Key to the species of Caristiidae in Japan (modified from Okamoto et al. 2014)

1a. Lateral line present, with enlarged pored scales ........... 2

1b. Lateral line absent, without enlarged pored scales....... 3

2a. Anal-fin rays 20–22; total vertebrae 36–39; body color beige............................................... Platyberyx andriashevi

2b. Anal-fin rays 18–19; total vertebrae 33–34; body color brown ..................................................... Platyberyx rhyton

3a. Suborbital series expanded, overlapping bones of upper jaw and forming broad space between orbit and mouth; upper jaw short, extending approximately to mid-orbit ............................................................................................. 4

3b. Suborbital series not expanded, space between orbit and mouth narrow; upper jaw long, extending to posterior margin of orbit ........................ Caristius macropus

4a. Dorsal-fin origin posterior to orbit; jaw teeth arranged in multiple rows ........................ Paracaristius maderensis

4b. Dorsal-fin origin above orbit; jaw teeth arranged in single row, except near symphyses.......................................... ........................................................ Paracaristius nudarcus