Pholas dactylus Linnæus, 1758
Norway to Morocco, Mediterranean, Black Sea. Intertidal to 20m deep, burrowed in soft stones, tyres, sunken woods.
The species in T. Pennant: British Conchology vol. 4 plate XLII, London 1812, via BHL.
Synonyms: callosa, dactylina, hians, muricata, verrucosa
A poorly variable species, despite two named forms: “decurtata” and “gracilis”.
In soft intertidal limestone, Plage de la Concurrence, La Rochelle, Charente-maritime, W. France. 72mm.
The animal in G. S. Poli: Testacea utriusque siciliæ…, vol. IV, Parma 1791-1796, plate VII via BHL.
2-3m deep, in limestone, Mar Menor lagoon, Murcia, S. Spain.
According to Brian Cunningham Aparicio, this may be the only population existing in Murcia. 67mm.
Mar Menor, clay bottom. 51mm.
1m deep, in soft stone, Pesaro, Marche, E. Italy. 46mm.
Locally abundant in the Atlantic, the species becomes rare in Mediterranean.
Weakly sculptured specimen collected in mud at 30cm deep, Zakynthos island, Ionian archipelago, Ægean, Greece. 32mm.
Pholas dactylus in Forbes & Hanley: A history of British Mollusca and their shells vol. 4, London 1853, via BHL.
Pholas dactylus in T. Brown: Illustrations of the recent conchology of Great Britain and Ireland, London 1844.
« …on the posterior side of these [valves] is placed a long, spatuliform, plate-like, accessorial valve, affixed by the connecting membrane ; anterior side of the valves with rough, transverse, spinous striæ, terminating in a rounded beak, with a large gape at that side ; posterior side smooth, marked with lines of growth, and terminating obtusely ; external surface of an ochre-colour, but varying according to the colour of the substance in which it locates ; inside smooth, white ; below the umbones, a large, flat, curved tooth. »
The species in E. Donovan: The natural history of British shells, vol. IV, London 1802, plate CXVIII. – This wavy form with a big umbonal callosity (with respect to the general length) is at the origin of the epithet “callosa” given by Lamarck (Hist. Nat. An. sans vert. vol. VI p.46) after some drawings in Brookes (fig.7) and in Lister (pl.433). In fact, these shells are just slightly subadult: their valves are not completely developed posteriorly. Nota bene that the epithet callosa has since been attributed to G. Cuvier (Le règne animal vol. II: “Les Pholades”), but it was not possible for me to find out why.
The aforesaid form “callosa”.
In clay stone at 2m deep, Omis, Croatia. 22mm.
Original pictures provided by B. Cunningham Aparicio (ES).
A juvenile from Palavas-les-Flots, Gard, S. France. 2,7mm.
Original picture provided by S. Clanzig (FR) – (CC BY-NC-SA).
Specimens in a limestone from around the Cap Ferrat.
Musée des coquilllages (Association SOS Grand Bleu), Saint-Jean-Cap-Ferrat, Alpes-Maritimes, SE. France.

— back to Pholadidæ —