Lobsters move backward only as a specialized, short-burst maneuver, not as their typical method of travel. This rapid backward movement is an instinctive, reflexive action reserved for escaping a sudden threat. When not in danger, a lobster’s daily life involves a much slower, more deliberate form of locomotion along the ocean floor.
Daily Movement on the Seabed
A lobster’s primary mode of travel is walking, accomplished using its ten jointed legs, known as pereiopods. These appendages, including the large, claw-bearing first three pairs, are instrumental for navigating the seabed. This walking is a slow, methodical process, allowing the lobster to forage for food and explore its immediate environment. The movement is generally forward or slightly lateral, providing directional control as it searches the bottom substrate. The walking legs are equipped with sensory hairs, allowing the animal to taste and smell the environment as it moves, aiding in the search for buried prey or suitable shelter.
The Mechanism of Backward Escape
The impressive backward surge is scientifically termed the caridoid escape reaction, or “tail-flipping.” This maneuver is triggered by a sudden stimulus indicating immediate danger. The reaction is an innate, high-speed response that is nearly involuntary.
Propulsion is generated by the powerful, rapid flexion of the lobster’s muscular abdomen, commonly called the tail. Specialized giant interneurons coordinate this sequence with extreme speed, causing the rapid contraction to slam the abdomen forward against the body, creating a powerful thrust of water. The broad, paddle-like tail fan, composed of the telson and uropods, maximizes the force generated. This action propels the animal backward and slightly upward, away from the threat. This tail-flip can achieve speeds up to 5 meters per second (over 11 miles per hour) in a single burst.
Controlled Movement in Water
Beyond walking and rapid escape, lobsters possess another mechanism for controlled movement in the water column. This is accomplished using the small, feathery appendages located on the underside of the abdomen, known as pleopods or swimmerets. These structures are too delicate to contribute to the tail-flip, but they are used for gentle, sustained propulsion.
The swimmerets beat rhythmically in a coordinated, wave-like pattern, allowing the lobster to hover, maintain position, or move slowly forward or backward. This slow swimming is particularly utilized by females, who use the continuous water movement to aerate the clusters of eggs they carry attached to these appendages.