Note
Studies on the biodiversity of marine phytoplankton in Costa Rican coasts are sparse and mostly confined to the Pacific coast. More specifically 10 the Golfo de Nicoya. New records presented here come from the three most important embayments in the Pacific coast. We report 268 species, 258 for the Pacific coast, 53 for the Caribbean coast, and 43 species common to both coasts. There are no reports of coccolithophorids, and only few species of flagellates other than dinoflagellates have been identified.