336 THE AQUARIUM 



them, especially in the spring. They are exceedingly de- 

 structive when at large, being very persistent in the devour- 

 ing of the eggs and fry of other fishes. Their breeding 

 habits, however, are most interesting and may easily be 

 observed in the aquarium. When the season for reproduc- 

 tion is at hand, the male selects a proper site among the 

 aquatic plants, and there builds a fairy mansion of tiny 

 bits of plant material, cemented together with a glutinous 

 secretion from an abdominal gland. There are two en- 

 trances, and after he has induced the female to enter and 

 deposit her eggs he proceeds to fertilize them, and then 

 stands guard. The female should now be removed, to save 

 her from the attacks of her mate, who keeps up a continual 

 fanning, forcing a current of water over the eggs. After 

 about two weeks his zeal will be rewarded by the appearance 

 of a great crowd of little ones. He is the best of fathers 

 until the young begin to move about the aquarium, when 

 he no longer recognizes them as his own and must be re- 

 moved. The young feed at first on protozoans, and later 

 will take small Crustacea and prepared foods. 



Adult sticklebacks are too pugnacious to be kept with 

 other fishes. They are hardy, and should be fed chiefly 

 on animal food, although they will take artificial prepara- 

 tions. 



Tropical Fishes 



We come now to the fishes of the tropical and subtropical 

 waters of Asia, Africa and America. They exist, of 

 course, in almost endless variety, and comparatively few are 

 known among aquarists. Their cultivation has been carried 

 on for years in Europe, and more especially in Germany, 

 where great proficiency in their care and propagation has 

 been attained. It is only during recent times that they have 

 received attention from American fish-keepers, but their 



