Fig. 126- 



-Capture localities for Diaphus theta in the northeastern Pacific 

 Ocean. 



Although the name Diaphus theta may properly apply only to specimens from off South- 

 ern California, the name has also been applied to specimens from the eastern Pacific, off Chile 

 (Bussing, 1965). Recently Craddock and Mead (1970) reported the capture of 54 specimens, in 

 19 collections off Chile from an area roughly bounded by 3r-34° S, 72° -92° W (not included in 

 Fig. 126). These authors correctly placed these specimens in a "Diaphus ^/jeta -complex." This 

 southern complex probably extends across the southern Atlantic; I have seen a few specimens 

 from the central Pacific and from off South Africa. 



These southern specimens may represent one or more undescribed species. They differ 

 slightly from those from the type locality of D. theta in having somewhat longer and deeper 

 heads and deeper bodies. They have 11 to 12 pectoral rays rather than the 10 (rarely IDof Z). 

 theta, and the AO photophores more commonly number 5-1-5 (rarely 4 or 6), total 10 (rarely 

 11), rather than the 5 (4-6) -^ 6 (5), total 11 (10-12), of D. theta. Also, there may be differences 

 in size and structure of the luminous scale at PLO; this scale appears to be markedly smaller in 

 the few undamaged southern specimens before me, and the tissue is much more finely convo- 

 luted than in D. theta. I have studied too few specimens from the southern Atlantic Ocean to 

 now attempt a solution to this problem. 



Diaphus brachycephalus 



Tuning, 1928 



Description 



D. 12-13; A. 12-13; P. 11-12 (10); AO 5 (4) -f 4 (5), total 9; gill rakers 6(5-7) -H 1 -I- 13 

 (12-15); total 20-21 (17-23); vertebrae 33 (32-34) (10 specimens). 



Photophores large, closely spaced, those of the AOp series much less than half a diameter 

 apart and often nearly in contact. V0.-„ SAOi, and SAOj form a flatly oblique, nearly horizon- 

 tal, straight line that passes slightly behind SAO3; SAO1.2 interspace about half that of 



141 



