HYDRODICTYON

CLASSIFICATION OF HYDRODICTYON​

Sub-division :- Algae

Class :- Chlorophyceae

Order :- Chlorococcales

Family :- Hydrodictyaceae

Genus :- Hydrodictyon

GENERAL CHARATERSTICS OF HYDRODICTYON​

• The thallus is a multicellular colony forming a net-like structure.
• Colony is a hollow and sac-like or saucer-like (saccate), cylindrical network, closed at both the ends. 
• The spaces of the reticulum are bound by five or six cells (this number varies between 3-10 cells) which form a pentagonal or hexagonal structure.
• The cells are cylindrical. End walls are angular to facilitate the formation of a mesh. 
• A cell has a large central vacuole. 
• Cytoplasm lies towards the periphery.
• Cells are multinucleate. The young cells are however, uninucleate. 
• Cell is called a coenocyte because of its multinucleate nature and presence of large central vacuole. 
• Young cells have zonate or entire chloroplast. Little mature cells possess reticulate chloroplast. However, during older stages chloroplast may assume discoid shape and diffuses throughout the cytoplasm. 
• Chloroplast contains large number of pyrenoids.

IDENTIFICATION

1. Sub-division– Algae
   1. Presence of a simple thallus.
   2. Chlorophyll present
   3. Cell wall made of cellulose.
2. Class – Chlorophyceae
   1. Presence of a definite nucleus
   2. Chloroplast present. grass green colour
   3. Presence of starch
   4. Reproductive structure motile and flagella equal in length.
3. Order – Chlorococcales
   1.  Cells mostly single; if united form non filamentous colonies of definite shape and size
   2. Cells uni- or multinucleate
   3. Asexual reproduction by zoospores or autospores,
   4. Sexual reproduction isogamous.
4. Family – Hydrodictyaceae
   1. Cells united to form coenobe
   2.  Reproduction by zoospores and biflagellate gametes.
5. Genus – Hydrodictyon
   1.  Coenobe a saccate reticulum
   2. Chloroplast reticulate or discoid
   3. Uni- or multinucleate coenocytic cells.

REFERENCES

• https://en.wikipedia.org/wiki/Water_net