Millipede unbelievable facts||THE APPU WORLD
MILLIPEDE
Hey guys welcome back today let's learn about millipedes yes
But before here's one link of my youtube videos
Let's learn the facts
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name being derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a ball. Although the name "millipede" derives from the Latin for "thousand feet", no known species has 1,000; the record of 750 legs belongs to Illacme plenipes. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures.
Most millipedes are slow-moving detritivores, eating decaying leaves and other dead plant matter. Some eat fungi or suck plant fluids, and a small minority are predatory. Millipedes are generally harmless to humans, although some can become household or garden pests. Millipedes can be unwanted especially in greenhouses where they can cause severe damage to emergent seedlings. Most millipedes defend themselves with a variety of chemicals secreted from pores along the body, although the tiny bristle millipedes are covered with tufts of detachable bristles. Its primary defence mechanism is to curl into a tight coil, thereby protecting its legs and other vital delicate areas on the body behind a hard exoskeleton. Reproduction in most species is carried out by modified male legs called gonopods, which transfer packets of sperm to females.
The history of scientific millipede classification began with Carl Linnaeus, who in his 10th edition of Systema Naturae, 1758, named seven species of Julus as "Insecta Aptera" (wingless insects). In 1802, the French zoologist Pierre André Latreille proposed the name Chilognatha as the first group of what are now the Diplopoda, and in 1840 the German naturalist Johann Friedrich von Brandt produced the first detailed classification. The name Diplopoda itself was coined in 1844 by the French zoologist Henri Marie Ducrotay de Blainville. From 1890 to 1940, millipede taxonomy was driven by relatively few researchers at any given time, with major contributions by Carl Attems, Karl Wilhelm Verhoeff and Ralph Vary Chamberlin, who each described over 1,000 species, as well as Orator F. Cook, Filippo Silvestri, R. I. Pocock, and Henry W. Brölemann. This was a period when the science of diplopodology flourished: rates of species descriptions were on average the highest in history, sometimes exceeding 300 per year
The head of a millipede is typically rounded above and flattened below and bears a pair of large mandibles in front of a plate-like structure called a gnathochilarium ("jaw lip") The head contains a single pair of antennae with seven or eight segments and a group of sensory cones at the tip. Many orders also possess a pair of sensory organs known as the Tömösváry organs, shaped as small oval rings posterior and lateral to the base of the antennae. Their function is unknown, but they also occur in some centipedes, and are possibly used to measure humidity or light levels in the surrounding environment.
Millipede eyes consist of several simple flat-lensed ocelli arranged in a group or patch on each side of the head. These patches are also called ocular fields or ocellaria. Many species of millipedes, including the entire orders Polydesmida, Siphoniulida, Glomeridesmida, Siphonophorida and Platydesmida, and cave-dwelling millipedes such as Causeyella and Trichopetalum, had ancestors that could see but have subsequently lost their eyes and are blind.
Millipede bodies may be flattened or cylindrical, and are composed of numerous metameric segments, each with an exoskeleton consisting of four chitinous plates: a single plate above (the tergite), one at each side (pleurites), and a plate on the underside (sternite) where the legs attach. In many millipedes, such as Merocheta and Juliformia, these plates are fused to varying degrees, sometimes forming a single cylindrical ring. The plates are typically hard, being impregnated with calcium salts. Because they can't close their permanently open spiracles and most species lack a waxy cuticle, millipedes are susceptible to water loss and with a few exceptions must spend most of their time in moist or humid environments.
The first segment behind the head is legless and known as a collum (from the Latin for neck or collar). The second, third, and fourth body segments bear a single pair of legs each and are known as "haplosegments" (the three haplosegments are sometimes referred to as a "thorax). The remaining segments, from the fifth to the posterior, are properly known as diplosegments or double segments, formed by the fusion of two embryonic segments. Each diplosegment bears two pairs of legs, rather than just one as in centipedes. In some millipedes, the last few segments may be legless. The terms "segment" or "body ring" are often used interchangeably to refer to both haplo- and diplosegments. The final segment is known as the telson and consists of a legless preanal ring, a pair of anal valves (closeable plates around the anus), and a small scale below the anus.
Millipedes in several orders have keel-like extensions of the body-wall known as paranota, which can vary widely in shape, size, and texture; modifications include lobes, papillae, ridges, crests, spines and notches. Paranota may allow millipedes to wedge more securely into crevices, protect the legs, or make the millipede more difficult for predators to swallow.
The legs are composed of seven segments, and attach on the underside of the body. The legs of an individual are generally rather similar to each other, although often longer in males than females, and males of some species may have a reduced or enlarged first pair of legs. The most conspicuous leg modifications are involved in reproduction, discussed below. Despite the common name, no millipede has been discovered with 1,000 legs: common species have between 34 and 400 legs, and the record is held by Illacme plenipes, with individuals possessing up to 750 legs – more than any other creature on Earth.
Millipedes occur on all continents except Antarctica, and occupy almost all terrestrial habitats, ranging as far north as the Arctic Circle in Iceland, Norway, and Central Russia, and as far south as Santa Cruz Province, Argentina. Typically forest floor dwellers, they live in leaf litter, dead wood, or soil, with a preference for humid conditions. In temperate zones, millipedes are most abundant in moist deciduous forests, and may reach densities of over 1,000 individuals per square metre. Other habitats include coniferous forests, caves, and alpine ecosystems. Deserticolous millipedes, species evolved to live in the desert, like Orthoporus ornatus, may show adaptations like a waxy epicuticle and the ability of water uptake from unsaturated air. Some species can survive freshwater floods and live submerged underwater for up to 11 months. A few species occur near the seashore and can survive in somewhat salty conditions.
Most millipedes are detritivores and feed on decomposing vegetation, feces, or organic matter mixed with soil. They often play important roles in the breakdown and decomposition of plant litter: estimates of consumption rates for individual species range from 1 to 11 percent of all leaf litter, depending on species and region, and collectively millipedes may consume nearly all the leaf litter in a region. The leaf litter is fragmented in the millipede gut and excreted as pellets of leaf fragments, algae, fungi, and bacteria, which facilitates decomposition by the microorganisms. Where earthworm populations are low in tropical forests, millipedes play an important role in facilitating microbial decomposition of the leaf litter. Some millipedes are herbivorous, feeding on living plants, and some species can become serious pests of crops. Millipedes in the order Polyxenida graze algae from bark, and Platydesmida feed on fungi. A few species are omnivorous or in Callipodida and Chordeumatida occasionally carnivorous, feeding on insects, centipedes, earthworms, or snails. Some species have piercing mouth parts that allow them to suck up plant juices.
Comments
Post a Comment