202 Fresh Water Aquarium 



greatly; in some it is dark greenish brown, 

 in others bluish black on the back, changing 

 to silvery white on the belly. Throat and 

 breast have a pink tinge, turning, in the 

 case of the male during mating time, to a 

 very vivid red, which extends over the larger 

 part of the belly. The eyes are of a greenish 

 color. Characteristic, and responsible for 

 the name — Three-spined Stickleback — are 

 three sharp thorns which take the place of 

 the forepart of the dorsal fin. 



Placed in the aquarium in March, a pair 

 of these fishes will soon begin to make 

 preparations for the spawning. To facili- 

 tate this a fairly dense vegetation should be 

 provided. The male selects a fitting place 

 for the nest, usually in a cluster of aquatics 

 near the bottom. He then carries to the nest 

 site fine roots and parts of plants which he 

 has torn off for the purpose of constructing 

 the nest, which he now proceeds to do in a 

 very neat and ingenious way. To prevent 

 the nest from being removed he secures the 



