Centipede vs. Millipede (Differences, Comparisons And Facts)

Centipede and millipede although sounds similar are different species. They have a lot in common but are quite different as well. From physical characteristics to the way they move etc.

The word centi comes from the new latin prefix which means hundred. Although they don’t have hundred legs but they have 15-70 of them. The word milli means thousand feet which they don’t have, the highest recorded so far is 750. 

Centipede

Centipedes are predatory arthropods of the Chilopoda class. Though centipedes refer to a hundred legs, they always have odd pairs of legs. Each of their body-parts has one pair of legs. They have a pincer-like appendage on the front, which injects venom into the prey. Centipedes are mostly carnivorous.

Centipedes can be found, from a few millimeters to nearly one foot in length. They usually are red and brown shades and get found almost in all places in the world. Their body lacks the cuticle or the waxy covering, thereby losing water all the time. Thus they require moist areas to habitat.

Evolution

Centipedes belong to the subphylum Myriapoda, which has been in existence from ancient times. The fossil remains indicate their presence to around 400 million years ago. Today they get found everywhere with modification to their structure and behavior. Odd pairs of legs and their forcipule remain unique across all species of centipedes.

Body Structure

Centipedes’ head is either rounded or flattened. They have a pair of an antenna in the front. One pair of long mandibles and two pairs of maxillae form the mouthpart of centipedes. One of these pairs of maxillae forms the lower lip and has short palps.

Their first pair of elongated limbs get known as maxillipeds and end in sharp claws. A tube runs from the venom glands to the edge of these claws. When a centipede holds its prey with these claws, the venom gets automatically injected thro’ the wound.

Eyes:Many species of centipedes do not have eyes. Some have simple eyes or ocelli. Few varieties of centipedes have these ocellis grouped like compound eyes. Centipedes are mostly blind, and those with ocelli only see some lights and shadows.

Forcipules:The first pair of legs in centipedes ends with forcipules or a claw-like structure. This is unique to them among all other arthropods. These forcipules get used to pierce the skin of prey, disable them with the venom injected, and held together for the mouthpart to feed.

Legs:Centipedes have fifteen or more segments. Each segment bears one pair of legs, except for the last few. The first pair of the leg is the maxillipeds, with the forcipules projecting forward and covering its mouth. The legs from the second segment onwards get used in walking, running, and sprinting. Each leg at the back is slightly longer than the one in front. The last leg is almost twice the size of its first pair of the leg.

The legs of centipedes are arranged outwards from their bodies. So when they move, they use all the legs together, without any hindrance. The last segment of their body has the telson and an opening for reproduction.

Digestion:Centipedes have a simple digestive system, with the digestive glands attached to the mouthpart thro’ tube. They excrete thro’ a single pair of Malpighian tubes. Centipedes seek out their predators with the help of their antenna. They breathe thro’ their tracheal system, with pores or spiracles, which is present in each of their body segments.

Reproduction

Reproduction in centipedes does not require copulation. Males leave their spermatophore for the females to find. In some species, the males undertake a courtship dance to attract the females to their sperms.

The female centipede uses the sperm to fertilize their eggs and lays them singly in the soil. They lay around 10 to 50 eggs at a time, covering them with dirt and leaves to hatch. The eggs of centipedes take one to few months to hatch, depending upon the species.

Some female species look after their eggs till they get hatched, licking them periodically and protecting them from fungi. Some stay with their young ones for some time, till they get to become self-sufficient.

Longevity

Some species of centipede attain adulthood and reach reproductive age in one year, while the Scolopendra Coleoptrata may take even three years. On average, centipedes live up to five years, while the larger varieties may live for over ten years.

The young centipede gets hatched with fewer body segments and legs. More segments and legs get added with every molt. Usually, females have more body segments and legs compared to the males. Centipedes have body segments ranging from 15 to 191, which bears a pair of legs. Legs are always in odd multiples, and hence no centipede has a hundred legs.

Generalist Predator

Centipedes are generalist predators. They are nocturnal creatures and preys on all kinds of vertebrates and invertebrates, depending upon their size and proximity to the centipedes’ habitat. They are known to feed on reptiles, amphibians, bats, small mammals, and birds. Centipedes feed on all types of insects like an earthworm, spiders, and other soft-bodied creatures. They feed on vegetation only if there is a shortage of their regular prey.

Prey

Centipedes fall prey to wide varieties of snakes, mongoose, mice, beetles, and birds. Their defense system includes speed, claws, and venom. Some species secrete sticky defensive chemicals, consisting of hydrogen cyanide and benzoic acid. These mechanisms keep some of their predators at bay.

Habitat

Centipedes lose their water rapidly due to the absence of wax from their body surface. They also require water to convert nitrogen to ammonia during their digestion process. Hence, they need moist areas to live in. They get found in marshy land, forests, caves, fields, and gardens. Some species live near the water edge and some inside the water too! Those who live dry arid regions have adapted themselves accordingly.

Uses Of Centipede

As food: In China, large varieties of centipedes get skewered, grilled, or deep-fried. You also see them available in stores. They get considered a delicacy for consumption. In China, Laos, and Cambodia, centipede gets known to have medicinal and rejuvenating properties. They get seen submerged in their liquor, and then this special drink gets consumed on important occasions.

Source of terror:Humans get terrified with the sight of centipedes. With their many legs, darting towards shadows is a sure-shot startling experience for us. The smaller species can hardly pierce the human skin. When the larger varieties sting, it causes soreness, nausea, and fever. With proper care and treatment, you recover since their venom is not fatal. Bite on children and those with sting allergies need to be careful and must resort to proper medical treatment.

Centipede Families

Given below are the various centipede family in existence today:

Scutigeromorpha: These centipedes generally have fifteen pairs of legs. They have ocellis joined together as compound eyes. They move quickly, including crawling across the ceiling. They remain unhurt from a long drop. These get also known as the house centipedes. Their breathing spiracles get found at the back and underside of each of their body segments.

Lithobiomorpha: The centipede of this species get to be known as the stone centipede. They have fifteen body segments, and their compound eyes are missing. Some ocellis are there, and their legs and antennas are shorter. This variety has one pair of spiracles present laterally on each of the body parts.

Craterostigmomorpha: This species of centipedes get found only in New Zealand and Tasmania. They date back to pre-historical times and have fifteen body segments. Their young ones molt only once. These species have sternal pores, from which get secreted a sticky, foul-smelling substance, which repels predators and fungi.

Scolopendromorpha: This is the tropical centipede with 21 or 23 body parts, with similar pairs of legs. Scolopendropsis duplicate has 39 or 41 body segments. Their antenna has around 17 sections, and this family has four fixed ocellis on either side of their head. Mimops genus has only one pair of ocelli, while the rest of the species are blind. The two known amphibious species of centipede belongs to this clan. Scolopendra gigantea gets to be known as Giant Amazonian Centipede. They grow up to one foot in length and live in the rain forests and caves.

Geophilomorpha: This species of centipede get also known as soil centipede. They are all blind and has fourteen segmented antennae. They have 27 and more body segments, which bear legs. This eyeless centipede has spiracles on all leg-bearing body segments. They get extensively found and has upwards of five families of centipedes.

Millipedes

Millipedes are arthropods with two pairs of jointed legs on most body segments and are from class Diplopoda. Most of these creatures have more than 20 body segments, elongated, round or flattened bodies.

Most of these arthropods are slow-moving detritivores, i.e., feeding on decaying leaves and other dead plant parts. Some are known to be predatory. They are harmless to humans, except that they may cause extensive damage in the garden and green-house.

They secrete a variety of chemicals through their body pores, which gets used to defend themselves against predators. The males transfer their sperms through modified legs called gonopods to the females. Some of the pre-historic millipedes grew over six feet in length. Nowadays, they get to develop up to 12 to 15 inches in length. The longest species of millipede is the giant African millipede.

Evolution

Millipedes got found from a very early period of life on earth. Due to better availability of oxygen on our planet, millipedes grew to enormous size, and over the years they have got smaller. In the early days, these millipedes had breathing spiracles, and their pores oozed chemicals to deter their predators.

Body Structure

Millipedes vary in sizes, from 2mm to more than a feet in length. They can have around eleven to over a hundred body-segments. They are generally brown or black. However, some have incandescent hues, which could be toxic. They secrete deadly chemicals to ward of predators.

Their body structures vary widely. There are bristle bodied millipedes, which are soft-bodied. Then you have the hard-bodied, where the exoskeleton gets segmented. You have the shorter and longer versions of these creatures.

Head: The head of a millipede is rounded on top and flat below. They have one pair of antenna with eight segments. In the front, they have the mandibles called the gnathochilarium or jaw lip. They have some ocelli arranged on either side of the head. Some of the extinct millipedes were blind.

Body: The millipede’s shape is either cylindrical or flattened, consisting of numerous metameric segments. Each of these segments gets made of exoskeleton with four chitinous plates – tergite above, pleurites on either side, andsternite at the bottom, where the legs get joined. Their body is hard, made of calcium salts. The millipedes do not have waxy cuticles covering their exoskeleton, leading to a loss in body moisture rapidly. This forces them to remain in a moist environment.

Segments: The first segment behind the head is legless, known as collum. The next three segments have only one pair of legs, and these segments get to be known as haplosegments, which comprises the thorax. From the fifth segment onwards, millipedes have two pairs of legs in each body segments, and these segments get to be known as diplosegments. The last section is the telson with the anal ring, anal valve, and the anus.

Paranota: Millipedes get to have body extensions known as paranota, which vary in size, shape, and texture. This modification gives them various physical structures, which helps them to protect their legs and hide in crevices from their predators.

Legs:Each of the legs of millipedes have around seven segments and are of similar length. The males have a little longer legs compared to females. No millipedes have a hundred legs. The most number of legs get found on Illacme plenipes of 750 number, more than any, present, earth living creature. Generally, millipedes have between 30 to 400 legs.

Internal organs: Millipedes have two pairs of spiracles, located on either side of each segment near the legs. They get connected internally thro’ a pouch to their tracheal system. Their heart runs across their body with aorta on their head. They have a simple digestive system, with a single tube and a pair of salivary glands connected to their mouthparts.

Reproduction

Millipedes differ concerning reproduction between species. The bristle millipede male secretes a web-like substance, where they deposit their spermatophores and gets picked up by females to fertilize her eggs. In all other millipede species, the males have specially developed legs called gonopods. This gets used by the males to transfer the sperm into the females during copulation.

Gonopods:In Pentazonia millipede, this adaptation gets located at the rear of the body known as telepods. This gets also used to grasp the females. In Helmithomorpha, this gonopod gets situated in the seventh body segment. These gonopods vary between species. Some get found close to the body extended forward, while in others, they may get retracted. The gonopods get developed during various molts from a simple leg to this structure, on maturity and reproductive stage.

Cyphopods:The genital openings of millipedes get located on the third body-segment near the underside of the second pair of legs. Males have one or two penes, thro’ which they deposit the sperm on to their gonopods. In females, this opening opens on to a pair of sacs known as cyphopods or vulva. The packet of sperm gets stored in this sac for later fertilization. Millipede sperm lack flagella, which is unique among myriapods.

Copulation:Except for the bristle millipede, other males conduct a ritual to attract the female. Some secrete an edible glandular fluid, some run over the female’s body, while other species might chirp or stridulate. During copulation, males place their seventh segment opposite the third segment of the female.

The gonopods open up the cyphopods of the female, sperm packet get deposited on the gonopods, which gets inserted and collected inside the vulval sacs. The copulation occurs facing each other.

Eggs:Females lay between ten to three hundred eggs at a time, depending upon the species. They lay their eggs on moist soil of decaying leaves. Some create a nest by surrounding the area with dried feces to protect their eggs.

Others wrap their eggs in a cocoon. Most millipede females abandon the eggs once laid, for them to hatch on their own. Some species provide parental care to the eggs and the young hatchlings. When the females lay their eggs, they fertilize them with the stored sperm in their vulval sac.

Young adults:The eggs hatch after a few weeks. The young millipede may have around three pairs of legs and another four body segments. With each molt, they keep adding more body segments and leg pairs. Some molt within their unique nest or silk cocoons. These also get used as shelters from the harsh environment.

Some feed on the molted exoskeleton. The adulthood or reproductive stage gets reached after the final molt. Some species keep molting beyond their adulthood. In some species, they become unreproductive, and their reproducing organs retracts. Depending upon the species, they live between one to ten years!

Habitat

Millipedes survive all types of climatic conditions and get found almost everywhere, other than Antarctica. They are terrestrial and get noticed in all kinds of forests, caves, seashores, and river beds. They adapt to the salty nature along the seashore, locate humid areas in the caves and desert region. In submerged plains, they can survive for nearly a year underwater! Their preferences are moist and wet terrain.

Burrowing

Millipedes adopt three main methods to burrow into their terrain. The burrow, bulldoze, or bore their way inside. Julida, Spirobolida and Spirostreptida species of millipedes, lower their head and barge into the soil surface.  The collum of the exoskeleton lead the way. Polydesmida species with their flat-back insert their head as a wedge on a horizontal surface. Their paranota gets used to push back to open up the opening for the millipede to get through.

Polyzoniida millipede bore thro’ with the help of smaller body segments in front, leading to more significant at the rear. The move forward with their legs, and the wider rear part widens the gap for it to pass through. Some millipede species remain on the surface to forage and predate, depending upon their size and species. Some are too small to burrow, while others can move quickly.

Diet

Millipedes, on the whole, are detritivores. They feed on leaf litter, decaying plants, decomposing vegetation, feces, or organic matter in the soil. They consume large quantities, and their digestive system process this with excreta consisting of pellets of leaf fragments, algae, fungi, and bacteria. These help in the decomposition of soil and make them fertile. In the absence of earthworms in some regions, the millipedes do their role.

Some species of millipedes are herbivores and feed on live plants. Some feed on algae and fungi. While the omnivore and carnivore millipedes feed on insects, earthworms, centipedes, and snails, these species have strong jaws and tearing mouthparts.

Predators

Many species feed on millipedes. Their predators include amphibians, reptiles, mammals, birds, and insects. Coatis and meerkats, roll the dead millipedes on the ground to remove their defensive chemical shield, before devouring them. Some invertebrates like the glowworm beetles, Probolomyrmex ants, chlamydephroid slugs, and dung beetles have got themselves developed to feed on millipedes.

Hundreds of assassin bug species can prey on millipedes. Parasites of millipedes are nematodes, acanthocephalans, phaeomyiid flies. There are more than 30 fungal species that live on them externally.

Defenses

Since they do not have venom, sting and speed, they protect themselves by coiling around tightly when attacked. This allows them to protect their frail legs with their hard exoskeleton exterior. A large number of millipedes get known to excrete foul-smelling and abrasive chemicals thro’ their tiny pores along their body surface, known as ozopores. They secrete phenols, alkaloids, hydrogen cyanide, and benzoquinones. Some are caustic enough to burn the exoskeleton of predators like ants and other insects. It also affects the skin and eyes of larger predators. Lemurs and capuchin monkeys get known to rub these millipedes on their bodies to act as a mosquito repellant. Some of these defensive chemicals also have antifungal properties.

The bristle millipedes lack both – hard exoskeleton and defensive chemicals. Their soft body gets covered by tiny bristles, and in some species, these detach and entangle ants.

Different Types

Given below are some particular kinds of millipedes found:

Giant African millipede:They grow around 15 inches in length and three inches thickness. They have about 250 legs and get considered pets.

Shocking pink dragon millipede:These millipedes warn their predators with their bright color and spines on their body surface. Surprisingly, the sticky substance secreted by them smells of almonds!

Cave millipedes:These millipedes have adapted to the environment. They are pale in color and are blind.

Humans

Millipedes have no impact on humans. They do not help them either ecologically, economically, or socially. Millipedes can’t bite, and their chemicals do not affect humans, except for discoloration of the skin. Some chemical secretions can cause irritation and inflammation. Contact with the eye can lead to conjunctivitis and keratitis. Wash the affected area with water and apply some soothing gel.

Pests: Some species of millipedes get considered household pests. They get to invade gardens, destroy crops, and eat into gardens. Some species exhibit swarm behavior. Some pests get to destroy sugar beets and other root crops. Millipedes get known to infest thatched huts in villages. Some larger varieties of millipedes get kept as pets, while others get traded.

Medicine: Millipedes appear in folklore, get considered in the traditional medical field, while some tribes associate them with rains. In Zambia, millipede pulps get used to treat wounds. In Cameroon, the juice of millipedes gets used for earaches. Dry millipede smoke in the Himalayas, get used to treating hemorrhoids.

Natives in Malaysia use millipede secretion for their poison arrow tip. Sporobolus Bungie millipede secretion gets to inhibit division in cancer cells in humans. One tribe gets to eat dried millipedes with tomato sauce!

Research:Millipedes and their location get used in robotic science. In scientific research, their exoskeleton segments, the function of paranota in boring, walking with multiple legs, get used in various inventions and applications.

What Are The Similarities Between Centipedes And Millipedes?

Group: Both of them belong to the same arthropod group.

Body structure: They have a segmented body and multiple legs.They are both elongated and segmented, with their heads rounded or flat.

Secretion: They secrete chemical compounds that are detrimental to predators.

Antennas: Both have antennas. Their antennas get used to forage and prey. They also get alerted concerning predators.

Spiracles: Spiracles on the sides of body-segments helps them to breathe, which is then distributed thro’ their body using their tracheal system.

Color: Many species have the similar coloration of different shades of red and brown.

Reproduction: Reproduction of centipede and millipede gets done thro’ sexual process.Both of them lay their eggs in the soil.

Moisture loss: Since both of them do not have waxy cuticles on their exoskeleton, they quickly lose body moisture.

Habitat: They both seek moist and damp environment. They dwell inside the soil, in crevices, under foliages, inside caves, and deadwood.

Internal organs: Both have a simple digestive system, running across their entire body.

Size: They both grow up to one foot in length.

Legs: They have one pair of legs on the first three body-segments.

Young ones: Eggs get hatched for both with young ones appearing without any pupal stage. They have less number of body-segments and hence less pair of legs. More body-parts and legs get added with multiple moldings.

Parental care: There are some species among centipedes and millipedes, where females take care of their eggs from fungi attack and their young ones from predators.

Vision: Both of them have a feeble vision. Some might have some ocellis to discern light and shadow. Both depend upon their segmented antenna to feel around.

How Do We Tell Them Apart?

Legs: Centipede has fewer legs compared to millipedes. Centipedes have between 30 to 350 legs, while millipedes can have legs up to 750 numbers. All centipede species have one pair of legs per body segment, while millipedes have two pairs of legs. The legs of centipedes get extended away from their body. Millipedes’ legs are nearer their body. Centipedes’ legs become longer front to back. Legs of millipedes are similar in size right across.

Forcipules: The first pair of legs of centipedes gets developed as a unique appendage, known as forcipules, which ends in claws with venom tips. They use this to hold their prey, pierce the skin and inject venom to paralyze them. Millipedes do not have such a structure.

Spiracles: Centipedes generally have one spiracle per body-segment, while the millipede has two spiracles per body segment. This gets used to taking in oxygen.

Antennas: Antennas of centipedes are more protracted, compared to the millipedes’.

Gonopods: The hind pair of legs on the seventh segment of millipedes have an adaption known as gonopods. They use this pad to open the female vulva sac and deposit their spermatophore. Centipedes do not have any such adaptation.

Diet: Centipedes are predominantly carnivores, while millipedes are generally detrivores. Centipedes eat insects, amphibians, bats, mice, and small birds. They feed on vegetation only if there is a shortage of prey. Millipedes feed on decaying matter in the soil, feces, dead leaves, decomposing plants, and other dead organic matter. Very few species of millipede are a carnivore and eat insects.

Reproduction: Centipede does not copulate for reproduction. The male leaves their sperm packets for the females to store and use later to fertilize her eggs. Millipedes, other than the bristle millipede, have a unique adaptation on their hind legs on their seventh body segment. This is known as gonopods.

During copulation, males position themselves with their seventh segment in-line with the third segment of females, where the vulva gets located. The sperm packets get transferred by the males with the help of their gonopods, into the vulva sacs of females. They face each other during copulation.

Movement: Centipede can move very quickly and also can travel vast distances. Their legs are long, away from the body and hind legs longer than the front. This helps them with a quick movement. Millipedes have more legs than centipedes, but they are tiny, similar size, and inward-facing. Thus, they move very slowly and don’t travel long distances.

Human: You have the house centipede, which dwells in crevices, under the sink, below the broken tiles or in the damp basement — these feed on all types of insects, including spiders. Millipedes do not dwell inside the human habitat since they do not get their kind of food indoors.

Differences In Defensive Strategies

Centipede

• Their first pair of legs have a unique adaptation known as forcipules. At the end of each forcipule, there is a claw-like structure. This can hold on to the prey and pierce its body. There is a tube running from the venom gland to the tip of these claws. Once the skin gets pierced, the venom gets injected into the prey’s body to disable them.
• Their multiple legs get so arranged that they can quickly move towards shadows, away from the predator.
• Some centipede, secrete a sticky chemical substance, which contains foul odor and get made of hydrogen cyanide or benzoic acid. These are retardants to keep their predators away.

Millipede

• Except for the soft-bodied bristle millipede, the rest of the species have a hard exoskeleton to protect itself. When attacked, they wind themselves tightly, evading any external attack.
• They have specially developed body contours known as paranota, which helps them to burrow, bore, and barge into soil and crevices.
• There are pores along the entire body of millipedes. These secrete a sticky chemical containing phenols, alkaloids, benzoquinones, or hydrogen cyanide. These chemicals can scald the body of predators, including affecting eye and mouthparts.

Some Interesting Facts

Legs:Centipedes means a hundred legs, while millipedes suggest a thousand legs. However, in reality, none have this number of legs. Centipedes get to have an odd pair of legs. The last couple of legs of centipedes face backward and do not get used for walking. Millipedes use all their legs for walking, except the ones having gonopods in males.

Evolution:Both these arthropods are ancient creatures on this earth. There are historical facts, research findings, and fossil remain to prove their existence 300 million years ago.

Life span:Both live for long. Some species can live for around ten years.

Humans:Centipedes make humans panic for the following reasons:

• They dart towards shadows when the light gets suddenly switched on.
• The forcipule claws and venom is a deterrent factor among humans.

Both centipedes’ venom and chemical secretion of millipedes are not fatal to humans. They may cause irritation, inflammation, fever, and scalding. Getting the area washed with clean water and applying soothing gel should be sufficient enough unless there is any allergic reaction.

Conclusions

Centipedes and millipedes are both arthropods. Centipedes are of the Chilopoda family, while Millipedes are of Diplopoda class. There are similarities and differences among these creatures. Both have been in existence on this earth from ancient times.