The zoospore ofPhlyctochytrium plurigibbosumBarr is globular to amoeboid while swimming and posteriorly uniflagellate. Mitochondria are in the posterior and are petal-like in their arrangement. The nucleus and one or more lipid globules are in the centre to anterior part of the cell. Morphologically, microbodies are intimately associated with lipid globules and loosely associated with mitochondria. There is a conspicuous double membrane system of smooth endoplasmic reticulum, and free ribosomes are dispersed throughout the cytoplasm. Microtubules radiate into the zoospore body from the proximal face of the kinetosome.