

 numbers may often be taken in company with the mummichogs that swarm in 

 such locations, and where it is to be found throughout the year, and to fresh water. 

 In the Gulf of Maine it seldom or never ventures out into the salt waters of the 

 open sea. About Woods Hole, too, it is distinctly a brackish and fresh-water fish. 



Habits. — Hardly touching our Gulf proper, we need only note that its mode of 



life and feeding habits are much the same as those of its three-spined relative next 



to be considered (p. 16S), that it is similarly destructive to the spawn and young of 



other fish, and similarly pugnacious. Probably this stickleback spawns early in 



102274—25 + 12 



