Their family is represented around the world but only two Micruroides occur in the U.S. (Barbour & Ernst 1989). Ten percent of non-treated bites are fatal. Being a relative of the cobra, the bite fools you, small amount of pain and swelling at first, and small punctures. Powerful nerve toxin symptoms are delayed and can be fatal if not treated. Called the twenty minute snake because people believed you would die within that time. Since the venom is neurotoxic, more likely to occur in 24 hours. The coral snake is the only venomous snake in North America that lays eggs (Barket 1964, Stebbins 1966).
IUCN Red List of Threatened Species: least concern
Although it is not likely to be bitten by a wild coral snake, unless it is harassed, the venom is extremely toxic and can cause death.
Their neurotoxic venom is one of the venoms used in antiserum for snake bites. Venom is also being researched like many other venomous snakes. Research is being done for cancer, AIDS, and other disabilitating diseases. Without these animals for research we may lose many key cures.
M. fulvius' diet consists mostly of snakes, including its own species. It also eats lizards, birds, frogs, fish, and insects. It uses venom to kill its victims (Stebbins 1966).
There are five subspecies. M. f. fulvius occurs in southeast N. Carolina south through Florida and west to Louisiana. The other four range from western Louisiana southwest through southern Texas to eastern & central Mexico (Barbour & Earnst 1989).
Biogeographic Regions: nearctic (Native )
M. fluvius spends most of the time buried in the soil, in forest areas among decaying logs, leaves, and rocks. It seems to prefer dry, open or brushy areas, occasionally in marshy areas (Conant & Collins 1991).
Average lifespan
Status: captivity: 6.8 years.
Banded with red, white, or yellow and black on which the red and yellow bands lie beside each other, and the snout is black. Size ranges from two-three feet (Barket 1964). The body scales are smooth and occur in 15 rows throughout; the anal plate is divided.
Confusing species: several subspecies of Lampropeltis triangulum and the species Cemophora coccinea also have red, yellow and black bands crossing their bodies, but their red and yellow bands are separated by black bands and their snouts are red instead of black (Barbour & Ernst 1989).
M. fulvius breeds from late spring early summer and late summer to early fall. Eggs are laid during May to July. There are approximately 37 days between copulation and ovipostion. Clutches of 5-7 eggs will be laid and the young will hatch approximately 60 days later (Barket 1964, Stebbins 1966).
Females mature at a snout-vent length of about 55cm in 21-27 months. Males mature sexually usually around 45cm or longer reached in 11-21 months.
Ovary weights increase from March through April, and decline slightly in May and then more rapidly in June. There is complete regression with spermatogonia and Sertoli cells in May through August, with a peak in June (Barbour & Ernst 1989).
Southeastern USA from southeastern north Carolina through peninsular Florida westward to eastern and west-central Texas (apparently absent from the delta region of the lower Mississippi Valley), and southward into northeastern and central Mexico, including portions of the states of Tamaulipas, Nuevo León, Coahuila, Querétaro, San Luis Potosí, Hidalgo, Guanajuato, and morelos.
Holotype: not located, according to roze and Tilger, 1983, Cat. Am. Amph. Rept. 316:1-4[1].
Type-locality: Carolina. Restricted to vicinity of Chareston, South Carolina, USA, by Schmidt, 1953, Check List n. Am. Amph. Rept., 6th ed., 280 pp.[223].
Five subspecies, namely M. f. fulvius (Linnaeus, 1766); M. f. fitzingeri (Jan, 1858); M. f. maculatus Roze, 1967; M. f. microgalbineus Brown and Smith, 1942; and M. f. tener (Baird and Girard, 1853), were recognized by Roze and Tilger, 1983, Cat. Am. Amph. Rept. 316:1-4.
Micrurus fulvius, commonly known as the eastern coral snake,[3] common coral snake, American cobra,[4] and more, is a species of highly venomous coral snake in the family Elapidae. The species is endemic to the southeastern United States.[1] It should not be confused with the scarlet snake (Cemophora coccinea) or scarlet kingsnake (Lampropeltis elapsoides), which are harmless mimics.[3] No subspecies are currently recognized.[5]
M. fulvius is generally less than 80 cm (31 in) in total length (including tail). The maximum reported total lengths are 121.8 cm (48.0 in) for a specimen in Florida (Neill, 1958) and 129.5 cm (51.0 in) (Roze, 1996). Males have longer tails than females, but females reach a greater total length.[2]
The dorsal scales are smooth, and are in 15 rows at midbody.[3] The ventral scales number 197–217 in males and 219–233 in females. There are 40–47 subcaudals in males and 30–37 in females.[2] The anal plate is divided.[3]
The color pattern consists of a series of rings that encircle the body: wide red and black rings separated by narrow yellow rings. The head is black from the rostral scale to just behind the eyes. This snake commonly has a black snout as well as black eyes and then a yellow band on the back half of their head behind the eyes. [6] The red rings are usually speckled with black.[3] People who live in its natural range are often taught a folk rhyme as children such as: "Red next to black, safe from attack; red next to yellow, you're a dead fellow," or "Red touching black, friend of Jack; red touching yellow, you're a dead fellow", or simply "red and yellow kill a fellow".[7] These rhymes are useful in teaching children to distinguish king snakes (Lampropeltis ssp.), which are considered helpful predators of vermin such as rats and mice, from the venomous coral snake, which should only be handled by an experienced biologist or herpetologist. However, this rhyme is only applicable to the United States species, and cannot be used reliably in the Caribbean, or Central or South America.
Among the many common names for M. fulvius are eastern coral snake,[3] American cobra, candy-stick snake, common coral snake, coral adder, Elaps harlequin snake, Florida coral snake, harlequin coral snake, North American coral snake, red bead snake, thunder-and-lightning snake,[4][2] and, in Spanish, serpiente-coralillo arlequín (literally "harlequin coral snake").[5]
M. fulvius is found in the Southeastern United States from southeastern North Carolina, south through South Carolina and peninsular Florida, and westward through southern Georgia, Alabama and Mississippi to southeastern Louisiana. Coral snakes in Texas, western Louisiana, and southeastern Arkansas are now considered to be a different species, Micrurus tener, which was previously considered a subspecies of M. fulvius. M. fulvius may be found at altitudes of near sea level to about 400 m (1,300 ft).[2] The current range of the eastern coral snake is predicted to expand as a result of climate change. [8]
M. fulvius occurs in upland mesophytic and tropical hammocks in Florida, as well as glade land, high pine, scrub oak and live oak hammock, slash pine and wiregrass flatwoods. In southern Georgia and Florida, it is found in dry areas with open ground that are bushy but not heavily vegetated. It is associated with sandy ridges in Mississippi and sandy creek bottoms in Louisiana.[2] It is rarer in North and South Carolina, but is more typically found there in the scrub oak forests and pitch pine habitats near the coast, as well as the coastal plain of the southeast.
M. fulvius eats lizards, birds, frogs, fish, insects, and smaller snakes, including other coral snakes.[3][9][10] M. fulvius will attack the head of its prey first in order to envenomate it.[11] M. fulvius will hold on to the prey until it becomes paralyzed. After the prey is paralyzed the snake will consume it.[11]
Females of M. fulvius are reported to lay three to 12 eggs in June that hatch in September. Neonates are 18–23 cm (7.1–9.1 in) in length.[3] Males mature 11–16 months after hatching while females mature approximately 26 months after hatching. Adult females are typically larger than males.[12]
Coral snakes spend most of their time underground (fossoriality) or sheltering under suitable objects, but can be active on the surface during the day in early sprint or at other times when rainfall has saturated the ground. They appear not to be generally surface active at night. Coral snakes are largely diurnal making night sightings are rare[13] Males are most active in the late fall or early spring, when they search for mates, and females are most active in late summer and throughout the fall, when they search for prey that will allow them to build energy reserves for the next season's reproductive effort. Coral snakes will attempt to escape if discovered, and individuals may engage in complex defensive behavior if prevented from doing so. This includes hiding the head beneath the body coils, mimicking the head with their tail (for example, crawling backward and striking with the tail), erratic body movements, and death feigning. Other individuals can be touchy, and will readily bite if restrained in any way.[14]
The venom of M. fulvius is a potent neurotoxin with a median LD50 of 1.3 mg/kg SC.[15] Envenomation causes rapid paralysis and respiratory failure in prey. In humans, symptoms include slurred speech, double vision, and muscular paralysis eventually leading to respiratory failure.[16]
M. fulvius bites and fatalities are very rare. Only two documented fatalities were attributed to this species in the 1950s, and only one has been reported since Wyeth antivenin became available for it in the 1960s. The snakes have a mortality rate between 5–20%. The most recent fatality attributed to the eastern coral snake occurred in 2006 (confirmed in 2009 report).[17] The victim failed to seek proper medical attention and died several hours after being bitten, becoming the first fatality caused by M. fulvius in over 40 years.[17]
M. fulvius does not account for many cases of snakebite in the U.S., with only about 100 bites each year.[18] The snake is considered secretive and generally reluctant to bite (its venomous potential was still being debated in the 1880s), and envenomation (i.e., secretion of venom during a strike) is thought to occur in only 40% of all bites.[2] Unlike New World pit vipers, this New World coral snake cannot control the amount of primarily neurotoxic venom injected. Dry bites often result from a near miss or deflection; although the venom an adult coral snake holds is enough to kill up to five adults, it cannot release all its venom in a single bite.[19][20] Historically, however, the mortality rate was estimated to be about 10–20%, with death occurring in as little as one to two hours, or as much as 26 hours after the bite. This is not that surprising, since the LD100 for humans is estimated to be 4–5 mg of dried venom, while the average venom yield is 2–6 mg with a maximum of more than 12 mg. This is probably why current standard hospital procedure in the U.S. is to start with antivenin therapy for coral snake bites, even if no symptoms are found yet.[2]
Wyeth discontinued the manufacture of coral snake antivenin in 2010, citing a lack of profitability.[18] Pfizer has also decided to halt production of its antivenin for similar reasons (see Coral snake antivenom shortage). As of July 2021, Pfizer indicates that antivenom is available[21] and one source states that production has resumed.[22]
Micrurus tener used to be considered a subspecies of M.Fulvius. However DNA analysis suggests that it may be its own species as the analysis of microsatellites loci seems to place M.tener as a distinct species from M.fulvius.[23]
Micrurus fulvius, commonly known as the eastern coral snake, common coral snake, American cobra, and , is a species of highly venomous coral snake in the family Elapidae. The species is endemic to the southeastern United States. It should not be confused with the scarlet snake (Cemophora coccinea) or scarlet kingsnake (Lampropeltis elapsoides), which are harmless mimics. No subspecies are currently recognized.