THE STICKLEBACK 87 
The Ten-spined Stickleback (Gastrosteus pungitius) 
Fin FoRMULA. TEETH. 
First Dorsal: no membrane, ro spines. Villiform, in both jaws. 
Second Dorsal: g rays. 
Pectoral: 11 rays. 
Ana/: 1 spine, 9 or Io rays. 
Ventral: 1 spine, 1 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. 
