A. japonicus

A. japonicus may refer to:
 * Acetes japonicus, a shrimp species
 * Achaeus japonicus, the orang-utan crab
 * Aedes japonicus, a mosquito species
 * Analipus japonicus, a brown alga species
 * Apostichopus japonicus, a sea cucumber species
 * Argyrosomus japonicus, the mulloway, jewfish or dusky kob, a fish species found in coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan