61 



Similar to the outgroups, all Phoxinus species have a dark dorsal stripe at the dorsum of 

 the body from the nape to in front of the caudal fin. No significant variation of the stripe 

 is present in Phoxinus. 



The first to sixth pectoral fin-rays and the interradial membrane between the rays bear 

 melanophores. The first ray has more melanophores than the remaining (Fig.30A, B). Rays 

 and membrane behind the sixth ray bear few melanophores. Therefore, the first few rays 

 and the membrane are darker than the rest, as in many cyprinids. In most Phoxinus spe- 

 cies, breeding individuals show slightly darker pectoral fin than nonbreeding ones (TS 

 26[0]). However, in P. neogaeus, the pectoral fin is much darker (TS 26[1]) in breeding 

 males than in nonbreeding males (Fig.30A, B). No variation of the color pattern is pre- 

 sent in nonnuptial individuals among the species of Phoxinus. 



All rays of the pelvic fin and interradial membranes between rays bear melanophores. The 

 first ray is darker than rest of the fin. No significant variation in color pattern of the pel- 

 vic fin is present in the genus. 



Melanophores are present on the dorsal fin (Fig.30C, D), and higher density of the mela- 

 nophores is present on the first ray than on other rays. The highest density of melano- 

 phores is at the fin's base. In P. cumberlandensis and tennesseensis, the melanophores are 

 not much more concentrated at the base than rest of the dorsal fin (TS 27[0]; Fig.30D). 

 In other species of the genus, the melanophores are much more concentrated at the base 

 than rest of the dorsal fin, thus a very dark region is present at the base of the dorsal fin 

 (TS 27[1]; Fig.30C). The latter condition is not present in the outgroups. 

 All anal fin rays and the interradial membrane bear malanophores. The first fin ray (un- 

 branched) has slightly more melanophores than the remaining rays. No dark patch is for- 

 med at base of the anal fin. No significant variation in anal fin pigmentation is present 

 among the species of Phoxinus. 



The caudal fin, like the dorsal one, bears melanophores on entire fin. More melanopho- 

 res are present at the dorsal and ventral part of the caudal fin than the middle of the fin 

 in most species of Phoxinus. A round blotch is present at the base of the fin (TS 28 [0]) 

 in P. phoxinus, tennesseensis, erythro gast er, eos, and neogaeus; the blotch is absent in 

 other species of Phoxinus (TS 28[ 1 ]). In the outgroups, the caudal fin bears a round black 

 blotch at its base. 



Intestine and Gas Bladder 



Intestine (Figs 31A-G, 32A-D) 



The intestine of cyprinids is relatively simple without a stomach and pyloric appendages 

 (caeca) (Harder 1975). However, in some species of cyprinids the most anterior section 

 of the intestine is enlarged, forming a pseudogaster. The length and coiling patterns of the 

 intestine show a lot of variation in cyprinids. Kafuku (1958) studied the intestines of 

 cyprinids and defined six looping types in the family, i.e., (in order of increasing com- 

 plexity) S-, Zacco-, Gobionidae-, Cyprinus-, Ctenopharyngodon-, and Acheilognathinae- 

 types. Harder (1975) added another, the Screw-type, to the list. The morphology of the 

 intestine is widely used in the identification of species and genera in Cyprinidae (e.g.. 

 Cross 1967, Cross & Collins 1975). 



