New records of macroalgae for the Mexican Atlantic and floristic richness of the Mexican Caribbean

Macroalgae samples from a habitat uncommonly analyzed (next to the basal part of live tissue of the corals Acropora palmata and Diploria strigosa), and from a Mexican zone barely known floristically (the southern part of the Mexican Caribbean) were studied. Based on those samples, Corallophila verongiae (Rhodophyta), Derbesia fastigiata, (Chlorophyta), and Hincksia onslowensis (Phaeophyta) are recognized as new records for the Mexican Atlantic coast. Similarly, Lophosiphonia obscura (Rhodophyta) is recognized as a new record for the continental coast of the Mexican Atlantic, since the previous solitary record (more than 40 years ago) was from the Alacran reef, in the open ocean, approximately 180 km away from Puerto Progreso, Yucatan. Even though the four macroalgae species were sterile, the morphological characters allowed their identification. Considering these new records, the total number of macroalgae species registered up to this study for the Mexican Caribbean is 546, including 307 Rhodophyta, 171 Chlorophyta, and 68 Phaeophyta. Both, this tropical Caribbean zone, and the temperate coast of Baja California represent the two richest macroalgae marine zones of Mexico.