NO. 3538 CHARACID FISHES — WEITZMAN 9 



Scales 24 to 25 in lateral series. No perforated lateral line scales. Adipose 

 fin present or absent. Gill rakers 16 + 24. Teeth in inner dentary row 12; 

 teeth in outer dentary row 9 Poecilobrycon eques (p. 47) 



Genus Nannostomus Gunther 



Nannostomus GUnther, 1872, p. 14G (type species : Nannostomus beckfordi Gunther, 

 1872, by monotypy). 



Diagnosis.— Among the Lebiasininae the following character ap- 

 pears unique for this genus: Second infraorbital bone without bony 

 canal for infraorbital branch of laterosensory canal; in addition, snout 

 short, 1.0 to 1.4 in eye diameter. Correlated with the short snout, 

 Nannostomus has a shorter, broader ethmoid and vomer, a shorter 

 antorbital and infraorbital, and a shorter mesopterygoid and nasal 

 bone than Poecilobrycon. An adipose fin may be either present or 

 absent. Either the prmiary or tertiary, or both primary and tertiary 

 horizontal stripes may be present or absent. The anal fin rays of the 

 males may be greatly modified or scarcely modified as an accessory 

 organ. The body is short to fairly elongate, the depth being 3.5 to 5.0 

 in the standard length. 



The name Nannostomus is derived from the Greek vavocr, meaning 

 httle or dwarf, and aTo^a, meaning mouth. 



Nannostomus espei (Meinken) 



Figure 1 



Poecilobrycon espei Meinken, 1956, p. 31 (original description; no type locality; 



types in collection of Meinken and at Stanford University, lectotype SU 



51593). 

 Nannostomus espei — Bohike, 1956, p. 2 (description; unnamed creek emptying 



into the Paruma River, a tributary of the Kamarang River, which empties 



into the Mazaruni River, British Guiana). — Sterba and Tucker, 1962, p. 213 



(description and aquarium notes) . 



Diagnosis.— Secondary and tertiary horizontal stripes absent; pri- 

 mary horizontal stripe poorly developed; permanent blotches on sides 

 of living specimens (blotches do not disappear during daytime); 

 scales (fig. 1) very much in outhne hke scales of members of subtribe 

 Pyrrhulinina (see description on page 12). Nannostomus espei differs 

 from all members of subtribe Nannostomina except Nannostomus 

 marginatus by having fewer than 23 scales in lateral series. 



Description. — Body elongate, sides flattened, and body compressed 

 posteriorly. Greatest depth between posterior tip of appressed pec- 

 torals and anterior part of base of dorsal fin. Standard length of 

 largest specimen examined, 28.1 mm. Greatest body depth 4.3 in all 

 specimens; least depth of caudal peduncle 9.6 (9.4 to 10.0); length of 

 caudal peduncle of both sexes 6.4 (6.1 to 7.0); snout tip to origin of 

 dorsal 1.9 (1.9 to 2.0); snout tip to origin of anal 1.3 in all specimens. 



