''Micrurus frontalis'', also known as the southern coral snake or short-tailed coral snake, is a species of highly venomous

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

in the family

Elapidae Elapidae (, commonly known as elapids , from , variant of "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 '' Emydocephalus ...

. It is found in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Description

This species grows on average to 75 cm in length, with a maximum of 164 cm already reported. The color of the head varies, with a gray pigment on the top of the snout. The body pattern consists of very wide red bands that are separated by a series of 10–15 narrower black triads with 3 blacks separated by narrow white bands. The dorsal scales are red, with black tips of dark appearance. The tail has two complete triads. It is a

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

and fossorial snake, which digs loose soil or litter, has been one of the main accident-causing corals in Southeast South America, although it is not relatively aggressive towards humans, it has

Oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

reproduction, although eggs / clutch has not been reported.

Distribution and habitat

''Micrurus frontalis'' is found in south-central

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

, and northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. It mainly lives in humid forests, tropical and subtropical deciduous forests, savannas, sandy and rocky areas, in secondary vegetation such as pastures and agricultural land, close to marshes and streams, it inhabits lowlands, from sea level to an elevation of 700 m.

Diet

It feeds on

lizards Lizard is the common name used for all squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The ...

and other

snakes Snakes are elongated Limbless vertebrate, limbless reptiles of the suborder Serpentes (). Cladistically Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales much like other members of ...

(including blind snakes).

Cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is also well document ...

has been reported in this species.

Venom

Like all elapids in Brazil, ''Micrurus frontalis'' has post-synaptic neurotoxins (except for '' Micrurus corallinus'') that bind to terminal motor acetylcholine receptors, the toxin is composed of low

molecular weight A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...

polypeptides, which are rapidly absorbed by the body after inoculation and symptoms can appear in minutes, the toxin acts peripherally, blocking neuromuscular transmission. Muscle paralysis is a consequence of the action of the toxin with the neurotransmitter by the nicotinic receptor on the end plate. At the site of the bite,

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

and

paresthesias Paresthesia is a sensation of the skin that may feel like numbness (''hypoesthesia''), tingling, pricking, chilling, or burning. It can be temporary or chronic and has many possible underlying causes. Paresthesia is usually painless and can oc ...

occur, the initial systemic symptoms of most coral accidents, include eyelid ptosis and

diplopia Diplopia is the simultaneous perception of two images of a single object that may be displaced in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occ ...

, which are followed by facial muscle paralysis, visual impairment,

anisocoria Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems. Causes Anisocoria is a common cond ...

dysarthria Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. It is a condition in which problems effectively occur with the ...

dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

salivation Saliva (commonly referred as spit or drool) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DN ...

and generalized loss of muscle strength, in severe cases, life-threatening

respiratory arrest Respiratory arrest is a serious medical condition caused by apnea or respiratory dysfunction severe enough that it will not sustain the body (such as agonal breathing). Prolonged apnea refers to a patient who has stopped breathing for a long period ...

occurs, with patients requiring

artificial ventilation Artificial ventilation or respiration is when a machine assists in a metabolic process to exchange gases in the body by pulmonary ventilation, external respiration, and internal respiration. A machine called a ventilator provides the person air ...

. The median lethal dose is 22 μg for mice weighing 4–29 grams, and 0.69 mg/kg. The estimates of average yield range between 10 and 30 mg (dry weight), depending on the source.

References

frontalis Reptiles of Argentina Snakes of Brazil Reptiles of Paraguay Reptiles described in 1854 Taxa named by André Marie Constant Duméril Taxa named by Gabriel Bibron Taxa named by Auguste Duméril {{Elapidae-stub