139 



Four radials are present at the posterior margin of the basipterygium. The radials articu- 

 late with the basipterygium anteriorly, and the anterior end of the pelvic rays posteriorly. 

 Radials 1 to 3 (from distal to proximal) are small, cubic, or spherical in shape. Signifi- 

 cant variation is absent in these bones in Phoxinus. Radial 4 is the largest among the four 

 radials. Radial 4 is an elongated triangle in P. cumberlandensis, erythro gast er, eos, pho- 

 xinus, neogaeus, oreas, and in the outgroups (TS 205 [0]); it is an elongated bar in other 

 species of Phoxinus (TS 205 [1]). 



Seven to eight rays of the pelvic fin are generally present in Phoxinus. See below for dis- 

 cussion on variation of the number of fin-rays for each species of Phoxinus. 



Dorsal Fin 



Eight pterygiophores are present in all Phoxinus species. In cyprinids, each pterygiophore 

 is composed of three portions: proximal, middle, and distal parts (Harder 1975, Chen 

 1987a). The proximal part (Fig.90A-G) is elongated and is the main element of pterygio- 

 phore. The middle part is short bar-shaped; its dorsal and ventral sides are concave to ar- 

 ticulate with the distal and proximal parts of the pterygiophore respectively. The distal 

 part is a small spherical bone. The middle and distal parts in all pterygiophores are simi- 

 lar to one another in shape and without variation among the species of Phoxinus. The pro- 

 ximal parts of the second to the eighth pterygiophores are not forked and similar to one 

 another in shape, but decrease in size posteriorly. The proximal part of the first pterygio- 

 phore, the largest one, is forked at its ventral portion, and expanded at its middle porti- 

 on. The proximal part of the first pterygiophore in P. tennesseensis is slender (TS 206[1]) 

 than that in other species of Phoxinus or in the outgroups (TS 206[0]). In P. brachyurus, 

 the fork on the proximal part of the first pterygiophores is deep, the anterior process of 

 the fork is almost equal to the posterior process in length (TS 207[1]). In other species 



/ 



A 



B 



C 



Fig.91: Lateral view of the 

 proximal part of the first 

 pterygiophore of anal fin of 

 Phoxinus. A: P. eos (KU 

 12255, 43.0 mm SL); B: P. 

 tennesseensis (UT 44.5274, 

 50.0 mm SL); C: P. oreas 

 (KU 3259, 52.2 mm SL). 

 Scale bars = 1 mm. 



