Alive and dead shells mixed together in a sandy beach.
On the western side of the root of Quiberon peninsula, a wide sandy area stretches from Penthièvre fortress up to Etel river mouth. This is, leaning against a set of torrid dunes, the Long Beach, a place where low tides reveal an incredibly abundant wild life. Five car parks allow motorists to approach the sea across the desertic land that separates the beach from the road.
"La Grande Plage". Wild, cleaned, wide, facing the open sea. The wind and the sound of the waves suddenly jump at your face. Click in the pic to load a panoramic view (560Ko).
The beach in front of the Observatory. This part of the coast is named "La Falaise", the Cliff, even if no cliff can be seen here. If mechanical sand-cleaning is employed in the northern end near Kerhilio, this "Cliff" area remains safe, and, then, full of wild life.
Upper part of the intertidal slope. Many shells are washed ashore. The "Cliff" receives a huge population of golden Donax vittatus (da Costa, 1778), Lutraria lutraria (Linnaeus, 1758) and Mactra stultorum (Linnaeus, 1758). Some Naticids, also, like this little Euspira catena (da Costa, 1778).
Flood-tide. Waveletts cover the hot sand. Animals begin to leave their holes. Many living shells appear on places that were previously dotted by hundreds of dead valves. This layer, a mixture of sand and rotten organic debris, is like a cemetery. And, in fact, it smells. Shells live here, and die here. The flood will blow off everybody up to the shoreline.
Some of the species found in and on the sand at flood-tide:
Acanthocardia tuberculata
(Linnaeus, 1758)
Donax vittatus
(da Costa, 1778)
Lutraria lutraria
(Linnaeus, 1758)
Mactra stultorum
(Linnaeus, 1758)
Angulus tenuis
(da Costa, 1778)
Euspira catena
(da Costa, 1778)
Little crabs.
PORTUNIDAE Rafinesque, 1815: Portumnus latipes (Pennant, 1777). British Isles to Morocco, Azores to Canarias, Mediterranean, Black Sea. On fine sand, intertidal to 30m deep.
It burrows in sand in which it tends to disappear with its (most of time) excellent camouflage. Carapace ca. 2x2cm. A close species is P. pestai from Med. sea, whose carapace is wider than long. Sometimes, there is a white spot on the dorsum (see below).
Frontal margin with three teeth, the median one being the longest. Anterolateral margins with five smooth indentations; #2 and #4 very weak. Picture © Celine Hamm, Almere, Nederland.
The "Crab-surprise" game. Where will they climb? Picture © Celine Hamm.