606 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



half of the last pelvic soft ray. Tubercles are also present on the 

 distal seven-eighths of all elements of the anal fin. 



Two males of E. proeliare (USNM 165959, Mississippi, Big Black R., 

 April 8) have tubercles on all elements of the anal fin, on the tip of 

 the first pelvic soft ray, and on the entire length of pelvic soft rays 

 2-5. Seventeen males (28-32 mm. standard length) from the Red 

 River, Louisiana (USNM 172733), taken January 12, lack tubercles 

 as do over 40 females. Seven other males in this collection (30-32 

 mm.) have tubercles on the distal half of pelvic soft ray 3 and a few 

 scattered tubercles on the distal end of the second and fourth soft 

 rays. Two males have a few tiny tubercles on the fourth anal ray. 

 Thus, the tubercles seem to form first on the middle soft rays of the 

 pelvic fin, spread to the other pelvic soft rays, and then develop on the 

 anal fin rays. 



Tubercles are present on males of E. microperca from as early as 

 April 16 (UMMZ 81525, Michigan, Kalamazoo R.) until as late as 

 July 10 (UMMZ 67927, Michigan, Big Wolf Cr.). They are absent 

 on specimens taken from July 19 to December 21 (USNM), but few 

 specimens are available from January through March. Tubercles 

 develop fh'st and remain for a longer period of time on the pelvic fin 

 rays than on the anal fin rays. The maximum development J have 

 observed is on males taken May 3 (UMMZ 73144 and 73158, Michi- 

 gan, Au Sable R.). Tubercles are present on the entire length of the 

 ventral surfaces of all the pelvic elements and on the anal spines. I 

 have not seen specimens with tubercles developed on any of the anal 

 soft rays as I have in the other two species of the subgenus. This 

 poor development of tubercles is probably correlated with the 

 northerly occurrence of E. microperca. A similar situation has also 

 been shown m Percina {Percina) caprodes, Etheostoma {Oligocephalus) 

 spectabile, and E. (Hololepis) fusiforme fusiforme. Petravicz (1936) 

 failed to find tubercles on E. microperca, and Winn (1958b, p. 172) 

 reported them on only the pelvic fins. E. microperca spawns in an 

 approximately vertical position on plants. The male is mounted on 

 the female's back with his tubercidate cuplike pelvic fins clasped over 

 her back and his tuberculate anal fin in contact with her sides (Winn, 

 1958b, fig. 4). 



Summary 



Breeding tubercles are now known for 48 species in five genera of 

 the Percidae. Tubercles in the Percidae are mainly distributed 

 laterally and function primarily in facilitating contact between the 

 male and female during the spawning act. Tubercles may have a 

 stimulatory function, especially in the species that have them on the 

 undersurface of the pelvic fins. Breeding tubercles are of value in 

 classification at two levels. 



