ANIMALS WITH JOINTED LEGS— THE ARTHROPODS 



195 



Courtesy General Biological Supply house 



Courtesy General Biological Supply House 



Courtesy General Biological Supply House Photo by Winchester 



Fig. 13.10. Small Crustacea. Upper left : fairy shrimp. Upper right: Cyclops. Lower 

 left : water flea, Daphnia. Lower right : pill bugs. 



Otherwise the accumulation of barnacles greatly reduces the speed of 

 the ships. 



Water fleas are aquatic vertebrates which are only about one tenth 

 of an inch long, and since they do not bite, they appear to have little 

 economic importance. They breed very prolifically, however, and fur- 

 nish an important source of food for many animals including important 



