Resumen en inglés

The richness and distribution patterns of the macroalgae, Rhodophyta and Ochrophyta in the south central zone of Tortuguilla Island were evaluated, covering three samplings in two hydrological periods, through a transect parallel to the coastline of 100m long and 2m wide. The samples collected in the field were washed, and continued with preservation in liquid and preservation in dry. They were fixed and preserved on permanent plates in 4% glycerinated gelatin solution and conservation of the specimens in dry condition, followed by a photographic record of each alga collected in macroscopic and microscopic view for its morphological and structural description. A total of 19 species were recorded, of which 12 belong to the Rhodophyta division and seven to the Ochrophyta division, grouped into seven families and 15 genera. The greatest richness of macroalgae was recorded during the dry season, with a total of 17 species, of which 11 were Rhodophyta and six were Ochrophyta, while fewer species were recorded in the rainy period, with three Rhodophyta. And seven Ochrophyta. It was found that the distribution patterns of the matroalgae were directly related to the type of substrate, hydrological periods and morphological adaptations, where, it was evidenced that in general there is a greater preference for hard rock substrates by the Rhodophyta and soft sandy divisions. By the Ochrophyta division. The homogeneity of the physical and chemical variations such as temperature, salinity and pH is highlighted, which had no impact on the development of macroalgae.