187 



les. Upper lateral stripe beginning dorsally to dorsoposterior margin of opercle, extending 

 almost parallel to lower stripe, and terminating on posterior part of caudal peduncle. A 

 dark mid-dorsal stripe begins at nape and ends at dorsal side of caudal fin base. Dorsal 

 stripe behind insertion of dorsal fin narrower than anterior to dorsal fin origin. Dorsal 

 stripe not evident in specimens less than 25 mm standard length, but lateral stripes occur 

 in these small individuals. 



No melanophores present at chin, except on antero ventral side of lower jaw, which bears 

 dense melanophores. Numerous melanophores present dorsal to upper lateral stripe, and 

 on area between upper and lower lateral stripes. No melanophores present ventral to lo- 

 wer lateral stripe, except in a small area near pectoral fin base, and on ventral edge of 

 caudal peduncle. 



Numerous melanophores present on fins. First four or five pectoral rays bearing more me- 

 lanophores than other rays, especially in breeding males. Melanophores almost evenly pre- 

 sent on pelvic, anal, and caudal fins. On dorsal fin, base bearing more melanophores than 

 other portions of fin. A black spot present at caudal fin base. 



Biology 



Biology of Phoxinus eos has been studied by numerous ichthyologists from the 1930's to 

 the 1980's though it is still not well known. Cooper (1935) and Hubbs & Cooper (1936) 

 studied the reproductive behavior; Tyler (1966) studied lethal temperature; Scott & Cross- 

 man (1973), Stasiak (1978), and Cooper (1983) studied the general biology of the species. 

 The following description is a summary of those publications. 



P. eos occurs in bog ponds, lakes and creeks, but prefers quiet water (Cooper 1983). The 

 fish species found associated with P. eos include P. neogaeus, Pimephales promelas, Um- 

 bra limi, and Culaea inconstans (Stasiak 1978). Hybrids of P. eos x P. neogaeus are com- 

 mon in localities; however, for some reasons, only one parent species was found in these 

 localities (Hubbs & Brown 1929, New 1962, Legendre 1970b, Stasiak 1979, Joswiak, Sta- 

 siak & Moore 1982, Das & Nelson 1989, Goddard & Dawley 1990). 

 Food of P. eos is composed of algae, Zooplankton and aquatic insects (Scott & Crossman 

 1973; Cooper 1983). Cooper (1935) reported that the adult dace was observed eating small- 

 mouth bass fry. 



Maturity of the species is reached in the second summer of life (Cooper 1983). Spawning 

 begins in spring or early summer. Cooper (1935) and Hubbs & Cooper (1935) described 

 that spawning activity occurs from late May to August in Michigan. Females with large 

 eggs were caught in August by McPhail & Lindsey (1970). Hubbs & Cooper (1935) sug- 

 gested some females might spawn at least twice in a single summer season. Cooper (1935) 

 described a complicated reproductive behavior of P. eos. 



Distribution 



Stasiak (1980a) compiled the distribution data, indicating the range from Nova Scotia and 

 Prince Edward Island (Canada), the St. Lawrence basin, and Atlantic drainage of New 

 England, west to Peace-Mackenzie drainage in British Columbia and Northwest Territo- 

 ries, South to upper Missouri River drainage in the Great Plains. 



