Nostoc is a Colonial, filamentous
algae as mucilaginous balls that belongs to the class cyanophyceae (Blue green
algae)
Asexual Reproduction
1. Fragmentation: the colony breaks up into many pieces and each forms a
new colony or old trichomes breaks up into fragments and each forming new
filaments
2. Hormogonia: are short, small motile filaments with rounded ends. These
small filaments are without heterocyst and come out of the mucilage sheath,
undergo division and form new colonies
3. Akinetes: Large sized, unicellular, thick walled, resting spores with
plenty of reserve food in the cytoplasm
Highly resistant to high temperature and extreme environments
It can tide over unfavourable conditions
On return of favourable condition, it germinate to form new filaments
4. Heterocyst germination: In species like N.commune, heterocysts
serves as resting spores and directly germinate to form new filaments.
The protoplasm undergoes continuous division and forms a germling
On favourable condition, wall of heterocyst rupture and germling comes
out and forms a new trichome.
5. Endospores: Non flagellated, thin walled, naked spores formed within
cells by the division of protoplast.
Protoplast of the cell divides into small bits and each bit forms an
endospore
In species like N.commune
More on Nostoc: Nostoc Taxonomic position, Habitat and Cell structure
Heterocyst of Nostoc: Structure and Function
More on Nostoc: Nostoc Taxonomic position, Habitat and Cell structure
Heterocyst of Nostoc: Structure and Function
Tags:
Algae
nostoc akinetes
nostoc asexual reproduction
nostoc endospres
nostoc heterocyst
Nostoc reproduction