Life Cycle Of Sargassum
Classification
Sub- division Algae
Class- Phaeophyceae
Order- Fucales
Family- Sargassaceae
Genus- Sargassum
Thallus
Study the external structure of thallus.
1. Thallus is erect, thalloid and branched.
2. It remains attached to the substratum by a discoid holdfast.
3. Main axis stands out from the holdfast. The height varies from a few centimeters to many centimeters.
4. Main axis bears large number of primary laterals forming a larger part of vegetative structure. Branches are radially symmetrical and spirally arranged.
5. Secondary branches are repeatedly branched.
6. Many branches are flattened along the plane of branching into leaf-like structures called 'leaves'.
7. Leaves are narrow and their margins are mostly serrate. A few species also show a clear mid-rib.
8. In the lower parts, leaves are replaced by air bladders. However, leaf or its part is modified almost at any place into an air bladder.
9. Leaves show minute pores on both of the surfaces which are ostioles (or openings) of conceptacles (sterile) or cryptostomata or cryptoblasts.
10. In the axils of foliaceous branches (leaves) is situated a series of repeatedly branched receptacles which bear reproductive structures.
Axis
Place a small piece of axis in the pith after removing the leaves.
Cut a T.s., stain in safranin and mount in glycerine to study the internal structure.
