252 



Body width greatest at pectoral-fin origin (18-24% SL), gradually attenuated 

 to caudal peduncle. Body depth at dorsal-fin origin 16-24% SL. Dorsal profile of 

 body slightly convex, the belly gently rounded. Least caudal peduncle depth 8-11% 

 SL. '■" "■ '.^ -:r-i-^'/':- 



Dorsal fin in females and non-nuptial males relatively short (14-20% SL), 

 constricted at base, and with a moderately short spine that is weakly serrated along 

 the distal half or more of the posterior margin. Dorsal spine of nuptial males 

 greatly elongated (23-35% SL), armed along anterior border with about 30-40 sharp, 

 antrorse odontodes (Fig. 23d), smooth on posterior margin. Adipose fin relatively 

 large for the genus, posterior margin free, forming short flap. Caudal fin large and 

 moderately forked, with 8 + 9 principal rays, and about 19-23 (x = 21) upper and 

 14-19 (X = 16) lower procurrent rays; tail often frayed and appearing truncate or 

 rounded, as a result of damage inflicted by fin-eating characiforms. Anal fin 

 relatively short, obliquely angled upward toward caudal peduncle, with 32-39 (X = 

 36) fin rays. Anal pterygiophores 29-36, modally 33. Anterior 3-7 anal lepidotrichia 

 enlarged and coalesced to form gonopodium in nuptial males. Pectoral fin 

 triangular, not reaching to pelvic origin. Pectoral spine relatively short and thin, 

 with about 10-22 sharp, retrorse serrae on posterior margin in specimens greater 

 than 100 mm SL; serrae reduced to short, rounded bumps near base (small 

 specimens have fewer serrae, about 6-10, that are proportionally larger relative to 

 the length and diameter of the shaft). Soft pectoral rays 11-13, modally 12. 



Total vertebrae 45-48, modally 47. Preanal vertebrae 17-20, modally 18. 

 Pleural ribs 8-10, modally 9. Swimbladder in adults a relatively small bipartite 

 capsule, encased by superficial ossification of the complex centra, with two short, 

 turgid, posterior caecae (Fig. 21a). 



