Micrurus fulvius

Micrurus fulvius
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia Order: Squamata Suborder: Serpentes Family: Elapidae Genus: Micrurus Species: M. fulvius
Binomial name
Micrurus fulvius (Linnaeus, 1766)
Synonyms
Coluber fulvius - Linnaeus, 1766 Elaps fulvius - Daudin, 1803 Vipera fulvia - Harlan, 1826 Elaps tristis - Baird & Girard, 1853 Elaps fulvius - Boulenger, 1896 Micrurus fulvius fulvius - Schmidt, 1928 Micrurus fulvius barbouri - Schmidt, 1928 Micruroides fulvius - Stickel, 1952

Common names: eastern coral snake, American cobra, candy stick, common coral snake, more.  
 
Micrurus fulvius is a venomous elapid species found in the southeastern United States. The venom is a neurotoxin that can be fatal if injected in a large enough dose, but under normal circumstances this is extremely unlikely to occur. Most bites result from the purposeful handling of the snake. It is not to be confused with its harmless mimics. No subspecies are currently recognized.

Description

This species is usually less than 80 cm in length; the largest recorded specimens are 121.8 cm for a specimen in Florida (Neill, 1958) and 129.5 cm (Roze, 1996). Males have longer tails than females, but females reach a greater total length.

There are 15 rows of smooth dorsal scales. Males have 197-217 ventral scales and females have 219-233. There are 40-47 subcaudals in males and 30-37 in females. The anal plate is divided.

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 to just behind the eyes. The red rings are usually speckled with black.

Common names

Eastern coral snake, American cobra, candy stick, common coral snake, coral adder, Elaps harlequin snake, Florida coral snake, garter snake, harlequin coral snake, king snake, North American coral snake, red bead snake, thunder-and-lightning snake, candy-stick snake, eastern coralsnake, Florida coralsnake, harlequin coralsnake, serpiente-coralillo arlequín (Spanish).

Geographic range

Found in the southeastern USA: southeastern North Carolina south through South Carolina and peninsular Florida, and westward through southern Georgia, Alabama and Mississippi to southeastern Louisiana. May be found at altitudes of near sea level to approximately 400 m.

Habitat

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. Associated with sandy ridges in Mississippi and sandy creek bottoms in Louisiana.

Feeding

Small snakes and lizards.

Reproduction

It is reported that they lay 3-12 eggs in June that hatch in September. Neonates are 18-23 cm in length.

Venom

Only two documented fatalities were attributed to this species in the 1950s and none have been reported since Wyeth antivenin became available for it in the 1960s. It does not account for many cases of snakebite in the USA because of its secretive nature and general reluctance to bite (its venomous potential was still being debated in the 1880s). In addition, it is estimated that envenomation occurs in only 40% of all bites. Historically, however, the mortality rate was estimated to be about 10-20%, with death occurring in as little as 1-2 hours, or as much as 26 hours post bite. This is not that surprising, since the LD₁₀₀ for humans is estimated to be 4-5 mg or dried venom, while the average venom yield is 2-6 mg with a maximum of more than 12 mg. This is probably why it is currently standard hospital procedure in the USA to start with antivenin therapy for coral snake bites even if there are no symptoms yet (since there may not be any noticeable localized symptoms).

Mimicry

This species should not be confused with its harmless mimics, the scarlet snake, Cemophora coccinae, and the scarlet kingsnake, Lampropeltis triangulum elapsoides. C. coccinae has red dorsal blotches bordered with black and an unpatterned whitish belly, while in L. t. elapsoides the red and yellow rings are separated by black and the snout is usually pale in color. Another species that may be confused with M. fulvius is the mud snake, Farancia abacura. However, its back is a shiny black with red or deep pink marking on its sides that are incursions from its belly coloration.

In areas where both the Eastern coral snake and species of its harmless mimic live, a simple rhyme is often helpful to the person in the field: "Red and yellow - kills a fellow, red and black - venom lacks". There are variations of this rhyme, which have been traditionally taught to local children (as well as visiting field biologists and reptile enthusiasts). The basis for the mnemonic is the fact that, in this particular region of the world, all of the nonvenomous mimics of Micruris fulvius have black bands separating the red and yellow bands. As this snake is highly venomous, but generally dangerous to the person who handles it, rather than simply passes by, it is important to be able to easily identify it in the field. Many herpetologists have emphasized simple rules for identifying this snake to those who might be tempted to catch it for a closer look. Roger Conant has advised, "think of a traffic stop; red means stop, yellow means caution. If these two warning colors touch on the snakes body, it is poisonous". Although this is useful advice in context, it only applies to the USA. There are venomous species elsewhere in which red and black bands do touch.