319 



Ageneiosus dawalla: Eigenmann and Eigenmann 1888:150 (citation; y4. inermis 



Valenciennes and^. sebce placed in synonymy); 1891:35 (after 1888 account). 

 V Eigenmann 1909:322 (listed in table). Steindachner 1910:401-402, pi. 10 



(nomenclature; description). Gosline 1945:25 (citation; ^4. inermis [not 

 ; Linnaeus] Cuvier and Valenciennes and^.5efeaeGunther placed in 



synonymy). Miranda-Ribeiro 1911:404-405 (description; comparison withy4. 

 valenciennesi). Miranda-Ribeiro 1962:3 (museum records). Burgess 

 1989:286 (citation). .. ., 



Ageneiosus therezinae Steindachner 1909:341-342 (original description [type locality: 

 Rio Puti {Poti}, and Rio Pamahyba { =Pamafba}, Therezina { =Teresina}, 

 Brazil]. Gosline 1945:25 (citation). Fowler 1951:454 (partial synonymy; 

 ■ distribution). Burgess 1989:286 (misspelled as //lerez/ne). -,, 



Ageneiosus ogilviei Fowler 1914:266 (original description [type locality: Rupununi 

 River, Guyana]; comparison with ^. brevifilis). Gosline 1945:25 (citation). 

 Burgess 1989:286 (citation). 



Pseudogeniosus brevifilis: Delsman 1941:70 (Rio Amazonas, Santa JuUa). 



Pseudoageneiosus brevifilis: Devincenzi and Teague 1942:56-57, fig. 4 (description; 

 coloration; photograph; ecology; Rio Uruguay). 



Ageneiosus sp.: Novoa and Ramos 1978:105, fig. 39 (ecology; fisheries). 



Diagnosis * ., - ; ; ^ " 



^ " Ageneiosus brevifilis is distinguished from all other species of the genus except 

 A. marmoratus by a combination of the robust body form; an obliquely truncate 

 caudal fm with 8+10 principal rays; a high number of pectoral fin rays (13-16); a 

 very reduced, encapsulated swimbladder; and the first pectoral element not forming 

 a stiffened, serrated spine. The species reaches a much greater length (to at least 45 

 cm) and lacks the distinctive mottling pattern characteristic of ^4. marmoratus. 

 Further distinguished from large congeners by the high numbers of branchiostegals 

 (modally 11), pleural ribs (10-12), preanal vertebrae (20-23), total vertebrae (55-58), 

 and numerous (X = 25) gill rakers that are short, conical, and lack the crenulated 



