Transmission electron micrographs of Apiochytrium granulosporum sp. nov. (X-124 CCPP ZIN RAS). (A) immature sporangium with open papilla, several nuclei, and without lipid globule. Arrowheads show developing cell borders, (B) sporangium with mature and releasing zoospores, (C) intrasporangial zoospore. Arrowhead shows a fibrillar bridge between centriole (c) and kinetosome (k). (D) longitudinal section of centriole adjacent to kinetosome which is obliquely sectioned here. Arrowheads show a posterior root of two microtubules. aw = algal cell wall; c = centriole; fl = flagellum; k = kinetosome; l = lipid globule; m = mitochondrion; n = nucleus. Scale bars: A—2.5 µm, B—2 µm, C—200 nm, D—200 nm.