The question of what creature possesses the most legs often leads to the subphylum Myriapoda, a group of arthropods that includes millipedes and centipedes. These creatures are not insects but distinct classes of animals recognized by their elongated bodies and numerous appendages. Millipedes and centipedes are frequently confused but represent vastly different evolutionary paths. This exploration focuses on the biological realities of these segmented organisms, confirming that millipedes (Class Diplopoda) are the true record-holders.
The Creature with the Most Legs
The name “millipede,” derived from the Latin for “a thousand feet,” was an exaggeration until recently. The title of the world’s leggiest animal belongs to the millipede species Eumillipes persephone, a pale, eyeless creature found deep underground in Western Australia. One female specimen was found to have an astonishing 1,306 legs, shattering the previous record of 750 legs. This high leg count is rooted in the millipede’s defining characteristic: diplosegmentation, where nearly every visible body segment is actually two fused segments. This results in two pairs of legs per segment, providing the necessary traction to push their long bodies through small gaps and fractures in the soil.
Understanding Centipedes
Centipedes (Class Chilopoda) are the other major group in the Myriapoda subphylum. They are often mistakenly believed to be the leggiest due to their rapid, visible movement, but they only have one pair of legs per body segment. Even the centipede species with the most legs, such as the genus Gonibregmatus, only reach a maximum of 382 appendages. Unlike the slow-moving millipedes, centipedes are active, agile predators that rely on speed to hunt. They subdue prey using specialized venomous appendages called forcipules or maxillipeds, which are pincer-like structures located behind the head that inject venom.
How to Tell Them Apart
Distinguishing between centipedes and millipedes involves observing a few distinct physical and behavioral characteristics. Millipedes typically have a rounded, cylindrical body, while centipedes possess a flatter, dorsoventrally compressed body. The two groups also move very differently, which is the easiest field identification method. Millipedes move slowly with a smooth, wave-like motion as they burrow, and when threatened, they curl into a tight coil or release a defensive secretion. Centipedes are known for their fast, darting movements as they pursue prey, and they will use their speed or attempt to bite with their venomous forcipules when threatened.