Mantis shrimp are often mistaken for true shrimp due to their misleading name and appearance, which blends characteristics of a praying mantis with a generalized shrimp-like body. However, these vibrant marine creatures are distinctly different from the shrimp commonly found on dinner plates.
Beyond the Name: Their True Identity
Mantis shrimp are not true shrimp; they belong to a completely separate scientific order called Stomatopoda. True shrimp, along with lobsters and crabs, are classified under the order Decapoda. This taxonomic distinction highlights a significant evolutionary divergence. Stomatopods separated from other malacostracan crustaceans, a class that includes true shrimp, approximately 400 million years ago.
While both mantis shrimp and true shrimp are crustaceans, their anatomical blueprints differ considerably. Mantis shrimp possess highly specialized raptorial forelimbs that are unique to their order, unlike the walking legs or grasping claws found in decapods. These differences extend to other aspects of their body plan, underscoring their distinct biological identity.
Unparalleled Abilities
Mantis shrimp are known for their powerful and swift strike. These animals are categorized into two main groups based on their predatory appendages: “smashers” and “spearers”. Smashers wield club-like forelimbs capable of delivering an incredibly forceful blow, while spearers possess barbed, spiny appendages designed to impale soft-bodied prey. Their strikes are among the fastest movements in the animal kingdom, reaching speeds up to 23 meters per second underwater, generating forces exceeding 1500 Newtons.
This remarkable force is amplified by a phenomenon called cavitation. As the mantis shrimp’s appendage moves through water at extreme speeds, it creates rapidly expanding and collapsing bubbles, known as cavitation bubbles. The implosion of these bubbles generates a secondary shockwave, adding significant power to the initial impact, a “one-two punch” capable of fracturing hard shells.
Beyond their striking power, mantis shrimp also possess an exceptionally complex visual system. Their stalked eyes can move independently, allowing them to scan their environment with impressive flexibility. Mantis shrimp eyes contain up to 16 different types of photoreceptors. This allows them to perceive a broad spectrum of light, including ultraviolet light. They are also unique in their ability to detect polarized light. This advanced vision assists them in identifying camouflaged prey and is thought to be used for complex communication through patterns of polarized light on their bodies.
A Case of Mistaken Identity
The common name “mantis shrimp” arises from observed resemblances to two distinct animals. The “mantis” part of their name comes from their specialized raptorial forelimbs. These appendages are folded beneath their bodies in a manner strikingly similar to the grasping forelegs of a praying mantis, ready to snap out with incredible speed to capture prey.
The “shrimp” portion of their name is attributed to their elongated body shape and general appearance as a marine crustacean, which bears a superficial resemblance to true shrimp. This naming convention highlights how common names often serve as descriptive labels based on observable traits rather than precise biological classifications. Other common descriptors for these creatures, such as “sea locusts” and “thumb splitters,” also reflect their perceived characteristics or powerful capabilities.