Diodora graeca

{{Short description|Species of gastropod}} {{Speciesbox | image = Diodora graeca 01.jpg | image_caption = | taxon = Diodora graeca | authority = (Linnaeus, 1758) }}

'''''Diodora graeca''''', the '''Greek keyhole limpet''', is a sea snail or limpet, a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets.<ref name="WoRMS">{{WRMS species|139951|''Diodora graeca'' (Linnaeus, 1758)||17 December 2018}}</ref>

It was originally described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae'' as ''Patella graeca'' (basionym).

==Distribution== This keyhole limpet can be found beneath stones and clinging to rocks in the sublittoral zone (up to a depth of a few hundred meters) in the Mediterranean and West Africa to the North Sea (widespread on the coasts of Ireland and western Britain) and the subarctic North Atlantic. The specimens washed up on the beaches of the North Sea are almost certainly fossils (from the Pliocene and the Eemian), as this species no longer occurs in the south-eastern part of the North Sea.<ref>Oliver, A.P.H. (2004). ''Guide to Seashells of the World.'' Buffalo: Firefly Books. 25.</ref>

==Description== The oval shell is small (25 mm long and 18 mm wide) and rather flat. It has no whorls and is shield-shaped. The base of the shell is somewhat bent. Its aperture is situated at the dorsum and is keyhole-shaped. This hole serves as an outlet for water and waste products. The shell has a slight reticulated sculpture with concentric cords crossed by radial ridges and with the alternate ridges larger. The color of the shell varies from creamy white to yellow white and is often slightly orange tinted.

This species is mainly herbivorous and also feeds on detritus. The animal has a broad creeping foot and a developed mantle. Its carotenoid content has been investigated and the following substances have been found : α-, β, γ-carotene, zeaxanthin, diatoxanthin, mutatoxanthin and astaxanthin.<ref>{{cite journal|last=Czeczuga|first=Basyli|title=Carotenoid contents in Diodora graeca (L.) (Gastropoda: Fissurellidae from the Mediterranean (Monaco)|journal=Comparative Biochemistry and Physiology B|year=1980|volume=65|issue=2|pages=439–441|doi=10.1016/0305-0491(80)90045-0}}</ref>

==Synonyms== *''Fissurella mamillata'' Risso, 1826 *''Fissurella reticulata'' (Da Costa, 1778) *''Patella apertura'' Montagu, 1803 *''Patella graeca'' Linnaeus, 1758 *''Patella reticulata'' Donovan, 1803

==References== {{Reflist}}

==Sources== {{Commons category|Diodora graeca}} * Oliver APH, The Hamlyn Guide to Shells of the World, Hamlyn Publishing Group, 1975, {{ISBN|0-600-56577-7}} * Rolán, E., 2005. Malacological Fauna From The Cape Verde Archipelago. Part 1, Polyplacophora and Gastropoda. * Muller, Y. (2004). Faune et flore du littoral du Nord, du Pas-de-Calais et de la Belgique: inventaire. [Coastal fauna and flora of the Nord, Pas-de-Calais and Belgium: inventory]. Commission Régionale de Biologie Région Nord Pas-de-Calais: France. 307 pp. * Backeljau, T. (1986). Lijst van de recente mariene mollusken van België [List of the recent marine molluscs of Belgium]. Koninklijk Belgisch Instituut voor Natuurwetenschappen: Brussels, Belgium. 106 pp.

Category:Diodora Category:Gastropods described in 1758 Category:Animal taxa named by Carl Linnaeus Category:Molluscs of Africa Category:Molluscs of the Atlantic Ocean Category:Molluscs of the Mediterranean Sea