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How do eels propel themselves through water?
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Locomotion
These birds largely reside in coastal areas of North America, although some populations live in the continent's interior along large rivers.
Eels propel themselves through water using a specialized form of movement known as anguilliform locomotion. Because their bodies are flexible along their entire length, eels generate propulsive thrust by moving in a series of sinuous, wave-like motions that pass from their head to their tail.1
This process involves the following mechanics:
- Muscular Coordination: The undulatory waves are created by metachronal contraction waves that alternate between the right and left axial musculature.1
- Wave Dynamics: During steady swimming, several contraction waves move backward along the body axis simultaneously. As these waves travel toward the tail, their speed and amplitude increase, which generates the greatest propulsive thrust in the caudal (tail) region.1
- Oscillation: Each segment of the eel's body oscillates laterally across the axis of movement, describing a figure-eight loop. While the tail region provides significant thrust, all undulating body segments contribute to the overall movement, with each segment achieving its greatest thrust as it crosses the locomotor axis at its highest speed and inclination.1
This method of axial locomotion allows the eel to effectively overcome the drag and inertia of its aquatic environment.12