17 



Bullough (1939. 1940) studied the reproductive cycle of P. phoxinus. An internal repro- 

 ductive rhythm able to work without the external seasonal change was reported (Bullough 

 1939). 



1940-1949 



During these years, a few studies on the biology of species of Phoxinus were conducted. 

 Frost (1943) studied the natural history of P. phoxinus. such as habits, age. growth, food, 

 and reproduction. Frost 1 1946) also demonstrated dietary relationships among P. phoxinus 

 and its associated fish species. The lateral line of P. phoxinus was studied by Lekander 

 (1949). 



Berg (1949) 1 1964. English translation) reviewed the Eurasian Phoxinus species and pro- 

 posed a synonym list of the genus. This synonymy, in fact, is a modification of that in 

 Berg (1932). The difference between these two synonymies is that Gila Baird & Girard 

 of North America was added to the synonymy of Berg 1 1932) in Berg ( 1949). as a sub- 

 genus of Phoxinus. A key was provided for the eight Eurasian species in Berg (1949). 

 However. Gila was removed from Phoxinus. and considered as a valid genus name b\ 

 Uyeno (1960). 



1950-1959 



Bailey (1951) first lumped Pfrille into Chrosomus though this lumping was challenged by 

 a few ichthyologists (e.g.. Gasowska 1979). Inderhill ( 195" 7 ) studied the relationships bet- 

 ween the distribution of minnows and darters and Pleistocene glaciation in Minnesota. 

 USA. Three species of Phoxinus including P. neogaeus, eos. and erythrogaster were found 

 in Minnesota. These species, based on Underhill (1957). had three different origins in Min- 

 nesota. P. eos. which was common in the state, might have arrived at the earliest time. 

 P. enrhrogaster was considered as a late migrant from the lower Mississippi basin, and 

 ecologically restricted in the region. P. neogaeus. common in Lake Superior and the Hud- 

 son Bay drainage system but absent or represented by relicts in other basins, did not enter 

 from the Lower Mississippi basin (Underhill 1957). 



1960-1969 



Bailey & Allum (1962) suggested that populations of two species of Phoxinus neogaeus 

 and P. eos in South Dakota are glacial relicts. These authors also found that hybrids of P. 

 neogaeus x P. eos were common. 



Banarescu (1964) reviewed the synonyms of Phoxinus. Though I can not agree w ith some 

 of his synonyms. Banarescu ( 1964) is one of the most important works in the systema- 

 tics of Phoxinus. At least two contributions to the taxonomic study of the genus were 

 made by Banarescu ( 1964). He is the first one to consider the North American Chrosomus 

 Rafmesque a synonym of Phoxinus: he also confirms Pfrille Jordan a synonym of Pho- 

 xinus. The differences between the synonymies of Banarescu ( 1964) and Berg ( 1949) are 

 tw o: (1) Banarescu considered Chrosomus Rafmesque as a synonym of Phoxinus: and (2) 

 Banarescu deleted Gila, Eulinneella, Lagowskiella. Eupallasella. and Czekanowskiella 

 from the synonym list of Berg (1949). Banarescu's synonymy, especially his opinion on 



