Characteristics of the phylum Bacillariophyta:
i) They are unicellular, diploid, colonial or free living. One group of them (Pennales) live in fresh water and other group (Centrales) live in saline water of sea
ii) They are non-flagellated. but the gametes are motile
iii) They are ornamented in different ways
iv) Cell wall is enriched with silica and is well tined with salve (theca).
v) Chromatophores are yellow or golden-yellow, in which feucoxanthin and Diatomin are the main pigments
vi) Reserve food- Lipid and Volutine
vii) Reproduction: Vegetative reproduction by cell division, Asexual reproduction by auxospore and sexual reproduction by conjugation.