178 



rays. Anal fin originated slightly behind insertion of dorsal fin; with two procurrent rays, 

 and eight rays. Caudal fin deeply forked, lobes sharp, with 4-8 dorsal procurrent rays, four 

 or five ventral procurrent rays, and 19 (10+9) principal rays. 



Scales well embedded, covering entire body. Scales at ventral part of body deeply em- 

 bedded. 



Left and right supratemporal canals widely separated from each other; five pores. Otic ca- 

 nal with eight pores. Supraorbital canal with 10 pores. Infraorbital canal with 15 pores. 

 Preopercular canal with eight pores. Mandibular canal with three pores. Body lateral line 

 pored scales 34, last pored scale located at the position of the posterior margin of the pec- 

 toral fin; no pored scales found in individuals smaller than 33 mm standard length. 

 Pharyngeal bone broad, its posterior limb straight; pitted surface broad with four to six 

 major fossae. Pharyngeal teeth in one row, 5-5. Teeth elongate, slender, and hooked at tip 

 (not or very slightly hooked in one or two teeth near the posterior limb). 

 Vertebrae 38 or 39; precaudal vertebrae 20, caudal vertebrae 18 or 19. 

 Intestine long, about six complex loops. Its length 215% of standard length. 

 Anterior chamber of gas bladder shorter than the elliptical posterior one. Former about 

 60% of the latter in length. Constriction of the gas bladder developed and elongated. Pneu- 

 matic duct connected with anterior portion of the posterior chamber. Peritoneum dark. 

 Tuberculation. Tubercles present on entire body and head, including their lateral, dor- 

 sal, and ventral sides. Dorsal part of snout more densely tuberculated than rest of head. 

 Ventral side of head bearing fewer tubercles than rest of head. Each scale in five or six 

 rows on the breast bearing four or five tubercles on its apical margin. Each scale on an- 

 terolateral side of body bearing one tubercle near the apical margin. Scales on posterola- 

 teral part of body, especially ventral part of the caudal peduncle, bearing four to six 

 tubercles at apical margin; tubercles in this region more developed than that in other parts 

 of body. Tuberculation on all fins similar to that in Phoxinus cumberlandensis. 

 Coloration. Two lateral stripes present at the sides of body. Lower stripe extending from 

 anterior portion of snout to caudal fin base. In large individuals, lower stripe interrupted 

 at a point dorsal to anal fin origin. In small individuals (less than 30 mm in standard 

 length), the stripe is complete. A dark dorsal stripe extending from nape to caudal fin base 

 without inteiTuption; dorsal stripe more distinct in small individuals than in larger ones. 

 Numerous melanophores present on sides of body. Region dorsal to the upper lateral stripe 

 darker than region ventral to stripe. Ventral part of body lacking melanophores, except at 

 anal fin base, ventral caudal peduncle and pectoral fin base where few melanophores 

 present. Dorsum and dorsolateral portion of head bearing numerous melanophores. 

 Numerous spots present on area dorsal to the upper lateral stripe in some large indivi- 

 duals, especially in breeding males. Melanophores present on ventral aspect of head. 

 Ventral side of head darker in breeding male than that in breeding female. 



Biology 



P. tennesseensis occurs in small rivers with fast current and low water temperature (sel- 

 dom exceeding 20°C), as well as in sluggish ponds with fine gravel, sand and silt sub- 



