Many people wonder if millipedes truly have 1,000 legs, given their common name. Despite this widespread belief, most millipedes do not possess a thousand legs. This article clarifies their actual leg count, explores the name’s origin, and distinguishes them from centipedes.
Actual Leg Count
The number of legs on a millipede varies by species. Most millipede species have fewer than 100 legs, with counts generally ranging from 24 to 750. For example, some species can have around 400 legs, while smaller species like the flat-backed millipede (Polydesmus angustus) might only have about 40.
A remarkable exception is Eumillipes persephone, a species discovered in Western Australia in 2020. This millipede holds the record for the most legs of any known animal, with some individuals possessing up to 1,306 legs. Found 60 meters underground, this subterranean species is the first millipede recorded to have over a thousand legs.
Why They Are Called Millipedes
The name “millipede” originates from Latin, where “mille” means “thousand” and “pes” means “foot.” The name was likely given due to the impression created by their many body segments, each bearing numerous legs, rather than an accurate count.
This terminology suggests a historical observation of their abundance of legs, leading to an exaggerated, albeit memorable, descriptor. Until the recent discovery of Eumillipes persephone, no millipede was known to truly live up to this “thousand-footed” designation.
Distinguishing Millipedes from Centipedes
Millipedes are often mistaken for centipedes, but they have distinct characteristics. A primary difference is their leg arrangement: millipedes typically have two pairs of legs per body segment, while centipedes have only one pair per segment. This structural difference also influences their body shape; millipedes generally have a more rounded, subcylindrical body, while centipedes are more flattened.
Their diets and movements also differ. Millipedes are primarily detritivores, feeding on decaying organic matter such as leaves, wood, and other plant material, contributing to soil enrichment. Centipedes are carnivores that actively hunt and consume other insects, spiders, and small arthropods, using venom to subdue their prey. Millipedes tend to move slowly and deliberately, often curling into a spiral as a defense mechanism, while centipedes are known for their faster, more agile movements.