As of May-June, the oysters maturent by losing their winter lipidic reserves which will be replaced by the " milt ". With maturation the gonades inflate products gametic. This phenomenon is due to the change growing of temperature and the salinity of surrounding water.
Following an external shock, often a variation in temperature, a mollusc starts to lay by emitting a phéromone (hormone), incentive its congeneric to make the same thing. The male gamètes (spermatozoïdes) and females (ovules) fertilize themselves in the natural environment, i.e. the ocean. One speaks about external fecundation.
  Larval development  
  Refining into clear  
1 month 2 months 4 months
Fines the clear ones Special Growths into clear
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  Larval development:


At the end of 24 to 48 hours after the blossoming, the larva velligère begins with secréter its shell. It is nageuse (pelagic). At the end of 2 to 3 weeks, the foot appears: one speaks about larva pédivelligère, it is at this time that it seek to fix itself on any support which present. It is metamorphosed then in " small oyster ", one speaks about naissain.


In the neighbourhoods of July 14, the oyster culturists pose collectors on suitable grounds: they are supports of the varied types. With Marenne oyster, they use tubes in plastic, of the cups in figure threaded in cords, of the slate piles, the pieces of slates threaded in cords, of the " pléno " (rectangular supports filled of plastic blades).


18 months later, the naissain having grown bigger on the collector, one needs the détroquer: it is a question of taking off these small oysters. We call them then " grattis ".


It lasts 8 to 12 months. 2 techniques are used:
  • That is to say the grattis is sown directly on the ground of the grounds called " flat ", then fished to the fork 12 months later, to put them molluscs in breeding. During this period, it is necessary to harrow oysters so that they are not inserted in the mud, that they are oxygenated and push with a quite round form.
  • That is to say the grattis is put directly out of pockets on grounds known as " elevated ". It is a question of laying out the pockets on iron tables. It is regularly necessary to turn over the pockets and to type them to prevent that the oysters push in length and that they are not stuck in grid


It lasts 8 months. The oysters are put in pockets posed on iron tables, turned over to each tide.
The fact that this breeding is made on estran (zones which discovers with each low tide) returns them oysters very resistant to the exondation, because the adductor is very developed in order to retain water in the shell longest possible. To the end of the summer, beginning of the autumn, the oysters are brought back to ground, in order to refine them.


In order to obtain best oysters than you will find on the market, the oyster culturist carries out a refining into clear. This theirs the fine taste of soil and the color confer green so particular with our area. After a sorting, the oysters are put into clear. It is a question of respecting a density and a duration of refining.