NO. 3538 CHARACID FISHES — ^WEITZMAN 47 



Poecilohrycon eques (Steindachner) 



Figure 12 



Nannostomus eques Steindachner, 1876, p. 126, pi. 9, fig. 3 (original description; 

 type locality: Peruvian Amazon above Tabatinga; types in Vienna Mu- 

 seum). — Eigenmann and Eigenmann, 1891, p. 49 (listed). — Sterba and 

 Tucker, 1962, p. 215 (description and aquarium notes). 



Poecilohrycon auralus Eigenmann, 1909, p. 43 (original description; type locality: 

 British Guiana, canal at Christianburg; holotype in Chicago Natural History 

 Museum); 1910, p. 427 (listed). — Innes, 1935, p. 156 (description from life 

 and photograph). 



Poecilohrycon trifasciatus. — (not Steindachner) Eigenmann, 1912, p. 284, pi. 37, 

 fig. 2 (description). 



Poecilohrycon eques. — Eigenmann, 1910, p. 427 (listed). — Eigenmann and Allen, 

 1942, p. 288 (listed). 



Nannobrycon eques. — (in part) Hoedeman, 1950, p. 23 (description; photograph); 

 1954b, p. 82 (description; photograph); 1954b, p. 82 (description; photo- 

 graph) . 



Diagnosis. — The unique feature of this species is its five lateral 

 horizontal stripes. In addition it may be distinguished from all 

 other nannostominans by the following combination of characters: 

 No perforated lateral-line scales; 24 to 25 scales in lateral series; 

 33 to 34 vertebrae; iii, 9 anal fin rays; 16+24 gill rakers; 12 teeth in the 

 second tooth row of dentary. 



Description". — Body elongate, somewhat cyhndi'ical through an- 

 terior half, but sides flattened and compressed posteiiorly. Greatest 

 depth occurs between posterior tip of appressed pectorals and anterior 

 base of dorsal fin. SL of largest specimen 35.0 mm. (largest aquarium 

 specimen examined, a female, with SL of 37.0 mm.). Greatest body 

 depth 4.5 (4.0-5.1); least depth of caudal peduncle 10.0 (10.0-11.0); 

 length of caudal peduncle (including both sexes) 6.7 (6.0-7.1); snout 

 tip to origin of dorsal fin 1.7 (1.7-1.8); snout tip to origin of anal 

 fin about 1.3 in all specimens examined. 



Head elongate, rather acute in vertical profile with tip of snout 

 obtuse. Snout region somewhat depressed. Top of head very 

 shghtly convex between eyes. Head 3.5 (3.5-3.7); eye in head 3.3 

 (3.0-3.5); snout in eye 0.9 (0.8-1.0); least width of bony interorbital 

 in greatest eye diameter 1.0 (0.9-1.0). 



Premaxillary with 8 to 9 teeth, each quadri- to quinquecuspid, 

 cusp next to posterolateral one largest. Maxillary with 1 quadri- or 

 quinquescuspid tooth, cusps subequal. Dentary with 7 to 9 quinque- 

 to sexcuspid teeth. Posterior 1 or 2 teeth usually with 3 cusps. 

 Either central cusp or 2 posterolateral cusps largest (fig. 12). About 

 12 teeth in second dentary tooth row. Gill rakers 16+24. 



Dorsal fin rays ii,8; anal iii, 9; pectoral i,9 to i,ll; pelvics ii,7. 

 Adipose fin present or absent, seemingly not correlated with geo- 



