304 Field Museum of Natural History — Zoology, Vol. X. 



Hoplias microlepis Starks, Proc. U. S. Nat. Mus., XXX, 1906, 772 



(Guayaquil); Regan, Biol. Cent. Amer., Pisces, 1907, 167 (Rio 



Chagres; western Ecuador); Eigenmann, Repts. Princeton Univ. 



Exp. Patagonia, III, Pt. IV, 1910, 447. 



Head 2.85 to 3.4; depth 4 to 5; D. 14, rarely 13; A. 10, rarely n; 

 scales in lateral line 42 to 44. 



Body elongate, not much compressed, dorsal region not elevated; 

 head long and low, slightly convex above; interorbital 3.2 to 5 in head; 

 snout 3.45 to 4.6; eye 4.75 to 8.25; mouth large, lower jaw projecting; 

 maxillary reaching beyond posterior margin of eye, mostly slipping under 

 suborbital; teeth present on both jaws, and on palatines, the latter all 

 small; some of the anterior teeth in jaws much enlarged, somewhat 

 flattened, with very sharp cutting edges; gill-rakers poorly developed, 

 5 below angle on anterior arch; lateral line complete, straight, situated 

 on median line of side; scales moderate, regularly placed, cycloid, 15 to 

 18 on median line in advance of dorsal ; 1 1 , rarely 10, rows of scales across 

 caudal peduncle from one lateral line to the other; 5 complete rows 

 between the lateral line and anal fin; dorsal fin inserted midway between 

 tip of upper jaw and base of caudal, or slightly nearer the former; adipose 

 wanting; caudal fin convex; anal fin inserted posteriorly, the longest 

 ray reaching nearly to base of lower caudal ray; ventral fins inserted 

 under base of pectorals, slightly nearer base of caudal than tip of lower 

 jaw; pectoral fins inserted sUghtly behind margin of preopercle, failing 

 to reach base of ventrals by 4 or 5 rows of scales. 



Color of large specimens very dark brown above, Hghter below, 

 uniform, without band or blotches; young much paler, mottled with 

 brown and \\ath a more or less distinct dark lateral band. The dark 

 mottlings of the young later appear to become concentrated into dark 

 blotches along the side. The dark lateral band is much more persistant 

 in some specimens than in others. Fins all with dark spots forming 

 more or less distinct wavy bars. 



There are 175 specimens, ranging from 27 to 460 mm. in length, in 

 the present collection. It was found in all streams visited on both 

 slopes of Panama, except in the Rio Tuyra Basin where it is replaced 

 by H. malabaricus. A very abundant fish in lowland streams, usually 

 preferring shallow water where there is an abundance of vegetation. 

 It is called, "Perro Pesca"= dog fish, by the natives because of its 

 large sharp teeth and its habit of snapping at objects coming near it. 

 Care must be exercised in picking specimens from the net, as it is able 

 to inflict painful wounds with its sharp teeth and powerful jaws. This 

 fish, although used to some extent as food, is not regarded as of good 

 flavor and is of minor importance. 



