207 



tlie strong currents and eke out a living where their larger cousin, 

 tlie yellow perch, would perish. There are many interesting facts 

 which may be learned from the Johnny darters when kept alive in 

 an aquarium. When not actually moving in the water, do the 

 Johnnies rest on the bottom of the jar or remain suspended in the 

 middle apparently resting on nothing as the other aquarium fishes 

 do ? When a fish remains still in the middle of tlie jai', he does so 

 because he has a well developed air-bladder to help buoy him up 

 and when a iisli dies it is the air-bladder whicli causes liim to turn 

 over and rise to the top. Now if the Johnnies always rest on 

 the bottom of the jar when not swimming and if one happens to die 

 and does not rise to the top we may know that, if he has an air- 

 bladder at all, it is only a rudimentary one. It would be interesting 

 also to find out for ourselves if a Johnny darter can really " clindj 

 trees" (1 mean by trees, of course, the water plants in the aqua^ 

 rium jar), or if he can perch upon the branches like a bird. 



The Minnows. 



All the small fishes of the brooks are called minnows, or more 

 often " minnies," by the boy fisherman. The boy believes that they 

 grow into larger fishes. This is not true. The minnows are a dis- 

 tinct group of fishes and, for the most part, small ones. They do 

 not grow to be bass or pike or sunfishes or anything else but min- 

 nows. Some of the minnows, however, are comparatively large. 

 Two of these are the Greek Chub (Fig. 105), and the Shiner (Fig. 

 105). The chub is the king of the small brooks, being often the 

 largest and most voracious hsh found in such streams. His common 

 diet probably consists of insects and worms, but if very hungry he 

 does not object to eating a smaller fish. During the spawning 

 season, which is springtime, the male chub has sharp, horny tuber- 

 cles or spines developed upon the snout. We are able to recognize 

 the Creek chub by means of a black spot at the front of the base 

 of the dorsal fin. 



The shiner or red-fin has much larger scales than the chub. The 

 back is elevated in front of the dorsal tin, giving him the appear- 

 ance of a hilmp-back. His sides are a steel-blue with silvery refiec- 



307 



