This is a list of mammal species recorded in Japan (excluding domesticated and captive populations).
[4] The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature: Sirenia is an order of fully aquatic, herbivorous mammals that inhabit rivers, estuaries, coastal marine waters, swamps, and marine wetlands.
Shrews and solenodons resemble mice, hedgehogs carry spines, gymnures look more like large rats, while moles are stout-bodied burrowers.
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight.
Cetaceans are the mammals most fully adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.