The transplantation of Gracilaria for the establishment of cultivation centres has been a common practice in Chile. but so far differences in the initial transplants and their eventual morphologies have not been noted. Subtidal populations of Gracilaria obtained in the Maullin area (41-degrees-34'S, 73-degrees-39'W) were initially morphologically different from intertidal Gracilaria populations collected in the Quillaipe area (41-degrees-33'S, 72-degrees-45'W). Both populations were grown under the same experimental intertidal conditions in Metri Bay (41-degrees-36'S, 72-degrees-42'W). After several months of cultivation. the morphological differences still existed. Significant differences in the yield and gel strength of agar. and susceptibility to epiphytism. were found. However. no differences were detected in the productivity of each initially different population. This evidence indicates that the success of Gracilaria farming will depend on the origin of the initial Gracilaria inoculum.