Contribution à l'étude biologique de l'Huître dans le Bassin d'Arcachon, activité valvaire de Crassostrea angulata et de Crassostrea gigas; application à l'étude de la reproduction de l'Huître Japonaise

The biological study of the oyster is of a great interest for oyster culture and presents a wide field of investigation hardly addressed by scientists so far. This thought put forward by GALTSOFF in 1928, is still valid for the Portuguese oyster Crassostrea angulata (Lamarck); indeed, if many studies have been conducted on African species and, to certain extent on the Japanese oyster C.gigas (Thunberg) and the flat oyster Ostrea edulis (Linné), very few works deal with C. angulata from an experimental biological point of view. As highlighted by GHIRETTI (1960), molluscs show a greater physiological diversity than any other invertebrate philum; slight differences exist from one group to the other, and even sometimes between neighbouring species. We found it interesting to study the biology of the Portuguese oyster in the light of the experimental results obtained, mostly by American scientists. The C.gigas species, introduced in 1969 by French oyster farmers, slowly overrode the previous one after mass mortalities in the years 1970 and 1971. This evolution lead us to widen our field of investigation to a comparison between the two species as far as nutrition and reproduction are concerned. ... (unverified OCR)