Peridinium gutwinski is a dinoflagellate species found in marine and freshwater environments. It has round to oval cells covered with cellulose thecal plates. The organism features two flagella: one encircling the cell and another trailing behind. Peridinium gutwinski is photosynthetic, contributing to the food webs as a primary producer. It can vary in color and size, typically ranging from 20 to 200 micrometers in diameter. Monitoring its populations helps assess water quality, and some dinoflagellates, including certain species of Peridinium, can produce toxins affecting shellfish and causing harmful algal blooms.