Habitat: Navicula usually lives in water floating, such as pond, river etc. individually or in a group. A few species of them live in saline water.
Structure:
i) Navicula is a unicellular organism
ii) Each cell contains a definite nucleus, a central vacuole, a densed cytoplasmic layer and one to many golden chromatophores A complete cell is called frustules.
iii) From frontal view, it is rectangular in shape, but from lateral stew it seems to be a boat (Broad at themiddle tapering at the ends)
iv) A lot of long lines are seen in cell wall. Cell wall consist of the small valve (Hypotheca)
V) Reserve food is lipid
vi) Reproduction: By cell division (vegetative) by Auxospore (asexual) by conjugation (sexual reproduction).
