Euglena move in two primary ways: using their flagella and through a unique body contortion called metaboly.
Flagellar Movement
Euglena possess two flagella, although only one is typically visible.
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The Longer Flagellum: This is the primary flagellum used for swimming. It rotates, pulling the Euglena through the water. The flagellum doesn't beat in a simple back-and-forth motion, but rather in a helical pattern, creating a propeller-like force.
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The Shorter Flagellum: This flagellum is typically non-emergent or very short and may play a role in sensing the environment.
Metaboly (Euglenoid Movement)
Euglena also move by changing their body shape, a process called metaboly or euglenoid movement. This is possible because Euglena lack a rigid cell wall; instead, they have a flexible proteinaceous layer called the pellicle.
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Mechanism: Metaboly involves a series of wave-like contractions and expansions of the body, allowing the Euglena to squeeze through tight spaces or move along surfaces. This movement is driven by contractile proteins located beneath the pellicle.
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Observation: Metaboly is particularly noticeable when Euglena are on solid surfaces or in viscous environments where flagellar propulsion is less effective.
In summary, Euglena use their rotating flagellum for swimming and metaboly (euglenoid movement) for crawling or maneuvering in restrictive spaces.
