Background.

Chichancanab Lake is one of the most important freshwater ecosystems located in the center of Yucatan peninsula (Mexico) as it is a primary hydrological ecoregion and habitat for endemic fauna species. However, its diversity of freshwater algae is poorly known, including cyanobacteria, a group that is of interest for its potential function as an indicator.

Objective.

Document the diversity of the cyanobacteria present in this site.

Methods.

Three samplings were carried out in different seasons of the year. The collection of freshwater algae was carried out directly. The samples were analyzed by light microscopy and diagnostic characteristics were collected depending on the taxa. Species were identified with specialized literature, in some cases the nomenclature was updated, and a review of its regional diversity was carried out.

Results.

In this study, 29 species of cyanobacteria belonging to different orders are reported, of which Synechococcales and the families Merismopediaceae (Synechococcales) and Oscillatoriaceae (Oscillatoriales) stand out. We report 18 new records for Quintana Roo, of which 11 are for Yucatan Peninsula: Synechococcus ambiguus, Eucapsis aphanocapsoides, E. parallelepippedon, Romeria hieroglyphica, Jaaginema subtilissimum, Komvophoron minimum, Planktolyngbya limnetica, Schizothrix tenuis, Spirulina nordstedtii, Phormidium californicum y P. lucidum. The ecological conditions of the site are similar to other tropical water bodies in different Caribbean countries and share at least 31.4% of morphospecies.

Conclusions.

A greater diversity of cyanobacteria than previously reported in the literature was found. This work intends to lay the foundations for the knowledge of freshwater algae in the lagoon and be a reference for future taxonomic, ecological, and applied works that start from this place.