How many legs does a centipede have?
You might think that centipedes have a hundred legs. But many species of centipedes don't have quite that many legs! The common house centipide has only 15 pairs of legs.
Centipededs and Millipedes
Centipedes and millipedes belong to the subphylum Myriapoda, which contains 13,000 species. They all live on land. They are divided among four classes: (1) Chilopoda (centipedes), (2) Diplopoda (millipedes), (3) Symphyla (symphylans), and (4) Pauropoda (pauropods). They range from having over 750 legs to having fewer than ten legs. They have a single pair of antennae and simple eyes.
Myriapoda are mostly found in moist forests, where they help to break down decaying plant material. A few live in grasslands, semi-arid habitats, or even deserts. The majority are herbivores, but centipedes are nighttime predators. They roam around looking for small animals to bite and eat; their prey includes insects, spiders, and other small invertebrates. If the centipede is large enough, it will even attack small vertebrates, like lizards. Although not generally considered dangerous to humans, many from this group can cause temporary blistering and discoloration of the skin.
Centipedes ( Figure below ) are fast, predatory carnivores, and venomous. There are around 3,300 described species, ranging from one tiny species (less than half an inch in length) to one giant species (the Peruvian giant yellow-leg centipede or Amazonian giant centipede), which may grow larger than 12 inches. This giant centipede has been known to attack, kill and eat much larger animals, including tarantulas. Centipedes have one pair of legs per body segment, with the first pair of legs behind the head modified into a pair of fangs containing a poison gland. Many centipedes also guard their eggs and young by curling around them.
Most millipedes are slower than centipedes and feed on leaf litter and loose organic material. They can be distinguished from centipedes by looking at the number of legs per body segment. Millipedes have two pairs of legs per body segment, while centipedes have a single pair of legs per body segment. Millipedes protect their eggs from predators in a nest of hard soil. Millipedes are not poisonous. They lack the pair of fangs containing a poison gland that centipedes have.
The third class, Symphyla, contains 200 species. Symphylans resemble centipedes but are smaller and translucent. These arthropods have an elongated body, with three pairs of thoracic and about nine pairs of abdominal legs. Many spend their lives in the soil, but some live in trees.
The pauropods are typically 0.5-2.0 mm long and live on all continents except Antarctica. They are usually found in soil, leaf litter, or other moist places. They feed on fungi and decaying organic matter. Adult pauropods have 11 or 12 body segments and 9-11 pairs of legs. They also possess unique forked antennae and a distinctive pattern of movement characterized by rapid burst of movement and frequent abrupt changes in direction. Over 700 species have been described, and they are believed to be closely related to millipedes.
- centipede : Predatory arthropod with one pair of legs per segment.
- millipede : Slow-moving arthropod that has two pairs of legs per segment.
- pauropod : Arthropod resembling centipedes that feeds on fungi and decaying matter.
- symphylan : Arthropod that resembles centipedes but is smaller and translucent.
- Myriapoda are usually found in moist forests, where they break down decaying plant material.
- Millipedes have two pairs of legs per body segment, while centipedes have a single pair of legs per body segment.
Use the resources below to answer the questions that follow.
- Where do centipedes live?
- How do centipedes eat?
- What is the diet of most millipedes? How does this compare to the diet of most centipedes?
- In what kind of habitats are millipedes found? Why are such habitats good places to look for animals which may be similar to the first Arthropods to venture on to land? Be as complete as you can in your answer.
- Arthropod Animation: Millipede Breathing Tubes at http://vimeo.com/37410640
- How do millipedes draw air into their body?
- How does the respiratory system of a millipede differ from the respiratory system of a mammal? Be as specific as possible.
- Where do centipedes and millipedes generally live?
- List two ways centipedes are different from millipedes.