Background.

Illustrated records of the Podolampadaceae from Mexican waters are scarce.

Goals.

To study the thecal morphology of the genera Blepharocysta and Podolampas and to document the occurrence of planktonic species in both Atlantic and Pacific waters around Mexico were the main objectives of the present study.

Methods.

Bottle and net samples were taken from the water column in the southern Gulf of California (Baja California Sur state) and the southern Gulf of Mexico (Veracruz and Yucatan states) from 2008 to 2019. Light and scanning electron microscope (SEM) photos were taken, and observations on thecal morphology of the podolampadaceans were made.

Results.

Thecal morphology of Blepharocysta denticulata, B. okamurae, B. paulsenii, B. splendor-maris, Podolampas bipes, P. elegans, P. palmipes, P. reticulata and P. spinifera was examined; SEM micrographs of seven species are shown. Blepharocysta cells exhibited a wide variation of thecal features. Short descriptions are accompanied by references to publications that contain illustrations. The history of the study of the podolampadaceans is presented.

Conclusions.

Morphological data are not sufficient to confirm the status of some doubtful podolampadaceans or to clarify infraspecific, species and generic relationships within the family; therefore, molecular data are necessary.