tardigrade: Quick Facts

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Last updated

Oct. 14, 2026

Facts

Also Known As	water bear • moss piglet • Tardigrada

Photos and Videos

Infographic of a tardigrade, or water bear, with close-ups of its toothed mouth, egg-filled saclike ovary, clawed legs, and four pairs of limbs. Labels explain that tardigrades lack respiratory and circulatory organs, use body fluid to transport oxygen and nutrients, and can enter a dehydrated dormant state called a tun.

Tardigrade (Macrobiotus)

Microscope image of a tardigrade moving among elongated green algal cells on a pale background.

A tardigrade and a nematode

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Topics

Extremophile Eumetazoa annelid echinoderm sponge flatworm cnidarian arthropod mollusk moss animal lamp shells Chordate

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