Ultrastructural characterization of Minutocellus polymorphus (Cymatosiraceae, Bacillariophyta) and first record from the Eastern Pacific

The diatom Minutocellus polymorphus is a widely studied species because it is an ideal model for toxicity tests since it grows rapidly. Although the gross morphology has been extensively described, the ultrastructural characters associated with its importance, are unknown. It is also the only species in the genus that has been documented in the North American Atlantic, but unknown on the Eastern Pacific coasts. In a collection made in Acapulco Bay, Guerrero, Mexico, cells morphologically identical to M. polymorphus were isolated. From cultures and observations in transmission electron microscope, a first description of the ultrastructure of the genus is provided, and from sequences of 18S, we confirmed its taxonomic identity as M. polymorphus. However, more detailed studies are needed to continue increasing the knowledge about the ultrastructure of diatoms on the Mexican Pacific coasts, where they are previously unknown.

Automated summary

The diatom Minutocellus polymorphus is a widely studied species that is an ideal model for toxicity tests due to its rapid growth. Although its gross morphology has been extensively described, the ultrastructural characters associated with its importance are unknown. Through a collection made in Acapulco Bay, Guerrero, Mexico, cells morphologically identical to M. polymorphus were isolated, and a first description of the genus' ultrastructure was provided through cultures and observations in a transmission electron microscope. Further detailed studies are needed to increase knowledge about the ultrastructure of diatoms on the Mexican Pacific coasts where they are previously unknown.