Құрғақ жылан тұқымдастарының кең тобы

Large group of elapid snakes

Coral snakes are a large group of elapid snakes that can be divided into two distinct groups, the Old World coral snakes and New World coral snakes. There are 27 species of Old World coral snakes, in three genera (Calliophis, Hemibungarus, and Sinomicrurus), and 83 recognized species of New World coral snakes, in two genera (Micruroides and Micrurus). Genetic studies have found that the most basal lineages have origins in Asia, suggesting that the group originated in the Old World. While new world species of both genera are venomous, their bites are seldom lethal; only two confirmed fatalities have been documented in the past 100 years from the genus Micrurus. Meanwhile, snakes of the genus Micruroides have never caused a medically significant bite.

Experts now recognize that certain coloration patterns and common mnemonics—such as the phrase “Red against yellow, deadly fellow; red against black, friendly Jack,” which people sometimes use to distinguish between the venomous coral snake and the non venomous milksnake—are not consistent enough to be trustworthy. While any snake exhibiting the coral snake's color and/or banding pattern in the southeastern United States will almost certainly, in fact, be a coral snake, there are coral snakes in other parts of the world which are colored differently. Coral snakes in the United States are most notable for their red, yellow/white, and black colored banding. However, several nonvenomous species in the U. S. have similar (though not identical) bandings, including the two scarlet snake species in the genus Cemophora, and some of the kingsnakes (including the aforementioned milksnakes) in the genus Lampropeltis. However, in reference to the mnemonic phrase “red touching yellow, a deadly fellow,” some of these kingsnakes do not naturally display any red touching yellow, to begin with. Additionally, some ground snakes in the genus Sonora (of the southwestern U. S.) can have a color pattern that matches that of the sympatric Sonoran coral snake (Micruroides euryxanthus). No genuine coral snake in the U. S. exhibits red bands of color, in contact with bands of black, except in rare cases of an aberrant pattern. Thus, while on extremely rare occasions when a certain non venomous snake might be mistaken for a coral snake, the mnemonic holds true. However, a red–yellow–black banded snake in the U. S. (whose red and black banding actually touch) is rarely a venomous coral snake. Furthermore, the mnemonic is not consistently accurate for North American coral snake species found south of the U. S., either. Some species, like Mexico’s Oaxacan coral snake (Micrurus ephippifer) or Clark's coral snake (Micrurus clarki, of Costa Rica & Panama), do actually fit the mnemonic; others, like the Honduran Roatan coral snake (Micrurus ruatanus), or the redtail coral snake (Micrurus mipartitus) of Panama, do not. Further still, some South American coral snakes will fit the mnemonic, while others do not. To complicate the issue more, the South American tricolored hognose snake (Xenodon pulcher) has repeated bands of red black white black, imitating the coral snake as a defense mechanism, with the key visual difference being their upturned snout (used for burrowing). The hognoses are, actually, mildly rear fanged venomous; although generally not considered serious to humans, anecdotal research has suggested the South American hognoses to possess slightly more potent venom than the North American hognoses. In the Old World, none of the coral snake species usually fit the mnemonic. Most species of coral snake are small in size. North American species average around 3 feet (1 m) in length, but specimens of up to 5 feet (2 m) or slightly larger have been reported. Some coral snakes even live in the water but most of them do not. Aquatic species have flattened tails that act as fins, aiding in swimming.

Coral snakes vary widely in their behavior, but most are very elusive, fossorial (burrowing) snakes which spend most of their time buried beneath the ground or in the leaf litter of a rainforest floor, coming to the surface only when it rains or during breeding season. Some species, like Micrurus surinamensis, are almost entirely aquatic and spend most of their lives in slow moving bodies of water that have dense vegetation. Coral snakes feed mostly on smaller snakes, lizards, frogs, nestling birds, small rodents, etc. Like all elapid snakes, coral snakes possess a pair of small hollow fangs to deliver their venom. The fangs are positioned at the front of the mouth. The fangs are fixed in position rather than retractable, and rather than being directly connected to the venom duct, they have a small groove through which the venom enters the base of the fangs. The venom takes time to reach full effect. Coral snakes are not aggressive or prone to biting and account for less than one percent of the total number of snake bites each year in the United States. The life span of coral snakes in captivity is about seven years.

M. fulvius reproduction is internal fertilization through the use of hemipenes. The breeding season occurs from spring to early summer and late summer to early fall. Male combat is not typical in M. fulvius as males are smaller than females. Micrurus fulvius are oviparous and typically lay eggs from May to July. During early spring females will undergo sudden vitellogenesis–oocyte and yolk formation–in preparation for breeding. Approximately 37 days post fertilization oviposition occurs and the average clutch size ranges from five to seven eggs. However, some in captivity have laid as many as thirteen eggs. The incubation period of the M. fulvius eggs normally reaches 60 days. However, males typically have mature sperm residing in the epididymis year round and are capable of storing sperm in the deferent duct over the winter till the females are receptive. A study investigating how climate influences the reproductive cycle discovered species found closer to the equator displayed more continuous cycles while those in colder regions had more seasonal cycles. With increasing temperatures as a result of climate change, continuous cycles have the possibility of becoming more prevalent. There is controversy about the classification of the very similar Texas coral snake as a separate species. Its habitat, in Texas, Louisiana, and Arkansas is separated from the eastern coral snake's habitat by the Mississippi River. The coral snake population is most dense in the southeastern United States, but coral snakes have been documented as far north as Kentucky. The Arizona coral snake is classified as a separate species and genus and is found in central and southern Arizona, extreme southwestern New Mexico and southward to Sinaloa in western Mexico. It occupies arid and semiarid regions in many different habitat types, including thornscrub, desert scrub, woodland, grassland and farmland. It is found in the plains and lower mountain slopes, at elevations ranging from sea level to 5800 feet (1768 m); often found in rocky areas.

New World coral snakes possess one of the most potent venoms of any North American snake. However, relatively few bites are recorded due to their reclusive nature and the fact they generally inhabit sparsely populated areas. Even in areas that are densely populated, bites are rare. According to the American National Institutes of Health, there are an average of 15–25 coral snake bites in the United States each year. When confronted by humans, coral snakes will almost always attempt to flee, and bite only if restrained. In addition, coral snakes have short fangs (proteroglyph dentition) that cannot penetrate thick clothing although bites are possible through normal thin clothing. Any skin penetration, however, is a medical emergency that requires immediate attention. Historically, the venom of the North American Micrurus and Micruroides species was believed to contain powerful neurotoxins which could paralyze the breathing muscles, requiring mechanical or artificial respiration. It was usually reported that there was only mild pain associated with a bite and that respiratory failure could occur and onset of clinical symptoms may be delayed for as much as 10 to 18 hours. Coral Snake venom contains a neurotoxic component and symptoms include pain from the bite, sialorrhea, paresthesia, ptosis, weakness, blurred vision, paralysis, fasciculation and diplopia. However recent studies on the bites of at least the Texas Coralsnake (Micrurus tener) have shown that these bites rarely require antivenom, don't usually show any systemic respiratory problems and can be intensely painful. Further studies are necessary to see if these clinical features are true of all Micrurus species. Body length in coral snakes appears to be positively associated with venom yield. Shortages of coral snake antivenom were previously reported, but one source states that production has resumed and, as of 2021, Pfizer indicates that antivenom is available.