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Water Bears: Tardigrada

Giant Yellow Water Bear (richtersius Coronifer): Species Account

Physical characteristics: This species is a relatively large (up to 0.039 inches or 1 millimeter) water bear. They are usually yellow to orange with large black eyes. Each leg has two equally sized claws.

Geographic range: This species is found in the Arctic, Sweden, Turkey, Nepal, and Colombia.

(Specific distribution map not available.)

Habitat: Giant yellow water bears live on mosses in high mountain habitats up to 18,300 feet (5,600 meters) and in Arctic habitats.

Diet: This species is believed to suck fluids from the cells of mosses.

Behavior and reproduction: Giant yellow water bears can survive severe dehydration for up to 9 years. They are also capable of tolerating temperatures down to -320°F (-196°C) whether they are in the tun stage or not.

This species requires males and females to reproduce, but can also switch to parthenogenesis.

Giant yellow water bears and people: This species has possible uses as an experimental animal in outer space. They are capable of surviving high temperatures, vacuum, and cosmic radiation.

Conservation status: Giant yellow water bears are not considered endangered or threatened. ∎



Kinchin, Ian M. The Biology of Tardigrades. London: Portland, 1994.


Romano, F.A. "On Water Bears." Florida Entomologist 86 (2003): 134-137.

Wright, J. C., P. Westh, and H. Ramløv. "Cryptobiosis in Tardigrada." Biological Reviews of the Cambridge Philosophical Society 67 (1992): 1-29.

Web sites:

Hunting for Water Bears in the Backyard. http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjun00/mmbearp.html (accessed on January 19, 2005).

The Incredible Water Bear. http://www.microscopy-uk.org.uk/mag/index-mag.html?http://www.microscopy-uk.org.uk/mag/artjun00/mmbearp.html (accessed on January 19, 2005).

Water Bears-Tardigrades. http://www.tardigrades.com (accessed on January 19, 2005).

Additional topics

Animal Life ResourceMollusks, Crustaceans, and Related SpeciesWater Bears: Tardigrada - Physical Characteristics, Behavior And Reproduction, Water Bears And People, Giant Yellow Water Bear (richtersius Coronifer): Species Account - GEOGRAPHIC RANGE, HABITAT, DIET, CONSERVATION STATUS