Foraging Habits 



375 



larvae there is developed both before and behind its 

 border a considerable array of combs and rakers. In 

 use the head is thrust forward, and these are dragged 

 backward across the surface that supports the growth 

 of diatoms and other algae. 



The principal carnivores of the rapids are the nymphs 

 of stoneflies (see fig. 1 1 1 on p. 204) and a few small 

 vertebrates. Among the latter are the insect-eating 

 brook salamander Spelerpes, and a number of small 

 fishes, such as darters, dace and minnows. 



