To develop mussel culture in the South Pacific and especially in French Polynesia, trials for producing spat of Mytilus viridis were conducted at the Centre Océanologique du Pacifique (Cap) of the Centre National pour l'Exploitation des Océans (CNEXO) in Tahiti. Spawning is attained through thermal stimulation. Larval rearing is conducted in 800-liter cylindroconical tanks. Every two days the water is changed and antibiotics are added as a preventive treatment. Monochrysis lutheri and an Isochrysis locally isolated are used as food. Metarmorphosis and settlement are achieved between the 10th and 17th days. A 15 m3 tank supplied with flowing water from a shrimp rearing pond is used for the pre-growth. The marketable spat size (7-8 mm, 40 mg) is reached in one month after settlement. The survival rate between D stage and marketable spat size is 10% and 2 million spat were produced. The actual hatchery, with six 800-liter tanks, should give 2 to 3.10(6) spat/month. [NOT CONTROLLED OCR]