Centipedes, known for their many legs, exhibit a significant range in size across different species. These predatory, segmented arthropods have one pair of legs per body segment and venomous claws behind their head, which they use to paralyze prey. While the name “centipede” suggests a hundred feet, the actual number of legs varies greatly, always in an odd number of pairs. Their size differences are influenced by various factors, including their specific species and the environments they inhabit.
Average Centipede Dimensions
Common centipede species typically measure 1 to 2 inches (2.5 to 5 cm) in length. For instance, the common house centipede (Scutigera coleoptrata), found across North America, measures 1 to 1.5 inches (2.5-3.8 cm) long. These house centipedes have a yellowish-gray body with three dark stripes and long, slender legs and antennae that can make them appear larger than their actual body length.
Garden varieties, such as the brown centipede (Lithobius forficatus), often seen under rocks and in leaf litter, are around 1 inch (2.5 cm) long. Soil centipedes (Geophilomorpha) are small, often less than an inch, though some can reach up to 2 inches (5 cm). These common centipedes are primarily nocturnal predators that feed on smaller invertebrates, making them beneficial in controlling pest populations.
The World’s Largest Centipedes
Some centipede species stand out for their size, far exceeding common varieties. The Amazonian giant centipede (Scolopendra gigantea) holds the record as the largest known species, reaching over 12 inches (30 cm). These creatures are native to tropical and subtropical forests in northern South America and the Caribbean, including countries like Colombia, Venezuela, and various islands. Their diet reflects their size, as they are carnivores that prey on various animals, including large insects, spiders, amphibians, lizards, mice, and even bats.
Other large species include Darwin’s Goliath Centipede (Scolopendra galapagoensis), which can grow up to 11 inches (28 cm) long, and the Chinese Red-Headed Centipede (Scolopendra subspinipes), around 8 inches (20 cm). The Giant Desert Centipede (Scolopendra heros), found in the southwestern United States and Mexico, can also reach lengths of 6.5 to 8 inches (16.5 to 20 cm). These larger centipedes belong to the genus Scolopendra.
Factors Behind Centipede Size
Centipede size varies due to biological and environmental influences. Genetic factors play a role, as each species has a maximum size it can attain. For instance, some species are genetically predisposed to be much larger than others, like the Amazonian giant centipede compared to a house centipede.
Environmental conditions impact how close an individual centipede gets to its species’ maximum size. Centipedes lack a waxy coating on their exoskeleton, making them susceptible to water loss. Consequently, they thrive in moist, humid environments such as leaf litter, under rocks and logs, or in damp basements. Abundant food availability also contributes to larger growth, as centipedes are predators that require sufficient prey to fuel their development. Their growth occurs through molting, where they shed their hard exoskeleton to increase in size, with some species gaining additional body segments and legs with each molt until adulthood.