R-2 

 RIFFLES 



A shallow rapids in an open stream where the 

 water surface is broken into waves by wholly 

 or partly submerged obstructions. Riffles 

 usually support a wider variety of bottom 

 organisms than other stream sections. (See 

 Pools) 



RITHRON ZONE 



Stream reach at higher elevations characterized 

 by rapid flow, low temperature, and high 

 dissolved oxygen levels. (See Potamon Zone ) 



ROUGH FISH 



Those species of fish considered to be of 

 poor fighting quality when taken on tackle; 

 e.g., carp, gar, suckers, etc. These fish 

 are considered undesirable in most situations, 

 Most species in the group are more tolerant 

 of widely changing environmental conditions 

 than game fish . 



