Fig. 31 — Hygophum reinhardtii . male, 47.2 mm. From Becker (1965, p. 91. fig. 9). 



Body generally more slender than in H. atratum, body depth about 4.0 to 4.5 times in SL. 

 Four (3-5) AOp over anal base. Upper Pol noticeably before a vertical from adipose base. A 

 narrow, pale, whitish crescent present on posterior margin of iris. 



Supracaudal luminous glands of males undivided (Fig. 31), filling about half the supra- 

 caudal space; infracaudal glands of females of 3 or 4 coalesced or seldom separated spots (Fig. 

 30). The glands of males begin to appear before 25 mm, but those of females are not apparent 

 until about 30 mm. 



Size: To about 55 mm. 



Least depth of capture: At surface at night. 



Distribution: H. reinhardtii occupies the warmer waters of the eastern Pacific Ocean 

 between about 30° N and 30° S, except for a hiatus of about 20° of latitude north of the eastern 

 equatorial region (Fig. 25). In view of the collecting effort in that region and the finding of 

 other species of the genus, it seems likely that this species is indeed absent or very uncommon 

 there. 



The lack of collections in the south-central Pacific precludes discussion of its occurrence 

 there, but Becker (1965 ) reported it from the southwestern sector (northeast of New Zealand 

 andTasman Sea). H. reinhardtii is not known from the Indian Ocean. Becker (1965) ques- 

 tioned its reported occurrence in the South Atlantic. 

 Discussion 



The apparent geographical separation of the two groups of//, reinhardtii in the eastern 

 Pacific Ocean is supported by the occurrence of one more ray in the anal fin of the southern 

 group than in that of the northern; the respective averages and ranges of counts are: 22.63 

 (21-25) vs 21.37 (20-23). All other meristic and morphometric characters for each group are 

 very similar. 



Hygophum bruuni 



Wisner, 1971 



Description 



D. 11 (10-12); A. 21 (20-22); P. 15 (14-16); AO 5 (4-6) + 7 (6-8), total 12 (11-13); gill rakers 5 

 (4-6) -^ 1 -f- 15(14-16), total 20 (19-21); vertebrae 36 (35). 



PLO about midway between lateral line and origin of pectoral fin; VLO slightly above 

 midway between lateral line and pelvic origin and about over the latter. SAO series in a wide 

 angle varying from 130° to 160°. AOa series evenly and moderately curved, with A0a2 seldom 

 higher than AOa.,. Greatest body depth about 25% of SL. 



Supracaudal luminous glands of males undivided, small but prominent, standing well 

 above profile of caudal peduncle; infracaudal glands of females undivided, smaller than those 



37 



