Trachichthys japonicus Döderlein, 1883 Gephyroberyx japonicus, the big roughy or blueberry roughy, is a species of fish in the family Trachichthyidae.

[2] It is endemic to the northwest Pacific off Japan, Taiwan and Hawaii,[2][3][4] and can be found at depths between 300 and 1,500 m (980–4,920 ft).

[5] It can reach 30–35 cm (12–14 in) in length.

[6] Based on broadly overlapping morphological features it is sometimes (e.g., by IUCN) considered a synonym of G.

[1][4][7] It is sometimes seen in deep-sea exhibits in public aquariums and it has spawned in captivity.