Diaphus theta Eigenmann & Eigenmann, 1890 .

California Headlightfish. To 11.7 cm (4.6 in) SL (Shelekhov 2004). Japan (Nakabo in Nakabo 2002), and southern Bering Sea (Mecklenburg et al. 2002) to Chile (Pequeño 1989). Depth: surface (Childress and Nygaard 1973) to 4,100 m (13,448 ft) (Personal communication: Los Angeles County Museum of Natural History Fish Collection, Los Angeles, California); typically above 800 m (Mecklenburg et al. 2002).