Study
Survival of the stillest: predator avoidance in shark embryos
Kempster, Ryan M.; Hart, Nathan S.; Collin, Shaun P.
PLoS ONE, 2013
Bamboo shark embryos, still inside translucent egg cases, were exposed to weak electric fields mimicking those of an approaching predator. Gill movement and the rhythmic tail undulation that flushes water through the case were recorded.
- Studied in
- Chiloscyllium punctatum
- Sample size
- shark embryos in egg cases exposed to simulated predator electric fields
Embryos ceased gill movement and froze within seconds of detecting the field, holding still until it passed. The response was present well before hatching.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Electroreception is functional in shark embryos and drives an anti-predator freeze response before the animal has ever encountered a predator.
How NatureHQ reads it
An unborn animal recognising a predator by its electric field, and knowing to stop moving, is about as clear a demonstration as exists that this sense is neither learned nor incidental. It also inverts the usual framing of electroreception as a hunting sense — here it is being used defensively, by an animal in an egg, which suggests the sense arrived for reasons broader than predation.
- One oviparous species with a translucent egg case chosen for observability.
- Simulated fields are simplifications of a real predator.
- Whether the response improves survival in the wild is inferred rather than measured.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Public Library of SciencePublished in a PLOS journal under CC BY 4.0.
doi.org/10.1371/journal.pone.0052551
This reference was resolved automatically against Crossref on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-10.