TROPICAL AQUARIUM FISHES 75 



THE SILVERFIN 



Of all the native fishes tried in the aquarium by the writer the 

 Silverfin {Notropis analostamis) stands out as one of the most satis- 

 factory. For aquarium purposes the male fish should be selected. The 

 ends of their fins are of a whitish, phosphorescent color from May till 

 September. Darting around in the acjuarium, their sleek lx)dies overcast 

 with a pale steel-blue, and sides laced with black edgings of scales they 

 make a most attractive appearance. Two of them will often indulge in 

 what appears to be a game of tag, during which they will chase each 

 other around a short circle, producing the effect of a pinwheel. 



Fig. 57. The Silvkrfin or Satinfin (Slightly enlarged) 



A 50-gallon aquarium, with plenty of open space, containing about 

 fifteen adult male silverfins is most fascinating. 



They are very hardy, tame, and will eat any prepared food. Harm- 

 less to other fishes. 



They may be caught in the open reaches of the fresh tidal portion of 

 the Delaware as well as its upland tributaries. 



Silverfins have been kept in aquaria for several years, but care should 

 be exercised to cover with a screen to prevent their leaping out. 



The Darter 



The darters have no swimming bladders and are therefore consider- 

 ably heavier than water. They move along the bottom in jerky motions 

 somewhat like hopping. When in reach of their prey they make a short 

 leap. Although this seems to be short of the object they always succeed 

 in getting what they go after. One would imagine them to have a long 

 tongue like a frog, moving with invisible rapidity. There is something 

 quaint and droll about the darters. The majority of them cannot stand 

 warm water. 



