Fig. 32 — Hygophum bruuni . holotype, male, 39.0 mm. From Wisner (1971, p. 41, fig. 2). 



of males and not extending above the peduncular profile. These glands are visible on speci- 

 mens of about 23 mm and appear to be fully formed at about 30 mm; a female (33.5 mm) bore 

 both glands, each weakly but about equally developed. 



Size: To 53 mm. 



Least depth of capture: At surface at night. 



Distribution: Known only from off Chile between about 30°-33° S, 72°-92° W. (Fig. 25). The 

 species is apparently abundant and gregarious. Bussing (1965) reported the capture (as H. 

 hanseni) of 236 specimens in three collections, and Craddock and Mead (1970) reported (as H. 

 hanseni ) a total of 9280 specimens from 45 collections, in surface and deeper hauls. Three of 

 these hauls took 2000, 2500, and 3000 specimens, respectively. 



Discussion 



Hygophum bruuni is closely related to H. hanseni (Taning, 1932) and has previously been 

 so identified. Each has the AOa series notably curved, but in H. bruuni the series is less 

 sharply curved and A0a2 is less elevated than in H. hanseni. Meristic characters (Table 4) are 

 very similar for the two species, except that the numbers of gill rakers average nearly three 

 more total rakers in H. bruuni. Most body proportions are also very similar (Table 5). H. 

 bruuni has a greater depth of body than does H. hanseni, with no overlap in values, and a 

 somewhat greater depth of head, prepelvic, and preanal lengths, and distance from dorsal to 

 anal origins, with but slight overlap. 



Also, in H. bruuni the upper jaw usually extends farther beyond the rear margin of orbit 

 than in H. hanseni, the respective values being 15.85% (10.1-22.4) for 30 specimens of H. 

 bruuni and 10.1% (7.0-11.1) for 8 specimens of //. hanseni from off South Africa. 



Differences were also observed in positions of some photophores; in 90% of a total of 50 

 specimens of H. bruuni, PLO was on a posteriorly oblique line with PVOj and PO2; in the 

 remaining 10% , PLO was distinctly, although slightly, behind this line, a condition found in 

 68.5% of the 8 South African specimens. In H. bruuni VLO was always about midway, or but 

 slightly higher, between lateral line and pelvic base, rather than the higher position common 

 to H. hanseni — three-fourths of this distance nearer the lateral line; this higher position of 

 VLO was shown by Taning (1932, p. 132, fig. 4) and both described and figured by Becker 

 (1965, p. 96, fig. 1 1 ) and figured by Nafpaktitis and Nafpaktitis ( 1969, p. 20, fig. 18). 



38 



