The Conchological Society of Great Britain and Ireland
Helping to understand, identify, record, and conserve molluscs
Acmaea tessulata (O F Müller, 1776)Author & date of last revision: Steve Wilkinson on 10 July 2011
Collisella testudinalis; Acmaea testudinalis; Acmaea tessulata (O F M;
DescriptionConical shell up to 20mm long but usually smaller if it lives in the intertidal. It is cream, green or grey in colour with red brown markings. The inside is white with a chocolate coloured, horseshoe shaped headscar. The shell surface is reasonably smooth but has fine radiating and concentric lines. Key identification features
Similar species
Ecology and behaviourLives attached to stable stones with red algal growths (feeds on these). Eggs are laid in spring/summer attached in a mucus sheet. Distribution and statusCommon Northern species occurring in the northern half of British Isles to the north of Norway. Place cursor on underlined words for pop-up definition. View full POP-UP GLOSSARY. 
Image © Steve Wilkinson
Additional imagesGALLERY of larger images of this species. Recorded UK distribution |
