In this article we will discuss about:- 1. Occurrence of Microcystis 2. Thallus Organisation of Microcystis 3. Reproduction.
Occurrence of Microcystis:
Microcystis (Gr. Micro = small; kystis = bladder) is a colonial fresh water alga. It is represented by 18 species. All species are free floating, and form extensive water blooms. This alga secretes poisonous substances. These substances destruct the liver and inhibit the growth of other algae.
M. aeurginosa is responsible for the production of a toxin (fast death factor) which is toxic to many animals which drink water containing this alga. M. toxica is very poisonous and is responsible for the death of thousands of sheep’s and catties.
Thallus Structure of Microcystis:
Thallus is in the form of colonies. The colonis are free floating and irregularly covered by colourless, mucilaginous sheath. The colony contains large number of very small cells which are spherical, elongated or ellipsoidal and lack individual sheaths.
Gas vacuoles are commonly present in the colony. Each cell has a cell wall and a protoplasm which is differentiated into peripheral chromatoplasm and a central portion called centroplasm or nucleoplasm. The central body represents an incipient nucleus.
Reproduction in Microcystis:
The reproduction takes place by cell division which is seen to take place in all directions. The whole colony also multiplies by fragmentation. Reproduction by nannocytes is also reported in M. flosaquae.