Giant African Millipede: Facts, Size, Legs and Diet

What is a giant African millipede?

Millipedes are not insects. They belong to the class Diplopoda, a group of arthropods with about 12,000 described species, and are close cousins of centipedes within the many-legged myriapods. The name Diplopoda means “double feet” and refers to the two pairs of legs carried on most body segments.

Archispirostreptus gigas belongs to the order Spirostreptida, a group of large, cylindrical millipedes common in Africa and the tropics. In southern and eastern Africa big millipedes like this one are widely known as “shongololo” or “chongololo”, names taken from local languages.

The species was first described in 1855 by the German zoologist Wilhelm Peters, originally under the genus Spirostreptus. Several other names given to it in the 19th and 20th centuries are now treated as synonyms.

Appearance

The giant African millipede has a long, rounded body made of many hard rings. Each ring is reinforced with calcium salts, which makes the exoskeleton tough and shiny. The color is usually a deep chocolate brown to almost black, sometimes with slightly paler bands where the rings overlap.

The head carries a pair of short, elbowed antennae that constantly tap the ground, and two patches of simple eyes. These eyes detect little more than light and dark, so the millipede finds its way mainly by touch and smell through the antennae.

Under the body, rows of short legs move in waves from back to front. Watching a giant millipede walk, you can see these waves ripple along its length, a slow but powerful gait that lets it push through leaf litter and loose soil. Along the sides of the rings are tiny pores called ozopores, the openings of its defensive glands.

How big is the giant African millipede?

This species is the longest living millipede on record. Many adults exceed 20 cm (8 in), and the largest reliably measured specimens reach about 33.5 cm (13.2 in), with a body circumference of up to about 67 mm (2.6 in). That is roughly the length of a ruler and as thick as a thumb.

For comparison, most millipedes are far smaller. Common garden species in Europe and North America are usually 1–5 cm (0.4–2 in) long, and the smallest bristle millipedes measure only a few millimeters.

Weights for wild adults are rarely published, so figures quoted online vary widely and are best treated with caution.

How many legs does it have?

A giant African millipede usually has around 250 or more legs, but there is no fixed number. Like other millipedes, it grows by molting and adds new body rings, and new pairs of legs, as it ages. Individuals with more segments have more legs.

The pattern is the same as in most millipedes: the first ring behind the head, called the collum, has no legs; the next three rings carry one pair each; and most of the remaining rings carry two pairs. No millipede of this species comes close to a thousand legs. That record belongs to a tiny, eyeless Australian species, explained in How many legs does a millipede have?.

Habitat and range

The giant African millipede lives in lowland parts of East Africa, from Mozambique north to Kenya, and is also native to southern Arabia, especially the Dhofar region. It rarely occurs above about 1,000 m (3,300 ft).

It is mainly a forest animal, living among leaf litter, rotting logs and loose soil, but it also turns up in wooded coastal areas as long as there are at least some trees. Like all millipedes it loses water easily, because it cannot close its breathing holes and lacks a thick waxy coating, so it stays in damp, sheltered spots by day. Activity rises after rain, when the animals come out to feed and look for mates.

What does the giant African millipede eat?

The giant African millipede is a detritivore: it eats dead and decaying plant material rather than hunting. Its diet includes:

• Fallen leaves that have started to rot
• Soft, decaying wood
• Fallen fruit and other plant debris
• Fungi and microbes growing on this material

Its strong mandibles grind food into small fragments. As the food passes through the gut, part of it is digested and the rest comes out as pellets packed with fungi and bacteria, which speed up decomposition in the soil. In this way the millipede helps recycle nutrients from dead leaves back into the forest floor. The broader story of how millipedes feed is covered in What do millipedes eat?.

Behavior and defense

Giant African millipedes are slow, gentle animals that live mostly alone and are most active at night or in humid weather. They cannot run, bite or sting, so they rely on two lines of defense.

The first is curling. When touched, the millipede rolls into a tight flat spiral with its head in the center and its soft legs tucked inside, leaving only the hard outer rings exposed.

The second is chemical. Glands along the sides release a yellowish to brownish fluid that contains benzoquinones, including toluquinone and 2-methoxy-3-methylbenzoquinone. These compounds smell sharp, repel small predators and can stain human skin brown. They are irritating and can be harmful if they reach the eyes or mouth. This defense is effective enough that the species is reported to be one of the few invertebrates that driver ants cannot overpower. Read more in Are millipedes poisonous?.

The hitchhiking mites

Giant millipedes often carry small, pale mites that crawl over the body rings and between the legs. They are commonly described as cleaners that feed on debris on the millipede’s surface. Scientists consider most mites on millipedes to be harmless passengers, using their host for shelter and transport rather than feeding on it, and they do not appear to harm healthy millipedes.

Reproduction, life cycle and lifespan

Male millipedes transfer sperm with special modified legs called gonopods, located on the seventh body ring. During mating the male and female coil around each other, belly to belly, sometimes for a long time.

The female lays her eggs in the soil or in decaying plant matter. Young millipedes hatch with only three pairs of legs and a few body rings. Each time they molt they add more rings and legs, a way of growing called anamorphosis. Millipedes often molt in a sheltered chamber in the soil and many species eat their old exoskeleton afterward, recovering some of the calcium it contains. It takes several years of molting for a giant African millipede to reach full size.

Giant African millipedes are long-lived for invertebrates. The figure usually given is about 7–10 years, based mostly on animals in zoos and private collections. How long they live in the wild, where they face predators, dry spells and disease, is not well documented.

Predators and threats

Few animals are willing to eat a large millipede that tastes and smells of quinones. Across Africa, millipedes in general are eaten by some birds, mammals and specialist invertebrates. Mammals such as meerkats are known to roll millipedes on the ground to wipe off the secretions before eating them, and a group of assassin bugs called Ectrichodiinae specializes in hunting millipedes.

For the species as a whole there are no major known threats. It is widespread in lowland East Africa, and habitat loss affects local populations more than the species overall.

Conservation status

The giant African millipede is listed as Least Concern on the IUCN Red List (assessed in 2021). It has a large range and remains common in suitable habitat.

The species is also seen in the exotic pet trade. Because many millipedes can damage crops or carry hitchhiking organisms, the United States requires permits to import giant African millipedes, and live specimens may not be brought in casually.

Myths and facts

Myth: millipedes have a thousand legs. The name comes from Latin for “thousand feet”, but the giant African millipede has roughly 250 or more, and most millipede species have far fewer. Only one species is known to exceed 1,000.

Myth: giant millipedes are venomous. Millipedes have no fangs or venom. Their defensive fluid is a chemical deterrent released through the skin, not injected, which is one of the main differences from centipedes. See centipede vs millipede for a full side-by-side comparison.

Fact: millipedes are among the oldest land animals. Fossil millipedes date back more than 420 million years to the Silurian period, and an extinct relative, Arthropleura, grew to over 2 m (6.5 ft) long, far bigger than any living species.