Skip to main content

Group size and individual ‘personality’ influence emergence times in hermit crabs

Broadhurst, Harvey Eliot; Morrell, Lesley J


Harvey Eliot Broadhurst


Many animals benefit from aggregating due to the anti-predator effects associated with living in groups. Hermit crabs are known to form groups, or ‘clusters’, which may occur at sites of high shell availability. Clustering may also have anti-predator benefits, if individuals in larger clusters able to spend less time engaging in defensive behaviours such as hiding in their shells. Here, we test the hypothesis that crabs in larger clusters will emerge faster from their shells after an elicited startle response in the European hermit crab (Pagurus bernhardus). We found that individuals were generally consistent in their emergence times across group sizes (displaying ‘personality’ in relation to emergence time), but that group size influenced emergence time in P. bernhardus. In contrast to the hypothesis, crabs in larger clusters had longer emergence times relative to their own emergence times in smaller clusters. Suggested explanations for this effect include intra-specific competition for the gastropod shells that hermit crabs inhabit, as well as the possible release of chemical cues by crabs in larger clusters.

Journal Article Type Article
Publication Date Jan 1, 2019
Journal Bioscience Horizons: The International Journal of Student Research
Print ISSN 1754-7431
Publisher Oxford University Press (OUP)
Peer Reviewed Peer Reviewed
Volume 11
Article Number hzy011
APA6 Citation Broadhurst, H. E., & Morrell, L. J. (2019). Group size and individual ‘personality’ influence emergence times in hermit crabs. Bioscience Horizons, 11, doi:10.1093/biohorizons/hzy011
Keywords Hermit crabs; Emergence time; Personality; Group size; Behavioural consistency; Pagurus bernhardus
Publisher URL


Article (423 Kb)

Copyright Statement
© The Author(s) 2018. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (,
which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

You might also like

Downloadable Citations