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bound above and below by unpigmented stripes. Slight variation in coloration -'■'■ ■ 

 pattern is evident in specimens collected from different areas, with the darkest 

 coloration present in individuals from clear or blackwater rivers. Overall coloration 

 dark brown or black, with unpigmented areas appearing white or yellowish in 

 preserved specimens. Top of head nearly uniform brown except for a short, 

 immaculate or weakly pigmented band along the posterolateral margin of each 

 frontal just in front of the supraoccipital. Opercular area uniformly brown. Lips 

 and upper surface of barbels fringed with brown. Chin, throat, and belly often 

 without much pigment, but occasionally with scattered flecks of brown. Top of back 

 from dorsal fin origin to caudal fin with a uniform chocolate brown stripe, extending 

 laterally to about the upper fourth or third of the side. A prominent, sharply 

 delineated stripe extending length of the body over lateral line, bordered above and 

 below by unpigmented white or cream colored stripes; lower unpigmented stripe of 

 nearly equal width as brown stripe, the upper unpigmented stripe slightly narrower 

 than both. Pigment on lower half of sides of body variable, but typically consisting 

 of diffuse, brown specks that extend onto the base of the anal fin. 



Dorsal fin with brown streaks along anterior border of spine and over distal 

 portions of branched rays. Adipose fin with scattered brown flecks throughout, 

 concentrated near base. Distal margin of caudal fin unpigmented, but the rest of 

 the fin with dense brown pigment, occasionally appearing slightly striped along the 

 principal rays, but never with distinct round or elliptical spots as in other fork-tailed 

 species. Pectoral and pelvic fins invariably with brown streaks on upper surface, 

 usually concentrated near base and along outermost rays. Anal fin with diffuse 

 brown specks throughout, often darker and more concentrated near base and along 

 distal margin. 



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