304 CIVIC BIOLOGY 



11. One or two of the most wonderful curiosities of fish natural his- 

 tory : a nest of sticklebacks, " nothing short of marvelous " (Mornaday), 

 or a paradise fish with his nest of bubbles ; or exchange with coast 

 schools and devote one of the large aquaria to artificial sea water and 

 marine forms. 



Classification and species. About as many different kinds 

 of fislies as of birds are known to science (13,000, Galloway), 

 but more than four times as many fishes as birds are found 

 in the inland and marine waters of North America (3263 

 species). 1 Any list (published by your state fish commission 

 or by the United States Bureau of Fisheries) giving the dis- 

 tribution of fish and fish eggs for the preceding year will 

 contain about fifty of the more valuable food and game 

 species, and from this w^e may choose the most instructive 

 types for study.'-^ 



Ponds as balanced aquaria : foods and overstocking. The 

 work with aquaria may be made to help in understanding 

 how to keep park waters and reservoirs in good condition. 

 Lack of proper balance results in fouling the water, and 

 is accompanied with offensive odors and appearance. The 

 fishes die, beginning with the more overcrowded or more 

 sensitive kinds, and ending with the catfishes, w^hich can live 

 in fairly wholesome mud. Probably in most such cases the 

 prime reason why the fishes die is because they lack proper 



1 Jordan and Evermann, Descriptive Catalogue of North American Fishes, 

 8313 pages, 392 plates. "The work has been carefully devised to be of no 

 use whatever to anyone save an ichthyologist" (Hornaday). 



2 The list recommended for pond culture is as follows : black basses 

 (small-mouthed and large-mouthed), crappie, calico, rock, and warmoutli 

 basses, the bluegill sunfish, and the cattish, or bvdlhead (either Ameiurus 

 nebulosus or A. n. marmoratus, a variety known in the South as the marble 

 cat). Strong local prejudice and lack of outward beauty are against the 

 humble catfish, but for edibility Dr. Jordan has placed it above all the 

 basses, perches, and pikes, and just below the trout, salmon, and whitefish. 

 The bluegill is the only sunfish recommended for use by the Bureau of 

 Fisheries, " and it is believed to be the finest pond fish available for private 

 culture." — Jonssox and Stapletox. loc. cit.. p. 18. 



