■ ■..-;--/■■■ -•,■' ■ .. ■ / :"■ .- '.■■'.■'; 307 



. * Ageneiosus pofystictus (Stemdachner) ' 



■^^ •, O. Fig. 13, 21, 53-54 



V . . -^ Table23 



• ^ ' ' - ;,■■.-» .,<':■■,' I u ., 



Ageneisus pofysHctus Steindachner 1915:217-218 (original description [type locality: 

 mouth of Rio Negro, Brazil]). • , < • : 



Ageneiosus pofysHctus: Steindachner 1917:84-86, pi. 7, figs. 1-3 (expanded description 



of 1915 account; generic name corrected). Gosline 1945:24 (citation). 

 ; . Fowler 1951:453 (partial synonymy; distribution). Britski 1972:99,109 

 (citation). Ferraris 1988:126 (citation). Burgess 1989:286, 629 (citation; 

 photograph of hve specimen [pi. 147], misidentified as Ageneiosus sp. cf. 

 guianensis). 



Diagnosis '" "^ - 



Ageneiosus pofystictus is the only member of the genus having a weakly forked 

 to strongly emarginate tail with broadly rounded lobes in adult individuals. Further 

 distinguished from all congeners by its unique coloration, consisting of dark black 

 spots and reticulations over most of the head and body. In its general body shape ^4. 

 pofystictus most closely resembles ^4. brevifilis, but is distinguished from that species 

 by its shghtly forked tail, versus an obUquely truncate one in brevifilis, and by the 

 lower numbers of pectoral-fin rays (averaging 13.6, versus 14.6 in brevifilis), ribs (9- 

 10 versus 10-12), preanal vertebrae (19-20 versus 20-23), and total vertebrae (51-53 

 versus 55-58). ' :■ 



Description X 



A moderately large species, commonly exceeding 350 mm SL and reaching 

 up to 450 mm SL. Head fairly blunt (26-31% SL in length, 18-22 % SL in width), 

 body moderately elongate. Dorsal profile of head smoothly sloping in a straight hne 

 to dorsal-fin origin. Contour on top of body nearly straight or very slightly convex 



