Skip to main content

Research Repository

Advanced Search

Internet 'shellebrity' reflects on origin of rare mirror-image snails

Internet 'shellebrity' reflects on origin of rare mirror-image snails Thumbnail


Professor of Evolutionary Genetics

Philippe Thomas


While animal bodies are typically bilaterally symmetric on the outside, the internal organs nearly always show an invariant left-right (LR) asymmetry. In comparison, snails are both internally and externally LR asymmetric, outwardly obvious in the shell coiling direction, or chirality. Although some species of snail are naturally variable for chirality, sinistral individuals occur very rarely in most species. The developmental and genetic basis of these rare mirror-imaged individuals remains mysterious. To resolve this issue, the finding of a 'one in a million' sinistral garden snail called 'Jeremy' was used to recruit citizen scientists to find further sinistral snails. These snails were then bred together to understand whether their occurrence is due an inherited condition. The combined evidence shows that rare sinistral garden snails are not usually produced due to a major effect maternal Mendelian locus. Instead, they are likely mainly produced by a developmental accident. This finding has relevance to understanding the common factors that define cellular and organismal LR asymmetry, and the origin of rare reversed individuals in other animal groups that exhibit nearly invariant LR asymmetry.


Davison, A., Thomas, P., & ‘Jeremy the snail’ citizen scientists. (2020). Internet 'shellebrity' reflects on origin of rare mirror-image snails. Biology Letters, 16(6), Article 20200110.

Journal Article Type Article
Acceptance Date May 1, 2020
Online Publication Date Jun 3, 2020
Publication Date Jun 1, 2020
Deposit Date Jun 7, 2020
Publicly Available Date Jun 8, 2020
Journal Biology letters
Electronic ISSN 1744-957X
Publisher Royal Society, The
Peer Reviewed Peer Reviewed
Volume 16
Issue 6
Article Number 20200110
Keywords Agricultural and Biological Sciences (miscellaneous); General Agricultural and Biological Sciences
Public URL
Publisher URL
Additional Information Received: 2020-02-20; Accepted: 2020-05-01; Published: 2020-06-03


You might also like

Downloadable Citations