Centipedes

 __The World of Centipedes__

​The World of Centipedes  Introduction

 Centipedes have large antennae and have only one pair of legs per body segment. The last legs extend backwards behind the body. Centipedes can run fast and can bite. (Compare differences with millipedes in See Also section below.)There are five orders: Geophilomorpha, Scolopendromorpha, Craterostigmomorpha, Lithobiomorpha, and Scutigeromorpha. They have 15 to 177pairs of legs, and are always an odd number. They live in moist areas such as leaf litter, under logs or rocks. They are predatory animals, they use "poison claws" to seize a variety of smaller organisms such as worms and insects, which are killed by the venom. Some centipedes occasionally feed on plants.  Classification Kingdom Animalia (Animals) Phylum Arthropoda (Arthropods) Subphylum Myriapoda (Myriapods) Class Chilopoda (Centipedes) []

Body characteristics Centipedes are arthropods belonging to the class Chilopoda and the Subphylum Myriapoda. They are elongated metameric animals with one pair of leg s per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. All centipedes always have an odd number of pairs of legs, e.g. 15 or 17 pairs of legs (30 or 34 legs) but never 16 pairs (32 legs). A key trait uniting this group is a pair of venom claws or forcipules formed from a modified first appendage. Centipedes are mainly carnivorous taxon. Centipedes normally have a dull coloration combining shades of brown and red. Body Systems

Centipedes breathe by taking oxygen openings along sides of their body called spiracles. They are located between the upper and the lower chitinous shields and just behind the legs. The air travels through slender tubes called trachae. The trachea filters oxygen into the body by process called diffusion. They lead into larger tracheal chambers that branch off to supply the various parts of the body with oxygen. Blood flows through a tube, which is located directly under the exoskeleton on its back. The centipede’s nervous system consists of a relatively large brain connected with two nerve cords. The centipede’s eyes are simple, seeing only the shadows of light, therefore their smelling and touching sense are very strong. [] Feeding habits Centipedes are carnivores that use venom to kill their prey. The venom comes from glands that open near the first pair of modified legs; their bite can be painful to a human but not lethal. Centipedes eat insects, earthworms, spiders, slugs, and other small animals. The largest centipede, Scolopendra gigas also eats mice and some small lizards. Scolopendra gigas grows to be about 10 inches (25 cm) long and 1 inch wide .

Reproduction of Centipedes

Most species must mate to reproduce. The male places a sperm packet in a web Centipedes are found on the ground. He then pushes the female to the web by tapping her back legs with his antennae. This process may last for hours. Eventually the rear of her body comes into contact with the web and she takes the packet into her reproductive organs. A few kinds species have become widespread, accidentally carried to other parts of centipedes are capable of parthenogenesis, where the young developes from an unfertilized egg. Only females can be produced by this method of reproduction which is asexual. Some species of centipedes lay their eggs one at a time. In other species the female digs out holes in rotten wood or soil and lays up to eighty or more eggs all at once. She wraps her body around her eggs and cleans them constantly so funguses, molds, or predators do not harm them. Some of these species some will eventually camouflage the eggs with bits of soil and abandon them. Others will remain with their eggs, even until after they hatch. Since they are unable to hunt and remain with their mother until after their next molt, or shedding of their hard outer coverings or exoskeletons. Young centipedes resemble small adults. However, depending on the species, they may not hatch with their full number of legs. Additional pairs of legs and body segments are added as they molt (form). For example, hatchlings of house centipedes have only four pairs of legs, while the adults have fifteen. Stone centipedes hatch with six to eight pairs of legs, while the adults have fifteen. In other groups of species, such as the earth-loving centipedes and scolopenders, off-springs come into the world with plants or soil.



Habitat (Ara Yerevanian)

Centipedes habitat differs from sea level to high mountain peaks. A few species prefer to live in caves. Some individual species are found in a wide variety of situations under bark, in leaf litter, or under rocks. Cavernicolous and subterranean species may lack pigmentation and many tropical Scolopendromorphs have bright aposematic colors. Behavior 

Most centipedes are active at night. During the day they seek shelter under objects on the ground, inside logs and stumps, or in animal burrows. During the hot dry weather they will usually bury themselves deep in the soil. They are not territorial and move about the environment in search of food and mates. Centipedes live alone until they are ready to mate or when they are raising their young. When they do meet, they are often very aggressive toward one another and will sometimes eat the other. Some species living along the seashore hunt in packs. Several individuals will feed together on the same animal, usually a barnacle or beach hopper. When threatened, centipedes protect themselves by running away or biting. Others whip their bodies about or spread their hind legs wide in a threatening manner. Some species fool predators by having markings that make them look as if they have two heads. Others release bad smelling and tasting chemicals from glands on their undersides. In one group of centipedes, these chemicals actually glow in the dark. A few centipedes produce glue that hardens within seconds when exposed to air. This sticky stuff can tangle up the legs of even the largest insect predators.



Centipedes harm toward Humans

Centipedes will bite humans, and the bites of large or even moderate-sized centipedes can be quite painful. Their bodies are so long and flexible that they can bend around and bite an attacker if grasped at the tail end. Bites vary with the species, but they produce moderate to severe pain for a few hours and may cause localized swelling, discoloration, and numbness. The only recorded human fatality is a child in the Philippines, who was bitten on the head and the poison was injected indirectly into the brain. If children, elderly, or allergic persons are bitten, medical assistance may be necessary. But unlike scorpions and spiders, there are no really dangerous deadly centipedes. Difference Between Centipedes and Millipedes. Centipedes belong to their own class – Chilopoda. The name originates from the Greek //cheilos//, meaning lip, and //poda//, meaning foot. The millipedes belong to a separate class, Diplopoda. Also from the Greek, Diplopoda means double foot.
 * Characteristic || **Centipede** || **Millipede** ||
 * **Antennae** || long || short ||
 * **Number of Legs** || one pair per body segment || two pairs per body segment, except for the first three segments, which have one pair each ||
 * **Appearance of Legs** || visibly extend from sides of body; trail backward behind body || do not visibly extend from body; rear leg pairs in line with body ||
 * **Movement** || fast runners || slow walkers ||
 * **Ability to Bite** || can bite || do not bite ||
 * **Feeding Habits** || mostly predatory || mostly scavengers ||

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Extra Questions: 1. State the differences between centipedes and millipedes. 2. How are centipedes harmful to humans

(pictures by: Ara Yerevanian)


 * __ Interesting Facts about Centipedes (By: Ara Yerevanian) __**

**. ** Centipede means “hundred feet”, but centipedes actually have between 15 to over one hundred pairs of legs. Centipedes have one pair of legs on each segment. When a centipede moves backwards, its last pair of legs is used just like feelers. Although all centipedes are terrestrial, meaning they live on land, they require moist environments. Centipedes alternate the movement of the legs on opposite sides of the body like insects do. Centipedes are often confused with millipedes because they look similar. Centipedes have poisonous bites. Millipedes do not.
 * . ** Centipedes are not insects but belong with the insects in the phylum arthropoda. All arthropods have bodies made of many parts or segments. They also have an exoskeleton, which is a hard covering on the outside of their bodies that functions like a skeleton. Arthropod means jointed legs or appendages. Appendages of arthropods may be modified for feeling, feeding, walking, and sometimes swimming.
 * . ** The legs of the first body segment are actually claws. These claws contain toxins, or poisons, and are used to attack and capture prey. They feed on prey such as insects.

**Centipedes and their Adaptations** (By: Wissam Moujaes)

Physical Adaptations: Freeze tolerant: In winter, centipedes are freeze tolerant however, the conditions of the freezing point or temperature. The centipede can only stand the freezing point of -1c. If the temperature decreased to -6c the centipede would be safe under a log because insulation provided the overwinter microhabitat is important for survival. Heat tolerant: Centipedes like and live in the heat it is not a danger or trouble to them at all. They stay in the sun and move regularly to their direction. Water tolerant: Centipedes are to both hot and cold water tolerant but for super cooling water can be injurious or fatal to them. They should stay hidden or away from winter, weather, water, or it will be fatal.