TROPICAL AQUARIUM FISHES 15 
THE SILVERFIN 
Of all the native fishes tried in the aquarium by the writer the 
Silverfin (Notropis analostanus) 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 aquarium, their sleek bodies 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. 
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Fic. 57. THE SILVERFIN 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. 
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