Form C of Diaphus fulgens species complex 



Description 



D. 13-15; A. 12-13; P. 10-11; AO 5 (4-6) + 5 (4-6), total 10 (9-11); gill rakers 6 (5) + 1 + 13 

 (12-14), total 19-20 (18-22); vertebrae 34 (33-35). 



Posterodorsal margin of operculum moderately angulate and recurved. All body photo- 

 phores notably smaller than those of Forms A, B, and D; spaces between those of AO series 

 equal to at least two diameters, often more. PLO slightly behind a vertical from base of upper 

 pectoral ray and above it by 39% (35-46%) of the distance to lateral line. VLO nearly over bases 

 of inner pelvic rays and about midway, 49% (44-53%), between pelvic base and lateral line. 

 SAO3, Pol, and Prcj 1.0 to 1.5 of their diameters below lateral line. VO2.3 interspace 72% 

 (60-86% ) of distance from VLO to VO2, this space notably wider that that of Forms A, B, and D. 

 SAO series somewhat more angulate than in other forms; line through SAO1.2 passes through 

 or slightly before VO-, but far behind SAO3. AOa, 1.5 to 2.0 times its diameter above level of 

 A0a2 and very slightly below a line through VO., and SAO2; last AOa about its diameter above 

 level of the next to last AOa. Pol variably below middle to end of base of adipose fin. 



Luminous scale at PLO large, about equal to space between PLO and pectoral origin, the 

 tissue in somewhat coarse, straight lines that slant posteroventrally at an angle of 30° to 40° to 

 the horizontal. Vn of males, large, undivided, broadly elliptical in shape but more robust 

 anteriorly, filling space between posteroventral margin of orbit, premaxillary and nasal ap- 

 paratus. Vn of females small, ovate, under anterior portion of pupil. 



Teeth of upper and lower jaws similar to those of Forms A and B. Palatine teeth absent 

 except for a small clump at anterior end. In adults, the mesopterygoids are sparsely set bucally 

 with elongate teeth but with a narrow row of thick-set similar teeth mesially, the centers often 

 naked or with a few scattered teeth. In sub-adults, the mesopterygoids tend to be more evenly 

 set with small, conical teeth. 



Size: To about 40 mm. Form C also appears to be a small species; a female of 34.5 mm was 

 fully gravid and one of 28.0 mm had ovaries in an advanced stage of development. 



Least depth of capture: To 85 m at night. 



Distribution: Form C appears to be restricted to a narrow band of equatorial water be- 

 tween about 137° and 165° W, although little or no collecting has been done westerly of this 

 area. It is also known from the Indo-Pacific area (Fig. 1 19). 

 Discussion 



Form C has been taken in greater numbers than any of the other forms. Also, it may be 

 more gregarious, for several tows captured from 20 to 68 specimens each, whereas of the other 

 forms only one to four were taken per tow. 



Form D of Diaphus fulgens species complex 



Description 



D. 13 (12-14); A. 12-13; P. 10-11; AO 5 (4-6) + 4 (3-5), total 9 (8-11); gill rakers 5 + 1 -h 

 10-11 (12), total 16-17 (15-18); vertebrae 33. 



Posterodorsal margin of operculum broadly angulate and slightly recurved. 



Body phosphates moderately large, those of the AO series about one diameter apart. PLO 

 over pectoral origin and nearer it by 35% (29-42%. ) of the distance from them to lateral line. 

 VLO above bases of inner pelvic rays by 39% (36-42%) of the distance from there to lateral line. 



133 



