While lobsters typically walk, they exhibit rapid backward swimming. This unique form of locomotion is a highly effective survival tactic, allowing them to respond to threats.
The Tail-Flip Mechanism
Backward swimming is powered by the “caridoid escape reaction” or “tail-flipping.” This relies on rapid contraction of the lobster’s strong abdominal muscles. The abdomen, or tail, has six unfused segments, providing flexibility for this movement.
When threatened, the lobster swiftly bends its tail underneath its body. This action expels a jet of water, which generates a significant thrust that propels the lobster backward with surprising force. At the end of the tail, a fan-like structure composed of the telson and uropods expands, acting like a paddle or rudder to maximize propulsion and provide some directional control during the escape. This allows for an immediate burst of speed, with reported speeds reaching up to 5 meters per second.
Why Lobsters Swim Backwards
Backward swimming is primarily a defensive and escape maneuver for lobsters. It serves as a rapid response to perceived danger, enabling them to quickly evade predators such as ground fish, eels, and even other lobsters. This sudden burst of movement is considered a biological “eject button” for emergency situations.
The orientation of backward swimming also provides an advantage during an escape. By retreating tail-first, the lobster can keep its formidable claws facing the potential threat, allowing for continued defense while simultaneously moving away from danger. This innate escape behavior is a testament to the efficiency of the tail-flip as a survival strategy in their often hazardous marine habitat. The speed and efficiency of this method are crucial for sudden bursts of movement away from immediate threats.
Other Ways Lobsters Move
While backward swimming is a specialized high-speed escape mechanism, it is not a lobster’s primary mode of everyday travel. Lobsters typically move by walking or crawling along the seafloor. They use their ten legs, specifically the pereiopods, to navigate their environment. Lobsters can walk forward, backward, and even sideways, adapting to the varied terrain of the ocean floor.
When not facing immediate threats, walking is their main method of transportation. Additionally, lobsters possess smaller appendages called pleopods, or swimmerets, located on the underside of their abdomen. These swimmerets can be used for more sustained, albeit slower, swimming or to assist their walking legs in forward propulsion for short distances.