Polyphasic assessment of the bloom-forming cyanobacterial species Limnoraphis robusta (Oscillatoriaceae) and Microcystis aeruginosa (Microcystaceae) in a Mexican subtropical crater lake

Abstract

The main element to assess the potential risks associated with toxic cyanobacterial blooms is the precise\xa0identification of the species. As part of a water quality monitoring during 2015 in Santa Maria del Oro crater lake,\xa0Nayarit, a cyanobacterial bloom was detected. Thus, this work aimed to identify the bloom-forming cyanobacteria\xa0species using a polyphasic approach. The cyanobacteria that produced the bloom were Limnoraphis robusta , which\xa0represented the first record for Mexico, and Microcystis aeruginosa , which is a new record for Nayarit. During the\xa0bloom’s most intense phase in March and April, the filament and trichome width of L. robusta decreased by 50%, thus,\xa0resembling L. hieronymusii morphometry. Despite morphological variations, ecological and molecular data allowed us\xa0to assign, unambiguously, the morphotype to L. robusta . According to our data, it is important to trace the cell size of natural populations to assess their morphological variation limits.