THE STICKLEBACK 87 



The Ten^spined Stickleback [Gastrosteus pungitius) 



Teeth. 

 Villiform, in both jaws. 



Fin Formula. 

 First Dorsal : no membrane, i o spines. 

 Second Dorsal : 9 rays. 

 Pectoral : 11 rays. 

 Anal : i spine, 9 or 10 rays. 

 Ventral : 1 spine, i ray. 



The ten-spined stickleback resembles the three-spined in 

 habits and disposition, being strongly gregarious, and, at the 

 same time, intensely pugnacious, but it is not nearly so 

 numerous as the other, at least in Britain. The colour of 

 the males, however, is not nearly so brilliant as in the other 

 species, the breeding dress in England being plain black. It 

 has from nine to eleven dorsal spines, which can be erected 

 at will. In other respects the general features are much the 

 same in both fishes. The Scandinavian traveller and sportsman 

 Lloyd has described the industry of fishing for sticklebacks 

 in Sweden. It begins in November, and the method is for 

 two men to go by night in a boat to some bay where ripples 

 betray the presence of a shoal. One of the fishers holds 

 aloft a torch, the other plies a small-meshed landing-net, and 

 the boat is sometimes filled two or three times in a single 

 night. The fish are boiled for oil to be used as an illuminant, 

 the produce averaging about half a gallon of oil to the bushel. 



