Cell walls of the centric diatom Auliscus (left) and the pennate
diatom Navicula (right). Navicula has a groove along the
longitudinal axis. This is involved in motility
As a basic principle centric und pennate forms are discriminated. Centric diatoms exhibit more than two symmetry axes, while pennate diatoms are bilateral-symmetric with two symmetry axes.
Diatoms
