The Conchological Society of Great Britain and Ireland | Helping to understand, identify, record, and conserve molluscs

A southern species occurring from the south of the British Isles to the Mediterranean Sea, the Black Sea, the Azores and the Canary Islands. It is a relatively uncommon species in Britain whose distribution is still poorly understood.

Acanthochitona fascicularis

The map provided here shows the distribution of the species based on Conchological Society data held by the National Biodiversity Network (NBN). See terms and conditions.

The following datasets are included:

Conchological Society of Great Britain & Ireland: marine mollusc records

Open an NBN Atlas interactive map of this data in a new window.

Ecology and behaviour

Lives on the underside of rocks and boulders usually lightly embedded in sand or gravel. When displaced from substrate, can roll into a ball [4]. It feeds by grazing material from the rock surface using its radula. Most common in the low shore or shallow subtidal areas but can occur to a depth of 70m.

Similar species

Acanthochitona crinita has a narrower girdle and more variable oval or tear drop shaped granulation on the valve surface.

Key identification features

Wide girdle with eighteen conspicuous tufts of colourless bristles.[5]
Tightly packed round granules on the valve surfaces [6]

References and links

Baxter, J.M. and Jones, A.M. 1987. Molluscs: Caudofoveata Solenogastres Polyplacophora and Scaphopoda. London.

Taxon details available from MolluscaBase (AphiaID 138677):

Acanthochitona fascicularis (Linnaeus, 1767)

The UK NBN Atlas entry for the species can be accessed via this link.

Taxon version key

[NBNSYS0000173555]

Sort order

470

Taxonomic group

Chiton

Read more about Acanthochitona fascicularis

Size: Up to about 60mm long - Britain's largest chiton. Shape: Very broad girdle with the shell making up 30-40% of the width.

Acanthochitona crinita

Distribution and status

Occurs from Norway to the Mediterranean and Adriatic seas [GBIF map]. It is found all around the coasts of Britain and Ireland and is not uncommon. While it sometimes occurs in very high densities it more generally found in relatively low numbers.