noun
tardigrade; water bear
A microscopic, water-dwelling animal known for its extreme resilience. In Japanese, the katakana form クマムシ is the most common spelling.
クマムシは乾燥や放射線に強いことで知られている。
Tardigrades are known for their resistance to desiccation and radiation.
顕微鏡でコケの中のクマムシを観察し
I observed tardigrades in the moss under a microscope.
Compound of 熊 (kuma, 'bear') + 虫 (mushi, 'bug'), from the animal's bear-like appearance under a microscope. The exact origin of the name is uncertain, but it is a calque of the English 'water bear'.