Oscillatoria (Simplified)

Oscillatoria is a freshwater blue-green algae belonging to the class Cyanophyceae. It is a prokaryotic organism.

The vegetative thallus is a haploid gametophyte. The alga is named Oscillatoria because the tip of the trichome exhibits pendulum-like oscillating movement. The thallus consists of an unbranched trichome with uniseriate filaments surrounded by a mucilaginous sheath. The trichome is composed of closely arranged uniform cells, and the terminal cell has a thickening at the apex known as a cap or calyptra. The filament contains necridia and hormogone.

Each cell in the filament is structured with an outer cell wall, a middle plasma membrane, and an inner protoplasm. The cell wall is composed of pectin and cellulose, with the plasma lying beneath it. The protoplasm is differentiated into an outer chromoplasm and an inner centroplasm containing pigments, pseudovacuoles, thylakoids, and reserve food materials, such as Cyanophycean starch and B-granules. The nuclear material in Oscillatoria is not surrounded by a nuclear membrane, hence referred to as nucleoid or incipient nucleus. The nutrition process is photoautotrophic, utilizing photosynthesis.

The growth of Oscillatoria occurs through amitotic division of intercalary cells of the filament. The alga exhibits three types of movements: Gliding movement or axial movement, oscillatory movement, and bending movement or tip revolving movement.

Oscillatoria reproduces through vegetative methods, including fragmentation and hormogone formation. However, sexual reproduction is absent, and there is no alternation of generations in this alga.