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Centipedes and millipedes, along with pauropods and symphyla, are groups of myriapods. In turn, myriapods are a subphylum of arthropods, the most numerous phylum in the animal kingdom, which is also made up of insects, arachnids, and crustaceans. They are very ancient animals: centipede fossils have been found dating back 418 million years.
Centipedes are the class Chilopoda (from the Greek cheilos , meaning lip, and poda , meaning foot), which consists of more than 3,000 species. The number of legs in centipedes varies between 30 and 354. Interestingly, centipedes always have an odd number of pairs of legs, so there is no species of centipede that has a hundred, as its generic name would indicate.
Millipedes are of the class Diplodopa (from the Greek words diplos , meaning double, and poda , meaning foot), with about 12,000 species. Despite its name, no known species has a thousand legs; the record is held by the species Illacme plenipes , with 375 pairs, that is, only 750 legs.
Both centipedes and millipedes have a body consisting of the head and a long trunk made up of many segments and many pairs of legs. Centipedes have one pair of legs on each trunk segment, while millipedes have two pairs of legs on each trunk segment.
differences and similarities
Centipedes are usually predators (they feed on other animals), while millipedes are usually detritus eaters (they feed on decaying organic matter).
Centipedes have strong jaws, and the first pair of legs has claws that they use to catch their prey. These nails can also have glands that inoculate venom. Their prey is very diverse, including insects, spiders , and worms.
Millipedes move more slowly than centipedes. They feed on leaves and other decaying plants; there are only a few species of millipedes that are predatory.
Centipedes have long antennae and their legs extend out from their trunk, while millipedes have short antennae and their legs line under their body.
The rapid movements of centipedes and their venom allow them to escape from their predators and at the same time catch their prey. The defense mechanisms of millipedes are their ability to curl up to protect their weak parts, their ability to dig and bury themselves; many species can also eject a liquid with a very bad smell and taste that scares off their predators.
Both centipedes and millipedes are found throughout the world, but they are more abundant in tropical regions. They require a humid environment for their development and are more active at night.
Examples Chilopoda and Diplodopa
An example of a beautifully colored centipede species is the Sonoran giant centipede, Scolopendra heros , native to Texas, in the United States. It can reach 15 centimeters in length and has very strong jaws. Its venom can cause severe pain and swelling and can be dangerous to children and individuals sensitive to its toxins.
An example of a millipede species is the giant African millipede, Archispirostreptus gigas , which is one of the largest millipedes known, reaching up to 40 centimeters in length with 256 legs. This species is native to Africa, its preferred habitat is forests and it is rarely found at high altitudes. It is harmless and often kept as pets. Giant millipedes have a life expectancy of up to seven years.
Sources
Brusca, RC, Brusca, GJ Invertebrates . Second edition. McGraw-Hill-Interamericana, Madrid, 2005.
Edgecombe, GD, Giribet, G. Myriapod phylogeny and the relationships of Chilopoda . 143-168. In: Llorente Bousquets, J. & Morrone, JJ (eds.): Biodiversity, Taxonomy and Biogeography of Arthropods from Mexico: Towards a Synthesis of Knowledge. Volume III. Science Presses, National Autonomous University of Mexico, Mexico, 2002.
Shear, WA, Edgecombe, GD The geological record and phylogeny of the Myriapoda . Arthropod Structure & Development , 39 : 174–190, 2010.
