On soft sediments in sheltered places of the infralittoral, in salt as well as is brackish waters (euryhaline). Suspension feeder.
20-30m deep, off Doronatio, Toscana, W. Italy. 40mm.
At low tide, in mud, near Bordj el Hissar, Chergui island, Kerkennah archipelago, S. Tunisia. 16-17mm.
« Cardium glaucum: Testa cordata subantiquata antice glauca, costis viginti postice retrorsum imbricatis, natibus violaceis. » – J. G. Bruguière: Histoire naturelle des vers vol. I, Paris 1789. – 5m deep, Chioggia, Venezia, NE. Italy. 27mm.
The thin-shelled lengthened specimens of the Ponto-Caspian group are rather different from the thicker-shelled Atlantic-Baltic group that colonizes the western Mediterranean. For more information about the phylogenic separation of these two groups, see Nikula & Väinölä: “Phylogeography of Cerastoderma glaucum across Europe: a major break in the Eastern Mediterranean”, Marine Biology vol.143-2, january 2003, p.339-350.
5-6m deep, Vouliagméni marine lake, west of Perachóra, Loutráki area, N. Korinthia, Greece. 26-26,5mm.
One characteristic that helps to distinguish between C. glaucum and C. edule is the ribbing: visible at the inside in glaucum, while it is not in edule, whose shell is always thicker.
Two Amphipoda of the genus Centraloecetes Just 1983, trying to explore the mantle of a Cerastoderma glaucum at Leucate, Occitania, S. France. They inconvenience the animal so much that it cannot even expand its siphons serenely. Original picture provided by S. Clanzig (FR) – (CC BY-NC-SA).
