Many people wonder how many legs a centipede truly has, often assuming the answer is exactly one hundred due to its name. The actual number of legs on a centipede varies considerably among different species, making their leg count a fascinating aspect of their biology.
The Truth About Centipede Legs
Centipedes do not possess exactly 100 legs. The number of legs they have depends on the species, with a range from 15 pairs to as many as 191 pairs. This translates to a total leg count between 30 and 382 legs. Each body segment of a centipede typically bears a single pair of legs. Interestingly, the total number of leg pairs a centipede has is always an odd number, meaning a centipede can never have exactly 100 legs.
Different centipede groups exhibit varying leg counts. For instance, species within the orders Lithobiomorpha and Scutigeromorpha commonly have 15 pairs of legs. In contrast, some elongated species in the Geophilomorpha order can have up to 191 pairs of legs, resulting in a much higher total. The number of segments and legs can also change as a centipede develops, with some species hatching with fewer legs and gaining more through molting.
Why the Name “Centipede”
The name “centipede” originates from Latin, combining “centi,” meaning “hundred,” and “pes,” meaning “foot.” While descriptive of their multi-legged appearance, this naming convention has led to a common misunderstanding. The “centi-” prefix here conveys “many” or “numerous” rather than an exact quantity, as no known centipede species has precisely one hundred legs.
Centipedes Compared to Millipedes
Centipedes are often confused with millipedes, but they have distinct differences. Centipedes have one pair of legs per body segment, while millipedes typically have two pairs on most segments. This makes millipedes appear denser with a more rounded, cylindrical body, while centipedes tend to be flatter.
Beyond leg count, their diets and movements also differ. Centipedes are predators, using their speed and venomous claws to capture insects and other small prey. They are known for their fast, agile movements. Millipedes, conversely, are primarily detritivores, feeding on decaying organic matter and moving much more slowly with a wave-like motion. When threatened, centipedes may bite, while millipedes often curl into a tight coil as a defense mechanism.