Texas coral snake
| Texas coral snake | |
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Elapidae |
| Genus: | Micrurus |
| Species: | M. tener
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| Binomial name | |
| Micrurus tener | |
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| Synonyms[2] | |
Micrurus tener, commonly known as the Texas coral snake, is a species of venomous snake in the family Elapidae. The species is native to the southern United States and adjacent northeastern and central Mexico. Six subspecies are recognized as being valid, including the nominotypical subspecies, Micrurus tener tener[1][2] The species Micrurus tener was once considered to be a subspecies of the eastern coral snake (Micrurus fulvius).
Geographic range
[edit]
The Texas coral snake ranges from the southern United States south to northeastern and central Mexico. It inhabits the states of Texas, Louisiana and Arkansas, and the Mexican states of Tamaulipas, San Luis Potosí, Guanajuato, Querétaro and Morelos.[2]
Description
[edit]The Texas coral snake has the traditional coloration associated with coral snakes: black, yellow, and red rings.[3] These rings extend onto their belly.[4] It is capable of growing to 48 in (122 cm) in total length (including tail), but most are closer to 24 in (61 cm).[3] Males are typically smaller than females.[5] It has smooth dorsal scales, a rounded head, and the eyes have round pupils. Albinistic (lacking black pigment) and anerythristic (lacking red pigment) specimens have been found in the wild.[citation needed] "Pastel" (pink, translucent cream, and very light blue) coloration has been noted, and completely black (melanistic) specimens, are known.[citation needed] The Texas coral snake is somewhat larger (longer and stouter) than the eastern coral snake (Micrurus fulvius), and has a somewhat larger venom yield.[citation needed]
Behavior
[edit]All coral snakes are shy, secretive animals, typically nocturnal. They spend most of their time hiding in leaf litter, under logs. They can be seen crawling on the surface, after heavy rains, when the nighttime temperatures rise above 78 °F (26 °C).[citation needed]
When grabbed suddenly, or sometimes just when touched, they may thrash about, swing around, and bite. Sometimes they are calm, and then suddenly swing around and bite, for no apparent reason.[citation needed]
Diet
[edit]The primary diet of the Texas coral snake consists of other snakes, primarily earth snakes, and other small fossorial species.[6] It is cannibalistic.[7] It also occasionally eats small lizards,[6] but the consumption of rodents by coral snakes is rare.[citation needed]
Reproduction
[edit]The Texas coral snake is oviparous.[3]
Mimicry
[edit]Other nonvenomous snakes resemble the Texas coral snake as a form of Batesian mimicry. In the United States only, all three species of venomous coral snakes (Micruroides euryxanthus, Micrurus fulvius, and Micrurus tener) can be identified by the red rings contacting the yellow rings. A common mnemonic device is "red and yellow, kill a fellow. Red on black, friend of Jack". However, this mnemonic is not always accurate, due to the aforementioned color variations, and its usage is dangerous to both snakes and humans.[3]
Venom
[edit]
Coral snakes are proteroglyphous, meaning they have a pair of deeply grooved, semihollow, chisel-shaped, fixed fangs in the front of its upper jaw, through which venom is injected. Though it was previously thought that they to need to gnaw to inject venom, Coral snakes need only a quick bite to deliver a significant amount of venom. Many bites from coral snakes do not inject any venom at all (known as a dry bite).[citation needed]
Texas coral snake venom contains neurotoxin and myotoxin. Bite victims may experience potentially lethal paralysis or myolysis. Immediate first aid measures for a bite can include removing any jewelry on a limb that has been bitten (in case of severe swelling) and wrapping the bite area moderately tightly in a wide cloth; however, the bitten limb should be moved as little as possible. Bite victims should be taken to the nearest hospital as soon as possible for more advanced lifesaving measures, such as application of antivenom.[8]
The Texas coral snake can deliver 10-12 mg of venom in a single bite.[8]
Because of the low profits, the production of coral snake antivenin has been discontinued for several years.[9][10] Prior to the availability of antivenin, the fatality rate of coral snake envenomations has been estimated at 10%, and death was primarily due to respiratory or cardiovascular failure as a result of paralysis induced by the neurotoxic venom.[citation needed]
Wyeth Pharmaceuticals, a wholly owned subsidiary of Pfizer, produced antivenin for the eastern coral snake, which can also be used for treatment of envenomation by the Texas coral snake. However, the last lot produced (Lot L67530) has an expiration date of January 31, 2020.[11] As of July 2021,[update] Pfizer indicates that antivenom is available[12] and one source states that production has resumed.[13]
Subspecies
[edit]The six recognized subspecies of M. tener are:
- M. t. tener (Baird & Girard, 1853)
- M. t. fitzingeri (Jan, 1858)
- M. t. bernadi (Cope, 1887)
- M. t. maculatus Roze, 1967
- M. t. microgalbineus B.C. Brown & H.M. Smith, 1942
- M. t. tamaulipensis Lavin-Murcio & Dixon, 2004
Nota bene: A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than Micrurus.
M. t. tener is found in both the U.S. and Mexico, whereas the other four subspecies are endemic to Mexico.[2]
Etymology
[edit]Their Latin name tener means "soft of delicate". This is in reference to the graceful features of the snake.
The subspecific name, fitzingeri, is in honor of Austrian herpetologist Leopold Fitzinger.[14]
The name maculatus (Latin for spotted) refers to the presence of some large black spots in the red bands.
The name microgalbineus is derived from a modern Latin adaptation of the original Greek word micro meaning small and tiny and galbineus, Latin for greenish yellow. The name microgalbineus alludes to the short yellowish bands of this subspecies. [15]
Taxonomy
[edit]The Texas coral snake was once considered a subspecies of the eastern coral snake, Micrurus fulvius, but more recent research has determined that it has enough morphological differences to be considered its own species.[1]
References
[edit]
- ^ a b c Hammerson, G.A.; Lavin, P.; Mendoza Quijano, F. (2007). "Micrurus tener ". IUCN Red List of Threatened Species. 2007: e.T64033A12738512. doi:10.2305/IUCN.UK.2007.RLTS.T64033A12738512.en. Retrieved 20 November 2021.
- ^ a b c d Species Micrurus tener at The Reptile Database
- ^ a b c d Powell R, Conant R, Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 Figures. ISBN 978-0-544-12997-9. (Micrurus tener, pp. 434-435, Figure 196 + Plate 44).
- ^ "Micrurus tener tener Texas Gulf-Coast Coralsnake | Herps of Arkansas". 2022-03-26. Retrieved 2023-03-31.
- ^ Quinn, Hugh R. (1 August 1979). "Reproduction and Growth of the Texas Coral Snake (Micrurus fulvius tenere)". Copeia. 1979 (3): 461. doi:10.2307/1443222. hdl:11244/19160. JSTOR 1443222. Retrieved 2 September 2022.
- ^ a b Tivador, Edward J.; et al. (2011). "A Photographic Record of a Rare Ophidian Predation Event". Southeastern Naturalist. 10 (3): 561–562. doi:10.1656/058.010.0317. JSTOR 41262936. S2CID 84739734. Retrieved 2 September 2022.
- ^ Curtis, Lawrence (15 July 1952). "Cannibalism in the Texas Coral Snake". Herpetologica. 8 (2): 27. JSTOR 20171236. Retrieved 2 September 2022.
- ^ a b "Micrurus tener". Clinical Toxinology Resources. The University of Adelaide, Australia. Retrieved 28 March 2024.
- ^ Breen, David (11 October 2013). "Risk from coral-snake bites grows as antivenin dwindles". Orlando Sentinel. Retrieved 9 September 2022.
- ^ Roser, Mary Ann (22 September 2012). "Snake bite but no antidote for dog, and dwindling supply for humans". Austin American Statesman. Retrieved 9 September 2022.
- ^ "Expiration Date Extension for North American Coral Snake Antivenin (Micrurus fulvius) (Equine Origin) Lot L67530 through January 31, 2020". Food and Drug Administration. Retrieved 9 September 2022.
- ^ "Antivenin (Micrurus fulvius equine origin) North American Coral Snake Antivenin". Pfizer Hospital US. Archived from the original on 1 March 2021. Retrieved 9 July 2021.
- ^ Greene, Spencer (9 April 2021). Alcock, Joe (ed.). "What is the treatment for coral snake envenomation?". Medscape. Archived from the original on 1 March 2021. Retrieved 9 July 2021.
- ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Micrurus tener fitzingeri, p. 91).
- ^ "Micrurus tener". The Reptile Database. Retrieved 2023-03-31.
Further reading
[edit]- Baird SF, Girard C (1853). Catalogue of North American Reptiles in the Museum of the Smithsonian Institution. Part I.—Serpentes. Washington, District of Columbia: Smithsonian Institution. xvi + 172 pp. (Elaps tenere, new species, pp. 22–23).
- Brown BC, Smith HM (1942). "A New Subspecies of Mexican Coral Snake". Proceedings of the Biological Society of Washington 55: 63–65. (Micrurus fitzingeri microgalbineus, new subspecies).
- 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. ISBN 978-0-9754641-3-7. (Micrurus tener tener, pp. 89–90).
- Jan [G] (1858). "Plan d'une Iconographie descriptive des Ophidiens et Description sommaire de nouvelles espèces de Serpents ". Revue et Magasin de Zoologie Pure et Appliquée, Paris, Series 2, 10: 438–449, 514–527. (Elaps fitzingeri, new species, p. 521). (in French).
- Roze JA (1967). "A Check List of the New World Venomous Coral Snakes (Elapidae), with Descriptions of New Forms". American Museum Novitates (2287): 1-60. (Micrurus fulvius maculatus, new subspecies, pp. 27–28, Figure 10).
- Schmidt KP, Davis DD (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Micrurus fulvius tenere, pp. 274–276).