Etude comparative de la croissance et de l'activité écophysiologique des huîtres creuses Crassostrea gigas, Crassostrea angulata et des hybrides

A comparative study of the growth performances in cupped oysters Crassostrea gigas, Crassostrea angulata and their hybrids was conducted from March to October 1999 in a controlled farm with phytoplankton (Skeletonema costatum) input. The individuals, of the same age, were from genitors which had been identified through a marker analysis of the mitochondrial genome (Boudry et al, 1998). As a consequence, two pure offspring were obtained through the crossing of Portuguese oyster C. angulata (AA) genitors and the crossing of Japanese oyster C. gigas (GG) genitors. Two other offsprings were produced through the hybrid crossing of C. gigas female genitors with C. angulata (GA) male genitors on one hand, and C. angulata female genitors with C. gigas (AG) male genitors, on the other hand. The statistical analysis of the results showed major differences in the weight increase of the offsprings. Japanese oysters (GG) showed growth rates lA times higher than Portuguese oysters (AA). The hybrids' growth (GA et AG) was significantly higher than C. angulata (AA) but similar to C. gigas (GG).