BREEDING TUBERCLES IN FISHES — COLLETTE 597 



and the male mounts her with his pelvic fins clasped over her dor- 

 sum and his taU pressed tightly against hers (Linder, 1958). 



The same tubercle pattern was found on males of E. whipplii 

 taken between February 29 (UMAIZ 177250, Arkansas, lUinois 

 Bayou) and April 12 (TU 17771, Texas, Neches R.) . At the maximum 

 development observed (UMMZ 155103, Kansas, Crooked Cr., 

 April 9; and UMMZ 177160, Arkansas, Illinois Bayou, April 3), 

 tubercles begin one-third of the way from the pelvic fin origin to 

 the anal fin origin, extend onto 5-7 rows of scales per side just anterior 

 to the genital papilla, on 2-3 rows above each side of the anal fin 

 base, and onto 6-8 midventral rows of caudal peduncle scales. Speci- 

 mens taken earlier (UMMZ 177250, February 29) and later (TU 

 17771, April 12) lack tubercles above the anal fin base and on the 

 ventral surface of the caudal peduncle. 



The tubercle pattern of E. caeruleum seems to be the same as that 

 of E. radiosum and E. whipplii. Leslie W. Knapp, who is reviewing 

 the systematics of E. caeruleum, has kindly given me his data on 

 tubercles of this species and has permitted me to examine the speci- 

 mens with the best developed tubercles. Poorly developed tubercles 

 are present in 15 collections taken in Missouri and Arkansas between 

 March 27 (CU 37190, Missouri, Madison Co.) and June 5 (KU 5605, 

 Missouri, Gasconade R.). Males from an Illinois collection (INHS 

 uncat., Rock R., April 25) are at the height of breeding color according 

 to Knapp and show the best development of tubercles. A 51 mm. 

 male from this collection has tubercles present on the belly scales 

 starting halfway from the pelvic to the anal fin origin and extending 

 onto 4 rows of scales per side just anterior to the genital papilla, on 

 2-3 rows above the anal base, and on about 5 midventral rows on 

 the caudal peduncle. There are no tubercles on the fins of these or 

 many other breeding males examined. Winn (1958b, p. 172) re- 

 ported that males of E. caeruleum are larger than females and have 

 larger anal, first dorsal, pectoral, and pelvic fins, but he failed to 

 find breeding tubercles. In spawning, the female of E. caeruleum 

 partially buries herself in the gravel of the stream bottom and the 

 male mounts her (Winn, 1958a; 1958b, fig. 4). Since the beUy and 

 sides of the male are then in contact with the sides of the female, the 

 tubercles may assist him in maintaining his position. 



Temporarily, at least, the other eight tuberculate species of the 

 subgenus Oligocephalus may be placed together in the spectabile 

 group based on the presence of breeding tubercles on the anal fin of 

 males. Etheostoma parvipinne and E. Jricksium have tubercles on 

 the anal fin alone. The other six species, hopkinsi, cragini, punc- 

 tulatum, luteovinctum, pallididorsum, and spectabile, have tubercles 

 in other areas as well. Females of all six species lack tubercles. 



