''Micruroides'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

coral snake 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 16 species of Old World coral snakes, in three genera (''Calliophis'', '' Hemibungar ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Elapidae Elapidae (, commonly known as elapids ; grc, ἔλλοψ ''éllops'' "sea-fish") is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus Emydoce ...

. The genus is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

, containing only the

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

''Micruroides euryxanthus''. ''Micruroides euryxanthus'', commonly known as the Sonoran coral snake, Western Coral Snake or the Arizona coral snake, is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to northwestern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

and the southwestern United States.

Description

Adults of ''M. euryxanthus'' are long. The color pattern consists of broad, alternating rings of red and black, separated by narrower rings of white or yellow. Markings become paler as they reach the belly. The head is black,Reptiles and Amphibians of Arizona. www.reptilesofaz.org/Snakes-Subpages/h-m-euryxanthus.html. the black extending to the posterior border of the parietals. The smooth

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down t ...

are arranged in 15 rows at midbody. The

ventrals In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that cont ...

number 214–241. The

anal plate Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving s ...

is divided. The

subcaudals In snakes, the subcaudal scales are the enlarged plates on the underside of the tail.Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . These scales may be either single or divided (pair ...

number 21–34, and are divided (paired). Smith HM, Brodie ED Jr (1982). ''Reptiles of North America: A Guide to Field Identification''. New York: Golden Press. 240 pp. (paperback). ("Elapidsfamily Elapidae" and ''"Micruroides euryxanthus"'', pp. 196–197). ''Micruroides euryxanthus'' resembles ''

Micrurus fulvius ''Micrurus fulvius'', commonly known as the eastern coral snake, Behler John L.; King, F. Wayne (1979). ''The Audubon Society Field Guide to North American Reptiles and Amphibians''. New York: Alfred A. Knopf. 743 pp., 657 color plates. LCCCN 7 ...

''. However, the white or yellow rings are broader than in ''M. fulvius'', and there are fewer black rings on the tail, usually only 2. Also, the first ring on the body (the first ring behind the white or yellow ring on the back of the head) is red, whereas in ''Micrurus fulvius'' it is black.

Venom

The

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a st ...

of ''M. euryxanthus'' is

neurotoxic Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specificall ...

and extremely potent, but no fatalities have been reported.

Habitat

''M. euryxanthus'' is found in arid and semiarid regions in numerous

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s, both on plains and on lower mountain slopes, from sea level to . In Arizona it is abundant in rocky upland desert.

Behavior

The Sonoran coral snake usually stays underground and comes out at night, but can also appear during and after rains.

Defense

When startled, frightened, or threatened, ''M. euryxanthus'' will hide its head under its body and raise and tightly curl its tail. While in this posture, it will "fart": snakes do not have an anal cavity in the sense that humans and most mammals do, but rather a tract that allows for both disposal of waste and for laying of eggs in females. Instead, it will forcibly and noisily emit gas from its cloaca, a behavior known as "cloacal popping", and predictably this phenomenon has a very unpleasant smell.

Diet

The Arizona coral snake

preys Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

upon small snakes, predominantly '' Rena (snake)'', but also '' Sonora'', and ''

Tantilla ''Tantilla'' is a large genus of harmless New World snakes in the family Colubridae. The genus includes 66 species, which are commonly known as centipede snakes, blackhead snakes, and flathead snakes.Wilson, Larry David. 1982. Tantilla. ...

''.Hubbs B, O'Connor B (2012). ''A Guide to the Rattlesnakes and other Venomous Serpents of the United States''. Tempe, Arizona: Tricolor Books. 129 pp. (paperback). (''Micruroides euryxanthus euryxanthus'', pp. 86-87, 122). It will also eat small lizards such as skinks.

Reproduction

Like all other species of

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...

coral snakes ( genera '' Leptomicrurus'' and ''

Micrurus ''Micrurus'' is a genus of venomous coral snakes of the family Elapidae. Geographic range Species in the genus ''Micrurus'' are endemic to the Americas. Species The following 83 species are recognized as being valid. *'' Micrurus albicinctus'' ...

''), ''Micruroides euryxanthus'' is oviparous. Adult females may lay up to 3

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s, and each hatchlings is in total length.

Geographic range

''Micruroides euryxanthus'' is found from central

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and southwestern

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

Mazatlán Mazatlán () is a city in the Mexican state of Sinaloa. The city serves as the municipal seat for the surrounding '' municipio'', known as the Mazatlán Municipality. It is located at on the Pacific coast, across from the southernmost tip ...

in southern Sinaloa. Isolated populations are also found in the

Chocolate Mountains The Chocolate Mountains of California are located in Imperial and Riverside counties in the Colorado Desert of Southern California. The mountains stretch more than 60 miles (100 km) in a northwest to southeast direction, and are located ea ...

La Paz County La Paz County is the 15th county in the U.S. state of Arizona, located in the western part of the state. As of the 2020 census, its population was 16,557, making it the second-least populous county in Arizona. The county seat is Parker. Th ...

, western Arizona and on

Tiburón Island Tiburón Island is the largest island in the Gulf of California and the largest island in Mexico, with an area of . It was made a nature reserve in 1963 by President Adolfo López Mateos. Etymology is Spanish for 'shark'. Although the Seri nam ...

in the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

. Stebbins RC (2003). ''A Field Guide to Western Reptiles and Amphibians, Third Edition''. The Peterson Field Guide Series ®. Boston and New York: Houghton Mifflin. 533 pp. (paperback). (''Micruroides euryxanthus'', pp. 405–496 + Plate 44 + Map 181).

Subspecies

Three subspecies are recognized, including the

nominotypical subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

."''Micruroides euryxanthus'' ". ITIS (Integrated Taxonomic Information System). www.itis.gov. *''

Micruroides euryxanthus australis ''Micruroides'' is a genus of venomous snake, venomous coral snake in the Family (biology), family Elapidae. The genus is Monotypic taxon, monotypic, containing only the species ''Micruroides euryxanthus''. ''Micruroides euryxanthus'', commonly ...

'' *''

Micruroides euryxanthus euryxanthus ''Micruroides'' is a genus of venomous snake, venomous coral snake in the Family (biology), family Elapidae. The genus is Monotypic taxon, monotypic, containing only the species ''Micruroides euryxanthus''. ''Micruroides euryxanthus'', commonly ...

'' *''

Micruroides euryxanthus neglectus ''Micruroides'' is a genus of venomous coral snake in the family Elapidae. The genus is monotypic, containing only the species ''Micruroides euryxanthus''. ''Micruroides euryxanthus'', commonly known as the Sonoran coral snake, Western Coral Sn ...

'' ''

Nota bene (, or ; plural form ) is a Latin phrase meaning "note well". It is often abbreviated as NB, n.b., or with the ligature and first appeared in English writing . In Modern English, it is used, particularly in legal papers, to draw the atten ...

'': A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than ''Micruroides''.