Description: This limpet is a grey-white with a dark red-brown tortoiseshell pattern that radiates from the apex of the shell. There are very fine radiating ribs on the outer surface of the shell. It can reach up to 2.5 cm. The edge of the mantle is cuprous green, with two rows of short tentacles. The head scar is chocolate brown.

Habitat: Found on bedrock and boulders on the lower shore. Seems to prefer surfaces with encrusting red algae. Reported down to depths of 50 m.

Distribution: Although this species is found on most coasts of Britain and Ireland it is a northern species and much more common in the northern areas of both Britain and Ireland.

Similar Species: Unlikely to be confused with any other species. There is also a white tortoiseshell limpet Tectura virginea.

Key Identification Features:

• Tortoiseshell pattern radiating from apex of shell.
• Very fine, radiating ribs on outer surface of shell.

Distribution Map from NBN: Testudinalia testudinalis at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Testudinalia testudinalis at iNaturalist World Species Observations database.

GBIF data for Testudinalia testudinalis

WoRMS: Testudinalia testudinalis at World Register of Marine Species. Accepted name: Testudinalia testudinalis (O. F. Müller, 1776). AphiaID: 234208.

Classification: Biota; Animalia; Mollusca; Gastropoda; Patellogastropoda; Nacellida; Lottioidea; Lottiidae; Testudinalia