168 



NATIVE AQUARIUM FISHES 



free from the parasite should be chosen where possible. The usual length 

 is from two to three inches. 



They have been known to survive in the aquarium for several years. 



THE STICKLEBACK 



Froebel, the founder of 

 the Kindergarten idea, wrote 

 delightfully of the Stickle- 

 back. Perhaps that accounts 

 for its being fairly well- 

 known, because it is seldom 

 kept as an aquarium fish- 

 anyhow not in the United 

 States. This is a pity, because 

 its breeding habits are unique. 

 The male is the smaller, 

 and during courtship (at least 

 in the four-spine variety) the 

 ventral fins become a fiery red. 

 He selects a group of plants 

 suited to his peculiar needs. 

 From his body is exuded a 

 substance which he attaches 

 to the plants and proceeds to 

 draw it into a silk-like thread 

 which he continues to wrap 

 round and round until he has 

 constructed a wonderful little 

 nest, such as shown in the il- 

 lustration. An opening for 

 water circulation is left in the 

 side. The female deposits eggs 

 in the nest and there her do- 

 mestic duties end. Father 

 Stickleback assumes entire charge, his principal duty being to keep up a 

 circulation of water between the eggs. This he does by alternately blow- 

 ing through the top of the nest and the side opening. Eggs hatch in 

 about a week and for approximately ten days more he guards them jeal- 

 ously against all possible enemies, regardless of size. 



Sticklebacks prefer eating live daphnia or chopped clams or oysters. 

 They are not well suited to live with other small aquarium fishes. 



Fig. 140. Sticklebacks and Their Nest 



