BREEDING TUBERCLES IN FISHES — COLLETTE 



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maximum tubercle development (CU 38055 and CU 38127, Georgia, 

 Toccoa R., June 7) tubercles are present on most ventral scale rows 

 posterior to the pelvic fins and below the lateral line. A few tubercles 

 are present on some of the lateral line scales. The modified mid- 

 ventral scales have up to three tubercles per scale. This, with 

 P. uranidea and P. caprodes, is one of the few darters in which tubercles 

 are present on these scales and is the only species in which there is 

 more than one tubercle per scale. If the midventral scales function 

 in a manner analagous to the breeding tubercles, the possession of 

 both tubercles and the modified scales seems unnecessary. It will 



Figure 2. — Male of Percina (Ericosma) evides showing the distribution of breeding 

 tubercles (USNM 44433, Indiana, Tippecanoe River, May 16, S3 mm. SL). 



be interesting to learn how these structures function in the courtship- 

 spawning act. Tubercles are present on some rays of the ventral 

 half of the caudal fin. The cephalic pores of the preoperculoman- 

 dibular and infraorbital canals are sites for small tubercles. These 

 tubercles extend onto the chin beside the pores of the anterior portion 

 of the preoperculomandibular canal, as in Etheostoma {Hololepis) 

 gracile and E. (H.) zoniferum. Tubercles are present on some of the 

 branchiostegal rays, a condition unique among the Percidae, although 

 known for some Cyprinidae. Small scattered tubercles are present 

 on parts of the opercle. 



Among the Percinae, only Percina {Imostoma) uranidea has a 

 tubercle distribution which approaches that of P. evides. Eoman- 

 ichthys and Zingel in the Luciopercinae have large numbers of tubercles 

 on the head, concentrated on top. 



Tubercles are absent on specimens of P. crassa in several March 

 and April collections (UMMZ), although the males have greatly 

 enlarged testes and the females are filled with large eggs. Eight 

 males of P. palmaris taken on March 31 (CU 17328, Georgia, Talking 

 Rock Cr.) appear to be in fuU breeding color, but they lack breeding 

 tubercles, although fleshy ridges similar to those in Etheostoma 



