Laboratory germination and sea out-planting of tetraspore progeny from Kappaphycus striatum (Rhodophyta) in subtropical waters of Brazil

Tetrasporophyte green strains of Kappaphycus striatum introduced from the Philippines and cultivated in the sea at Ubatuba, São Paulo, Brazil, produced tetraspores in pilot mariculture experiments. In the laboratory, the released tetraspores showed high viability and 79% of germination, producing robust plantlets and large differences in morphology. After 5 months under laboratory culture, some of the plantlets that grew best were attached to ropes, transferred into the sea and monitored for 6 months. The results show the potential of the tetraspore progeny for strain selection and the economic feasibility for mariculture of K. striatum with fast adaptation to the sea and satisfactory growth rates of 6.4±0.4 to 4.3±1.2% day^-1.