The oyster must be finished in claires at a density and for a duration rigorously defined by the regulations. It should be round and tightly shut, and correspond to an index of shape taking into consideration its length breadth and depth. The quantity of flesh is considered as a proportion of the total weight of the oyster.
This oyster should present a characteristic green tint from its time in the claire.
The green colour, so highly appreciated, is the result of the presence of the naviculus micro algae, filtered by the oyster which retains the pigment marennine.
This exceptional oyster is produced from October to May to respect its reproductive cycle and to guarantee them not to be milky.