La production de juvéniles de coquille Saint-Jacques (Pecten maximus (L.))

It is attempted to produce large quantities of 25 mm scallop juveniles suitable for restocking the beds. A first breeding experiment in laboratory gave a very low survival rate : about 1% from the D larvae stage to reach the size of 1 mm. The growth after metamorphosis is very irregular and slow, compared to the datas obtained in natural environment. An experimental programme of spat collection in natural environment, completed by hanging culture has been conducted. An average number of 300 spats (size 15 mm) per collector has been obtained in 1976. Banging culture allows to reach the size of 25 mm three months after settlement with a very good survival rate. The yield of a large number of spat from collectors seems to demonstrate that there is a future for this technique in areas of high concentrations of adult scallops. However for the depleted beds, hatchery raised spat might be used for redevelopment. But hatchery experiments at a bigger scale are needed to check the possibility of mass production of small spats which could be subsequently raised by hanging culture in natural environment.