BREEDING TUBERCLES IN FISHES — COLLETTE 595 



rocks in a spawning position similar to that described by Winn (1958b, 

 fig. 4) for E. caeruleum (Mount, 1959). 



Subgenus Oligocephalus Girard 



Twenty-one species are presently placed in this, the largest subgenus 

 of Etheostoma. There appear to be three different tuberculate species 

 groups and one nontuberculate group. Males of the nianguae group, 

 nianguae Gilbert and Meek and sagitta (Jordan and Swain), have 

 conical tubercles on the ventral scales. Males of the radiosum group, 

 radiosum (Hubbs and Black), whipplii (Girard), and caeruleum (Storer) 

 have tubercles that are similar to but not as high as those in the E. 

 nianguae group. Eight other tuberculate species may best be placed 

 together for the present, although thej differ from one another in the 

 details of tubercle distribution: punctulatum (Agassiz), Jricksium 

 Hildebrand, hopkinsi (Fowler), parvipinne GHhert and Swain, spectabile 

 (Agassiz), luteovinctum Gilbert and Swain, pallididorsum Distler and 

 Metcalf, and cragini Gilbert. The species in the spectabile group 



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Figure 6. — Male of Etheostoma {Oligocephalus) nianguae showing the distribution of 

 breeding tubercles (CU 32888, Missouri, Osage River, March 16, 89 mm. SL). 



differ from the two previous groups in having tubercles on the anal fin. 

 Two of the species in this group have tubercles on only the anal fin, 

 while the others also have them in additional regions. This leaves a 

 residue of eight species which appear to be nontuberculate: asprigene 

 (Forbes), swaini (Jordan), mariae (Fowler), juliae Meek, pottsii 

 (Girard), lepidum (Baird and Girard), exile (Girard), and grahami 

 (Girard). 



A fine breeding male of E. nianguae (CU 32888, Missouri, Miller Co., 

 Big Tavern Cr., Mar. 16, 1957, a specimen overlooked by Kuehne and 

 Bailey, 1961) has breeding tubercles well developed on about 12 mid- 

 ventral scale rows just anterior to the genital papilla (fig. 6). There 

 are no tubercles on either the pelvic or anal fins. There is, however, a 



