TEOPICAL AQUARIUM FISHES 71 



THE ROSY-SIDED DACE 



Lcuciscus vandoisidus 



One of the less known, but very attractive aquarium fishes is the 

 Rosy-Sided Dace. The general color is silvery to green. A nearly black 

 lateral line runs the length of the body, and below this on the males is 

 a long patch of red, starting from the edge of the gills, as shown in 

 illustration. This varies in intensity from day to day, and is brightest 

 from February until September. As these fishes dart about the aquarium 



^^# ^\^" ^^^ 

 Fig. 52. Rosy-Sided Dace {Life sice) 



the flame-like appearance of the red patches is most striking. Even when 

 not in color there is an interesting bronze-green effect to the scales at 

 the lateral Hne. This is always visible by reflected light, and seems to 

 show mostly at night. H the light is turned on them at night they show 

 very little red color, but in a few minutes it is quite plain. 



The Rosy-Sided Dace is a large minnow and takes kindly to the 

 aquarium and is perfectly harmless, but unless plenty of room is pro- 

 vided it will slowly decline. Found in clear cool brooks, from the foot- 

 hills of the Alleghenies to the Carolinas. 



THE BLACK-NOSED DACE 



Rhinicthys atronasus 



The Black-Xosed Dace is one of the best of our native fishes for 

 aquarium purposes. Found in abundance in small swift-running streams 

 of the Delaware Valley, it is an extremely active swimmer and not easily 

 caught unless cornered in a small pocket. From constant swimming 

 against the current it has developed some specialized kind of balance, 

 so that when introduced into the still water of the aquarium, the forward 

 part of the body continually drops so a level position is only main- 

 tained by an effort. This condition disappears in a few weeks and a new 

 equilibrium becomes established. 



