5 



INTRODUCTION 



Cyprinidae, the largest freshwater fish family, is divided into two subfamilies (Cavender & 

 Coburn 1992) with 210 genera and 2,010 species (Nelson 1994). Phoxinus, belonging to 

 the subfamily Leuciscinae (Chen 1987b, Howes 1991, Cavender & Coburn 1992, Co- 

 burn & Cavender 1992), is a small sized genus (less than 100 mm in maximum standard 

 length in most species) with nine species, and is the only minnow genus occurring in both 

 North America and Eurasia. Some species of the genus are widely distributed, others are 

 restricted to small drainage areas. For instance, P. phoxinus is widespread in Europe and 

 Asia (Berg 1949, Banarescu 1964), whereas P. tennesseensis is found only from the up- 

 per Tennessee River drainage of Tennessee and Virginia of USA (Starnes & Jenkins 1988). 

 Since the type species of Phoxinus, phoxinus, was described by Linnaeus in 1758 (as Cy- 

 prinus phoxinus), hundreds of papers and books related to the genus have been published. 

 Most of the literature is records of geographical distribution, or brief descriptions of the 

 species of the genus. Only a few of these deal with anatomy and phylogenetic relations- 

 hips of the species in the genus (e.g., Gasowska 1979, Joswiak 1980, Howes 1985). Du- 

 ring the last two centuries, the definition of the genus has been an open question, and its 

 content has changed. For instance, P. neogaeus has been placed in four different genera 

 {Phoxinus, Pfrille, Chrosomus, and Leuciscus) since it was described by Cope (1869) (in 

 Günther 1868). A similar situation is also present in other Phoxinus species. The unstable 

 taxonomic status of the Phoxinus species resulted from lack of a clear definition of the 

 genus, and lack of comprehensive comparisons among Phoxinus species and between Pho- 

 xinus and other related genera. Joswiak (1980) correctly pointed out that this genus "is a 

 focus of controversy involving the relation between Palearctic and Nearctic cyprinids". 

 The situation has not been improved very much since then. 



The present study was designed to review the genus Phoxinus, and to provide a hypo- 

 thesis of its relationships with other genera and among its species. This monograph in- 

 cludes seven sections. A historical review of Phoxinus is presented first, followed by a 

 phylogenetic analysis among Phoxinus and other genera; then I report the results from the 

 comparative morphological study among the species of the genus. Based on the data from 

 these studies, I analyze the phylogenetic relationships among the species of Phoxinus and 

 discuss the biogeography of the genus. Then a classification of the genus is followed by 

 an account of the nine recognized species of the genus. 



ACKNOWLEDGMENTS 



The following individuals and institutions are acknowledged for their loans or donations 

 of specimens to this project: P. Banarescu (Institute of Biology, Bucharesti, Romania), M.- 

 L. Bauchot (Museum National d'Histoire Naturelle, Paris), N.G. Bogutskaya (Zoological 

 Institute, Academy of Sciences, St. Petersburg, Russia), K. Busse (Zoologisches For- 

 schungsinstitut und Museum A. Koenig, Bonn), B.W. Coad (National Museum of Natu- 

 ral Sciences, Ottawa), F.B. Cross, E.O. Wiley and J.T. Collins (University of Kansas, 

 Lawrence, Kansas), W.N. Eschmeyer and D. Catania (California Academy of Sciences, 



