Neptunomonas japonica is a species of bacteria.

[1] It is Gram-negative, rod-shaped, non-spore-forming and motile by means of a single polar or subterminal flagellum.

Its type strain is JAMM 0745T (=JCM 14595T=DSM 18939T).

It was first found in carcasses of a Sperm whale and is closely related to a symbiotic bacterial clone of the polychaete Osedax japonicus.

This Oceanospirillales article is a stub.