Gonichthys tenuiculus 



(Garman, 1899) 



Fig. 71 — Gonichthys tenuiculus, male, 52.5 mm. 



Description 



D.IK 10-12); A. 18 (17-20); P. 12-13; AO 6 (5-7) + 11 (9-13), total 17 (15-19); gill rakers 

 (all rudiments included) 5 (4-6) -H 1 + 9 (7-11), total 14 (12-17); vertebrae 39-40 (38-41 ). 



Only G. tenuiculus is illustrated, since all other species of the genus are superficially very 

 similar. 



Body elongate, slender, deepest anteriorly, tapering evenly from origin of dorsal fin to 

 long, slender caudal peduncle. Pectoral fin reaches to over VO^. SAO, over VO^;.., interspace, 

 slightly nearer to VOj. SAO^ about over VOj; SAO;, about over, or a little before, first AOa. 

 SAO:i and Pol about two diameters below lateral line. VLO its diameter behind a vertical from 

 origin of pelvic base and above it by a third, often slightly less, of the distance to lateral line, 

 and usually slightly below, occasionally on, a line from PVO:> to SAO,. Usually 3 or 4 AOp over 

 anal base north of, and 4 or 5 south of, the equator. 



Size: To about 50 mm. 



Least depth of capture: At surface at night. 



Distribution: Found principally in tropical waters but also near the Americas to about 32° 

 N and 22° S (Fig. 72). The lack of collections in the southeastern area, west of the Peru 

 Current, precludes conjecture as to its occurrence there. I did not take the species in 1969 while 

 working on a northeasterly course from Easter Island to about 90° W. 

 Discussion 



Although G. tenuiculus has a wide north-south distribution, I have found no appreciably 

 significant differences in meristic characters between specimens from the extremes of the 

 range. 



Gonichthys barnesi 



Whitley, 1043) 



Description 



D. 12 (11-13); A. 22 (21-23, rarely 20 or 24); P. 16 (14-17, rarely 13 or 18); AO 7 (5-8) + 12 

 (10-14), total 19 (16-21 ); gill rakers (including all rudiments) 5 (4-6) -h 1 -H 8-9 (7-11), total 15 

 (12-18); vertebrae 40-41. 



Gonichthys barnesi is basically similar to G. tenuiculus, differing primarily in having a 

 shorter pectoral fin, reaching to about over VO^ rather than to over VO4, and Pol somewhat 

 farther forward. Also, body proportions listed by Becker (1964a) indicate the anal base of G. 

 barnesi to be somewhat longer than that of G. tenuiculus: (in percent of standard length) 28.1 

 (27.1-29.5) vs 24.3 (23.0-26.1 ). Five to 6, occasionally 7, AOp over anal base. 



84 



