TROPICAL AQUARIUM FISHES 



193 



SALVINIA 



Of the small floating aquatics Salvinia is one of the best. The heart- 

 shaped leaves with bristle-like growth on the upper surface seem like 

 bits of velvet connected by a thread. The roots are naturally long for 

 the size of the plant but fishes usually eat them down to about half length, 

 which interferes with a full development of size. In the greenhouse 

 where they have a moist atmosphere and no interference they develop 

 with amazing rapidity. The variety illustrated. Salvinia natcns, is native 

 to Europe and is the form commonly used in aquaria and pools. 



Although it is claimed that neither Salvinia nor the common wild 

 Duckw^eed perform any oxygenating function, the author and others 

 have many times seen aquaria completely covered with either of these 

 plants and, with no other plants in the aquarium, the fishes were getting 

 along perfectly well. 



FROGBIT 



Hydrocharis morsus-ramc, requiring the same conditions as Trianea 

 bogotensis, deserves more attention than it is receiving. Of very 

 pretty appearance when in flower, readily olitained from dealers, there is 



Fig. 147. Frogbit (Life size) 



