Oscillatoria is a genus that includes simple filamentous cyanobacteria or blue-green algae. Under flowing freshwater, it develops a thin, bluish-green mucilaginous coating on the edges or surface of objects. Here, let’s explore more about the structure and reproduction of Oscillatoria.

Table of Contents

• Oscillatoria Classification
• Oscillatoria Structure
• Oscillatoria Reproduction
• Frequently Asked Questions

Oscillatoria Classification

Oscillatoria Structure

• Oscillatoria‘s plant body is called a thallus, and it is a single unbranched thread.
• It is made up of just one row of cells that develop into unbranched filaments with a gelatinous coating.
• Oscillatoria is rarely found alone and can either be connected or free-floating. Most species either create dense tangle masses or spongy sheets. The threads can be placed in parallel rows or woven together.
• The unbranched filaments of Oscillatoria are called trichomes. Each trichome has a mucilaginous sheath surrounding it. It is made up of a row of cells stacked one on top of the other. These cells are prokaryotic in nature.
• The width of the cells exceeds their length. Except for the terminal cell, which has a spherical or dome form, all of the trichome’s cells are similar to one another.
• The filament also comprises biconcave dead cells called separation discs or necridia. These dead cells are filled with mucilage. The small pieces of filaments present between adjacent necridia are called hormogonia.
• Cell Structure – Each cell is made up of an inner protoplasm, a middle plasma membrane, and an outside cell wall. Hemicellulose and pectin make up the rigid cell wall. The cell wall is a bi-layered structure and has many pores. A mucilage sheath also encircles the cell wall.
• The protoplasm is divided into an inner colourless portion termed centroplasm and an exterior pigmented portion termed chromoplasm. Many thylakoids are widely scattered throughout the chromoplasm.
• The chromoplasm also has small gas vacuoles and many photosynthetic pigments.
• Membrane-bound organelles are absent in these cells. However, small ribosomes and reserve food materials are present in the protoplasm.
• The nuclear material is composed of irregularly arranged DNA fibrils. Their nuclear material is called nucleoid as there is no outer nuclear membrane.
• Also, the cell structure somewhat resembles bacteria. Thus, Oscillatoria is also called cyanobacterium.

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Oscillatoria Reproduction

Reproduction in Oscillatoria occurs only through vegetative methods like fragmentation and hormogone formation.

Fragmentation is made possible by dead cells that divide a filament into distinct sections or hormogonium, which then proliferates.

Hormogonia or hormogones are produced in mature filaments under favourable conditions. Hormogonia are small fragments of filaments present between adjacent necridia (mucilage-filled dead cells). The hormogones are freely released into the water when the filament ruptures at necridia. They later multiply and form new filaments.

This was a brief note on the Oscillatoria structure. For more NEET related content, visit BYJU’S.

See more:

• Difference between Bacterial Photosynthesis and Plant Photosynthesis
• Blue Green Algae
• Algae Bloom
• Nostoc