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Key to Irish Chitons
Species Description


Acanthochitona fascicularis  (Linnaeus, 1767) [back to the Key] | [species list] | [previous]
Length: to 60 mm – the largest Irish chiton

Tegmentum colour: typically olive green with reddish blotches; the wide jugal area is usually be lighter (cream or beige) with dark longitudinal streaks.

Sculpture: valves little or not beaked. The jugal area with faint longitudinal grooves; latero-pleural areas covered in closely-spaced, small round granules arranged in radial rows.

Girdle: very broad and densely covered with two kinds of spicules: short slender spicules and longer spicules interspersed between them, with 18 large tufts of spines arranged around the head and at the sutures.

Bathymetric range: low-water to 50 m; lives sub-tidally on rock and in crevices.

Geographic range: Found in the north Atlantic from Ireland and Britain south to the Mediterranean and Adriatic.

Similar species: Acanthochitona crinita; Acanthochitona discrepans


Taxonomy & Synonymy:

ORDER: Chitonida Thiele, 1909

FAMILY: Acanthochitonidae Pilsbry, 1893


Acanthochitona fascicularis (Linnaeus, 1767)


References: Vončina K, Mikkelsen NT, Morrow C, Ang R, Sigwart JD (2023) Clarification of the taxonomic status of Acanthochitona discrepans (Brown, 1827) with new data for the North-East Atlantic Acanthochitona (Polyplacophora, Acanthochitonidae). Biodiversity Data Journal 11: e109554.


List of synonymised names available at:


For more information on this species, see:

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