150 



distribution of Phoxinus in North America exemplifies this. The North American portion 

 of the ancestor of Phoxinus became the ancestor of the erythrogaster clade after its iso- 

 lation from Asia in the Tertiary. The erythrogaster species pair (P. eos and P. erythro- 

 gaster) speciated from their ancestor probably by the adaptation to different habitats, or 

 b\ some vicariant event. P. eos prefers a boggy environment, whereas P. erythrogaster 

 lives in headwater or spring habitats. P. eos has a northern distribution not overlapping 

 the range occupied by P. erythrogaster, but partially covering the geographic distribution 

 of P. neogaeus. P. erythrogaster is distributed from Maine and Western Pennsylvania to 

 Arkansas and Alabama, and a few isolated populations are present in Tennessee, Kansas, 

 Colorado, and New Mexico (Köster 1957: Cross 1970). (See the species account of P. 

 erythrogaster below). 



These isolated populations of P. erythrogaster indicate this species once had an extensive 

 southwestern distribution (Cross 1970). Because P. erythrogaster usually occurs in head- 

 water or spring habitats. Cross (1970) interpreted the current distribution of this species 

 caused by "(1) southward dispersal (of the species) during glacial advances, due to at- 

 mospheric cooling and consequent cooling of streams, probably supplemented by increa- 

 sed moisture and more consistent flow; (2) subsequent extirpation of most southern 

 populations as atmospheric temperatures became warmer, heating the shallower streams 

 and causing many of them to dry. but leaving remnant populations of these species near 

 springs." (Cross 1971:251). The isolated populations of P. eos and P. neogaeus might be 

 interpreted in a similar manner (Cross 1971). 



The ancestor of the oreas species complex was hypothesized to have been distributed in 

 the eastern portion of the preglacial Teays River drainage (Starnes & Jenkins 1988). This 

 speciation event might be caused by the "capture of an upper Teays (New River) tributary 

 by an upper Tennessee River (Holston River) tributary 1 ' (Starnes & Jenkins 1988:527). 



TAXONOMY OF PHOXINUS RAFINESQUE. 1820a 



Synonymy 



Phoxinus Rafinesque, 1820a: 236 (type species: Cyprians phoxinus Linnaeus. 1758: 322; 

 Europe). 



Chrosomus Rafinesque. 1820a: 237 (type species: Luxilus erythrogaster Rafinesque. 

 1820a: 237: Kentucky, USA). 



Phoxinus Agassiz, 1835: 37 (type species: Cyprians phoxinus Linnaeus, 1758: 322; Eu- 

 rope). 



Eulinneella Dybowski, 1916: 101 (type species: Cyprinus phoxinus Linnaeus, 1758: 322; 

 Europe). 



Pfrille Jordan, 1924: 71 (Type species: Phoxinus neogaeus Cope, 1869: 375. in Günther 

 1868; New Hudson. Livingston County. Michigan, USA). 



? Acahara Jordan & Hubbs, 1925: 177 (type species: Richardsonius semotilus Jordan & 

 Starks, 1905; Japan). 



