Fish Culture in Inland Waters 307 



food of adults was largely composed of several kinds of fishes and 

 some crayfish, 86 per cent of the food being fishes. 



Pearse ('15) shows that young blackbass from about two up to a 

 little less than two and a half inches fed upon small larvae, insects, 

 amphipods and Entomostraca ; and that from twenty-seven speci- 

 mens from about two inches up to about four inches, averaging a 

 little over three inches, the diet was composed of 14.2 per cent 

 fish, 31.2 per cent insect larvae, 38.6 per cent insects, 3.8 per cent 

 amphipods, 2.5 per cent Entomostraca, and 1.6 per cent plant fibre. 



Moore ('20) says that Chironomid larvae are among the most 

 important single items in the dietary of the young of this species. 



5. Black Crappie. Bean says : " This small bass occurs in streams 

 as well as in lakes and ponds, and is a very good game fish. Its 

 average weight is about a pound. Its food consists of worms, small 

 crustaceans, and fishes." 



" Fingerlings are available at the same time, and may be planted 

 in the same way, as blackbass." 



Concerning this species Pearse ('19) gives the following summary 

 of his observations made in Lakes of Wisconsin in 1916. 



" I. This paper attempts to compare the habits of the black crap- 

 pie with those of the perch, with the purpose of ascertaining why 

 the former is better suited to shallow lakes and the latter to deep 

 lakes. 



" 2. The food of the crappie consists chiefly of insects, particularly 

 immature stages, entomostracans, amphipods, and fishes. 



"3. In spring amphipods and entomostracans are the chief items 

 in the dietary. During the warmer months crappies feed largely on 

 insect larvae, pupae, and adults, and on cladocerans. In winter adult 

 crappies take little or no food in Wisconsin lakes. 



" 4. Feeding is most active at night, or in early morning and even- 

 ing. 



" 5. Young crappies feed for the most part on copepods, clado- 

 cerans, insect larvae, and amphipods. During their first season they 

 increase rapidly in size until the temperature of the water falls to 

 about 4 degrees C, but grow very little during the winter. 



" 6. The rate of digestion in the crappie is about the same as in 

 the perch, but less food is eaten at a time and feeding is more delib- 

 erate. 



" 7. In southern Wisconsin lakes, crappies spawn after the water 

 temperature has reached 19 to 20 degrees C, or more ; while the 

 perch spawn earlier, when the temperature is 8 to 9 degrees C. 



" 8. During the winter crappies remain in deep water and are 

 comparatively inactive. In spring they come inshore and remain 

 in shallow water throughout the summer. 



" 9. Crappies have few parasites when compared with perch. 



" 10. Though perch are more abundant than crappies in the 

 shallow lake investigated, they do not attain large sizes. Crappies 

 are large, and, considering their larger sizes, relatively abundant. 



"11. Crappies are better suited to shallow lakes than perch, 



