FAMILY CENTRARCHIDAE 



241 



Figure 4.7. Northern rock bass, Ambloplites rupestris rupestris, 5 inches long. 



Lake Superior drainage in Minnesota, though Greene (1935) found it 

 in this drainage in Wisconsin. 



The rock bass spawns from late May until early July on gravel beds 

 in streams or on shallow sand bottoms in lakes. Some of the females 

 examined from lakes near St. Paul contained as high as 11,000 eggs, 

 though most of them contained about 5000. 



This fish reaches a weight of over 2 pounds. It is a good game fish and 

 has considerable value as a pan fish, though the flesh sometimes has a 

 muddy flavor. It bites readily on grasshoppers, worms, and minnows, 

 and at times it will rise to a fly. It travels in schools, and once a school 

 is located the angler can often catch his limit in a short time. 



GENUS Pomoxis Rafinesque 



This genus contains two species of crappies, both of which are found 

 in Minnesota and neighboring states. Both species have many names. 



WHITE CRAPPIE (White Bass) 

 Pomoxis annularis Rafinesque 



The shape of the white crappie (Figure 48) is about the same as that 

 of the black crappie, though in some specimens the head is more dished 

 and the back is not as high. The anal fin of the white crappie has less 

 conspicuous dark mottlings than that of the black crappie. The color is 

 silvery, more or less mottled with dark green. Usually there are dark 

 bars on the sides, particularly in young ones. This species is usually 

 lighter in color than the black crappie, with which it is easily confused. 

 It may be often distinguished by the dorsal spines, which usually num- 

 ber 6, as compared with 7 or 8 in the black crappie. However, some in- 



