The ultrastructure of several dinoflagellates with emphasis on Gonyaulax polyedra Stein and Gonyaulax monilata Davis

Abstract

Six species of dinoflagellates were subjected to a general ultrastructural study. Usual eukaryotic organelles such as a porous, double-membraned nucleus, mitochondria, Golgi bodies, chloroplasts, vacuoles, and 9 + 2 flagellar structure were found. The organelles in each species were similar in structure, although minor differences existed in some species. Oil droplets and starch grains were scattered throughout the cells. Unusual features encountered were condensed chromosomes, trichocysts, fibrous vacuoles, circular mitochondria, a triple membrane-bounded plastid, a double membrane system enclosing the thecal plates, and evenly spaced tubules beneath the thecal membranes.