Idiacanthus antrostomus Gilbert, 1890 .

Pacific Blackdragon. Males to 7.6 cm (3 in) TL (Fitch and Lavenberg 1968) (Fujii in Masuda et al. 1984), females to 61 cm (24 in) SL (Kamikawa 2017). Western Pacific Ocean north to Hokkaido, Japan (Aizawa in Nakabo 2002); Triangle Island (50°48’N, 129°06’W), British Columbia (Milkova et al. 2016) to Chile (Pequeño 1989). Depth: surface to 2,161 m (7,088 ft) (min.: Personal communication: Scripps Institution of Oceanography Fish Collection, La Jolla, California; max.: Castellanos-Galindo et al. 2006b), and perhaps to 4,100 m (13,448 ft) (Personal communication: Los Angeles County Museum of Natural History Fish Collection, Los Angeles, California). The latter record of 4,100 m was based on the maximum depth fished by a midwater trawl and may represent a catch shallower than the maximum depth.