Millipede

Giant Madagascar Millipede

"Kurly"
Giant Madagascar Millipede

CLASSIFICATION

Millipedes are elongate arthropods with many body segments and two pairs of legs on most segments. They are circular in cross section and have short antennae. Millipedes usually live in damp places in temperate and tropical regions and feed mainly on decaying plant material. They are slow-moving and harmless to humans, but for protection some give off an ill-smelling and sometimes irritating fluid. Most species are a few centimeters in length, but some tropical millipedes grow to be 30 cm (1 ft) long. Found worldwide, millipedes have segmented bodies with two pairs of legs on each of the 9 to 100 or more abdominal segments, (formed by the fusion of two originally separate segments), and one pair on three of the four thoracic segments. Because of the numerous legs, the animals walk slowly, with a wavelike motion of the legs down the body. In length they range from about 0.2 to 23 cm (about 0.1 to 9 in); the largest North American species, Narceus americanus, is 10 cm (4 in) long. They grow by molting and may live for one to seven years. Millipedes shun light and are very secretive.

Millipedes move by exerting a powerful pushing force, that enables them to push their way through humus, loose soil, and leaves. The force is exerted entirely through legs, with a backward pushing stroke that is activated in waves along the length of the body. Millipedes also use a head-on pushing motion that allows it to burrow in the dirt.

Millipedes are commonly known as "thousand leggers", however they usually only have a few hundred legs. The most number of legs ever counted on a millipede is 752.

RANGE

The Giant Millipede is found throughout the world, especially in the tropics. Our millipede is a Madagascar milllipede, from the island Madagascar off the East coast of Africa.

HABITAT

Millipedes are secretive and usually shun light, by living under stones, leaves, bark, logs, and soil. Its many legs do not make it speedy, and in facts millipedes are slower than centipedes. However, their legs do supply power neede to burrow into the ground, where they eat decaying vegetation.

In order to compensate for their lack of speed when trying to escape from a predator, the millipede has several protective mechanisms. One form of protection, and maybe the most obvious, is the hard exoskeleton. Another form of protection is their ability to curl up into a ball, so that their vulnerable underside is protected , finally as stated before, millipedes can burrow into the gournd for protection.

Many groups of millipedes have what are called "repugnatorial glands". There is usually one pair of glands per segment. Each gland consists of a large secretory sac, which empties into a duct and out through an external pore. The secretion is usually toxic or repellent to other small animals and the secretion of some large tropical species is reportedly caustic to human skin. The fluid is usually expelled slowly, but some large, tropical species can discharge it as a spray for 20 to 30 cm.

DIET

Most millipedes are herbivores, and feed mostly on decomposing vegetation. Their food is usually moistened by secretions and chewed or scraped by the mandibles (jaws). However, in some tropical regions, the millipedes have adapted a long, piercing beak that is used for feeding on plant juices.

A carnivorous or omnivorous diet has been adopted by some rock-inhabiting millipedes. It is said that their prey include phalangids, insects, centipedes, and earthworms. Like earthworms, some millipedes ingest soil from which organic matter is digested.

GESTATION

The genitalia of millipedes are on their 3rd body segment, with males having their 1st pair of legs on their 7th body segment modified into a special pair of claspin organs which are often held close to the body. Males communicate to females their intent and identity in a variety of ways. The signal is tactile in most millipedes, when the male climbs onto the back of the female, clinging by special leg pads. Antennal tapping, head drumming, and stridulating are utilized by various other millipedes. Many millipedes produce a substance called pheromones, that can either imitate mating behavior, or continue the sequence of steps that were initialized by other signals.

A millipedes eggs are fertilized at the moment of laying, and anywhere from 10 to 300 eggs are produced at one time, depending on the species. Some deposit their eggs in clusters of soil or humus. Some species will regurgitate a material that is molded into cup by the head and anterior legs. A single egg is lid in the cup, which is then sealed and polished. The so called capsule is deposited in soil or humus, and is eaten by the young hatchling upon birth.

The eggs of most species hatch in several weeks, and the newly hatched young usually have only the first three pairs of legs, and not more than several trunk rings. With each molt, more and more segments and legs are added to the trunk.

LONGEVITY

Millipedes live from one to ten or more years, depending on the species.

CONSERVATION

In some ecosystems millipedes are more important than worms as agents of soil turn over, and like worms they eat the soil as they burrow through it.

BIBLIOGRAPHY

Barnes, Invertebrate Zoology; 5th Edition, CBS College Publishing, 1987, pp. 674-681.

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