BREEDING HABITS OF RAINBOW DARTER. 



37 



yellow bar beneath ; a row of oblique brown dashes separates 

 this from the grey of the lower half of the fin. 



The young males are described (Jordan and Everman, 1896) 

 as variously marked. Those sexually immature look like the 

 females. The fully developed males, when not breeding, show 

 the general pattern already described for the females but have the 

 transverse bars on the posterior part of the body of bluish tint 

 and have pale reddish orange spots between these. Varying 

 amounts of peacock blue may be found on the cheeks and the 

 ventral, anal, and caudal fins. The second dorsal is made con- 

 spicuous by two broad bands which extend the length of the fin ; 



Fig. I. The male Etheostoma cceruleum Storer, as he turns to display his ventral 

 fins to another male. Photograph of a living fish slightly retouched. 



the upper is of dull brick red while the lower is of peacock blue. 

 The first dorsal is much like that of the female but with colors 

 more intense since peacock blue takes the place of the dull grey 

 of the outer margin. Over the belly and throat are patches of 

 salmon or pale orange. 



According to Jordan and Everman (1896), this Etheostoma is 

 a Mississippi Valley form and the most abundant darter of the 

 Ohio Valley. During most of the year these fish lurk among 

 the stones and gravel of the small streams they inhabit. Their 

 habitat is swift water. They are found at the lower ends of the 

 rapids where the water enters the pools along the course of the 

 stream, and also among the stones of the rapids themselves. 



Living thus in exposed places the darters are very alert. If 

 one approaches the stream cautiously, so as to remain concealed 



