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In this article we will discuss about the thallus and cell structure of hydrodictyon with the help of suitable diagrams.
Thallus Structure of Hydrodictyon:
A mature coenobium consists of a hollow cylindrical network which is closed at both the ends (Fig. 1). It is flat and saucer shaped and its maximum size is generally 20-30 cm. Rarely it may reach up to a length of 60 cm. The mature net of coenobium is made up of a few hundred to several thousand cells.
These cells are joined at the end and form pentagonal or hexagonal structures. These structures are called meshes. Bach mesh interspace is generally bounded by 5-6 or rarely three cells. At each angle of the net or mesh meet three cells (Fig. 2 A, B).
Cell Structure of Hydrodictyon:
Each cell is long, cylindrical or ovoid in shape. Its internal structure can be differentiated into two parts: cell wall and protoplasm. Cell wall is two layered and is made up of cellulose. It encloses protoplasm. When young, the cells are uninucleate, but at maturity they become multinucleate (coenocytic).
Cells contain reticulate chloroplast with many pyrenoids (Fig. 2C). All the typical structures of green algae like ribosomes, mitochondria, dictyosomes are also present. As the cell matures, a central vacuole appears and the protoplasm becomes peripheral.
