54 



BST 



PTF 



B 



Fig. 25: Profile of (A) lateral 

 view of anterior body of 

 Phoxinus tennesseensis 

 (UT44.5274. 50.0 mm SL. 

 male), and (B) ventral view of 

 breast of P. phoxinus (KU 

 22859. 55.9 mm SL. female), 

 showing the breast scales 

 bearing tubercles. Scale bars 

 = 1 mm. 



bears tubercles at lower density (TS 14[0]) and some regions of the opercle have no 

 tubercles (Chen & Arratia 1996). 



On the ventral side of the body; tubercles are present only on the breast scales at the region 

 anterior to the pectoral fin base and posteroventral to the gill cleft. The breast scales with 

 tubercles are deeply embedded in Phoxinus species, as discussed previously. The tuber- 

 cles are arranged as one row on the scale's apical margin. Except P. cumberlandensis. all 

 other Phoxinus species bear less than 12 tubercles on the apical margin of each breast 

 scale (TS 15[0]): w hereas in P. cumberlandensis, each breast scale might have up to 16 

 tubercles (TS15[1]) (Chen & Arratia 1996). 



In female P. phoxinus, the breast scales bear tubercles at their apical margin (Fig.25B ). 

 However, the tuberculation in the females is different with that in males (Fig.25A. B I 

 (Chen & Arratia 1996). In female P. phoxinus, the breast scales are not deeply embedded, 

 each scale bears about four small tubercles; in male P. phoxinus (and other species of Pho- 

 xinus), many more tubercles might be present on the apical margin of each breast scale. 

 Tubercle type G is present in female P. phoxinus (TS 16[1]) which is not found in other 



