| Scolopendra heros | |
|---|---|
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Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Myriapoda |
| Class: | Chilopoda |
| Order: | Scolopendromorpha |
| Family: | Scolopendridae |
| Genus: | Scolopendra |
| Species: | S. heros |
| Binomial name | |
| Scolopendra heros Girard, 1853 | |
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| Approximate distribution ofS. heros | |
| Synonyms[1] | |
Scolopendra heros, commonly known as theArizona desert centipede,giant desert centipede,giant Sonoran centipede,Texas black-tailed centipede,Texas redheaded centipede, andgiant redheaded centipede, is a species ofNorth Americancentipede found in theSouthwestern United States andNorthern Mexico.
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S. heros is the largest centipede in North America.[2] It has an average length of 6.5 inches (170 mm), but can reach up to 8 in (200 mm) in the wild,[3] and even longer in captivity.[4] Its trunk bears either 21 or 23 pairs of legs.[5][6]
It isaposematically colored, to warn off potentialpredators, and a number of color variants are known in the species.[3] Thecastaneiceps variant found in Arkansas,[3] Missouri,[2] Texas,[4] and other nearby areas is commonly known as the "giant redheaded centipede" or "Texas redheaded centipede" because of its distinct red head and greenish black body and tail.
S. heros is found in northernMexico and the southwesternUnited States, fromNew Mexico andArizona in the west toArkansas,Missouri, andLouisiana in the east. Although this species is commonly referred to as the "giant desert centipede" because of its presence in theSonoran andChihuahuan Deserts, and otherarid andsemi-arid habitats,S. heros is also found in rocky woodland areas, such as in Arkansas.[3] It remains underground on warm days, emerging in cloudy weather.[7]
S. heros is primarily anocturnal predator and hunts invertebrates and small vertebrates, including rodents, reptiles, and amphibians. It is capable of reaching into the air to grab small flying insects. The centipede uses its venom to subdue prey.[4]
S. heros hatch from eggs. As they grow and mature, like all arthropods they shed and molt away their exoskeleton. Each time they molt they enter a new stage of its life cycle called an instar. Like all Scolopendromorph centipedes, the number of segments they possess remains the same throughout their life.S. heros is a slow-growing species capable of living over a decade.[8]
The venom ofS. heros is similar in composition to the venom of otherScolopendra species, including components such asserotonin,histamine,lipids,proteins (includingcardiotoxic proteins andenzymes such ashemolyticphospholipase A), and other substances. The mixture is known to act as acytolysin, compromising cellular membranes and rupturing cells.[9][10]S. heros venom also contains toxins targeted to its prey: one toxin numbs the nervous system of insects, rendering them unable to sense or escape, while another toxin interferes with theautonomic nervous system of vertebrates to make small vertebrates easier to subdue and devour. The exact effects and makeup of the venom have not been thoroughly evaluated, in part because it is difficult to extract in significant quantities and quickly deteriorates when processed.[5]
S. heros bites are very painful to vertebrates.[4] A rat bitten byS. heros in the leg showed signs of excruciating pain, followed by soreness, but returned to normal after five hours.[11] For humans, a bite fromS. heros usually causes sharp, searing, local pain and swelling,[11][12] but has never caused any confirmed deaths.[4]S. heros bites are known to occasionally causenausea,headache, and localizedskin necrosis.[4] However, there are individual cases of severe symptoms and injury (includingkidney failure due torhabdomyolysis, andheart attack) in humans resulting fromScolopendra bites.[4][10]