Study
Cryptobiosis — a peculiar state of biological organization
Clegg, James S.
Comparative Biochemistry and Physiology Part B, 2001
Reviews the evidence for ametabolic survival, drawing heavily on brine shrimp cysts, and examines what remains structurally intact in an organism whose metabolism cannot be detected.
- Studied in
- Artemia franciscana, Tardigrada, Rotifera, Nematoda
- Sample size
- review
In the deepest cryptobiotic states no metabolism can be measured by available methods, and the organism’s survival depends on the physical preservation of its structures rather than on any ongoing repair.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Cryptobiosis is a third state alongside life and death in the ordinary senses, defined by organisation persisting without process.
How NatureHQ reads it
Paired with Keilin to set the honest limit: what is established is that no metabolism can be *measured*, and detection limits are not zero. NatureHQ states the claim in those terms, which is more interesting than the tidier version.
- The central negative claim is bounded by measurement sensitivity, which the author is explicit about.
- Brine shrimp cysts are exceptionally well studied and may not represent every cryptobiotic organism.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Extreme survival
No animal is immune to anything. Every demonstrated survival of an extreme came from a particular starting state, lasted a measured time, and killed some fraction of the animals tested.
Cryptobiosis
In the deepest dried states, no metabolism can be detected at all — and that is the honest way to say it. Whether metabolism has genuinely stopped or is simply below what instruments can see is still open.
Published by: Elsevier journalsPublished in an Elsevier journal.
doi.org/10.1016/s1096-4959(01)00300-1
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-03.