Eastern Coral Snake


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Photos Courtesy of Kenneth L. Krysko, Dr. Robert Sprackland, R.W. Vandevender, Bill Love, and National Aquarium of Baltimore

Taxonomic History
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Micrurus
Species: Micrurus fulvius fulvius


      Species designation of fulvius fulvius within the genus Micrurus is currently hotly debated. Originally classified as Micrurus fulvius by Linnaeus in 1766. Southern populations of M. fulvius were once recognized as a separate species called M. fitzingeri, which is included now as a subspecies of M. fulvius. The subspecies tener was also cited as a separate species by Collins in 1991. This was due to the opinion that any allopatric subspecies in some way morphologically distinct is considered a separate species. Dowling in 1993 and others cited by Dowling rejected the Collins taxonomic classifications, and they provided taxonomic classifications based on data coming from an examination of specimens. Previously a simple examination of inaccurate range maps and old subspecies descriptions provided the material for species classification. (Collazo, 2002)

Taxonomic summary as follows:
Micrurus fulvius fulvius  Linnaeus, 1766
Coluber fulvius  Linnaeus, 1766: 381
Elaps fulvius  Fitzinger, 1826:61
Vipera fulvia  Harlan, 1827:364
Elaps fulvius   Baird & Girard, 1853: 21
Elaps fulvius   Dumeril & Bibron, 1854: 1215
Elaps fulvius   Boulenger, 1896
Micrurus fulvius   Stejneger and Barbour, 1917:106
Type location is Charleston, S.C. in the United States by Schmidt (1953).
Holotype is not located, probably female, and collected by D. Garden, no date.
Micrurus fulvius fulvius   Conant & Collins, 1991: 224
Micrurus fulvius fulvius  Welch, 1994: 83
(Ernst & Barbour, 1989; Uetz, 2002)

Species Description
      Physical length: 20-30 inches(51-76cm); average 60cm; record 47.5 inches(120.7cm). This snake species shows sexual dimorphism, as males are usually 45 cm longer.(King, 1999)
      Physical description: Eastern Coral snake is characterized by red and yellow rings which touch which encircle the entire body. The end of the snout is black with a yellow parietal band and a black nuchal band on head. Head is ventrally colored yellow or white. Black ring on the neck separated from the parietal scutes along with red rings containing black spots are found. Some species found in Florida may lack dark spots on the red rings. Males have 10-27 black bands and females have 12-26. Anal plate is divided. Hemipenis is 12-14 subcaudal scales in length. It is bifurcated at the 8th subcaudal with each fork tapering toward the apex. Each fork ends in spiny papillae. As characteristic of Elapid snakes, the Eastern Coral snake has permanent, erect, hollow proteroglyphous fangs near the front of the maxillae. The venom duct is not attached to the fang directly but enters a small cavity in the gum above the entrance lumen of the gum. The males have 185-217 ventrals and 36-47 pairs of subcaudals. Females have 205-232 ventrals and 26-38 pairs of subcaudals. (Roze & Tilger, 1983) Also, pupils are round and dark. Scales are smooth. No loreal pits are found near mouth.(King, 1999)
  Lifespan: Body size doubles in less than 2 years. Natural longevity is unknown although longest lifespan recorded is 7 years.(Ernst & Barbour, 1989)
      Several harmless snakes have color patterns similar to coral snakes. A coral snake always has a blunt black snout and red, yellow, and black rings that completely encircle its body. Yellow ring on both sides of every red ring is found on venomous corals. Remember: "Red touch yellow, kill a fellow." Harmless Scarlet Kingsnakes, a type of Milk Snake, resembles the coral snake but has a red snout. The red and yellow rings are separated by black rings: "Red touch black, friend of Jack." Nonvenomous Scarlet Snakes have rings that do not completely encircle its body. The belly is white, the snout is red and pointed, and the red areas are ringed in black, unlike corals. (King, 1999)
   

     
Courtesy of Wayne King.

    Photo courtesy of Barry Mansell

  Head scalation:
  Dorsal a rostral, 2 internasals, 2 prefrontals, a frontal, 2 parietals, 2 supraoculars
  Lateral a preocular, 2 nasals, 2 postoculars, 1+1 temporals, 7 supralabials
  There are no loreal nor subocular scales.
(Ernst & Barbour, 1983)

Museum Specimen Collections

Biogeography
      Eastern Coral snakes are found in the lowlands of southern North Carolina to southern Florida and Key Largo. They are also found west through the Gulf States to western central Mississippi and Louisiana. They are not present in the delta region of lower Mississippi Valley areas. There is a population in central Alabama. The other subspecies of Micrurus fulvius extend into Louisiana, Texas, and parts of Mexico.(Ernst & Barbour, 1989)

Range maps

Reproductive Behavior
      Mating is during the spring and also in autumn. The snakes are aggressive toward each other, and fighting may ensue. 2-13 elongate eggs develop and are laid in underground cavities and in logs from May to July. Females mature usually after 2 years after they have reached a snout-vent length of 55cm. Ovarian follicles reach preovulatory size around June. Males mature sexually in less than two years after reaching a snout vent length of 40.2cm. Active spermatogenesis occurs from August to April. The Eastern Coral snake gestation period is 70 to 90 days, hatching in August or September.(Ernst & Barbour, 1989) Young have similar pattern and color morphology as adults with length ranging from 18-23cm when hatching.(Conant & Collins, 1998)

Feeding Mechanism and Diet
      The Eastern Coral snake eats several lizard and smaller snake species including members of its own species. Also, birds, frogs, fish, and insects are included in its diet. Random head pokes into leaf and other vegetation debris is used to search for prey.(Ernst & Barbour, 1989)
      The coral snake venom is injected using a pair of small, fixed, hollow fangs on the anterior of the mouth. The chewing motion passes the venom into its victim. In order to attain significant passage of venom, the snake must hold onto its victim for a brief period. Coral snake venoms have significant neurotoxins causing neuromuscular dysfunction. There is no appreciable enzymatic activity or necrotic potential compared to vipers and pit vipers.(Norris, 2001)

Lifestyle
      The coral snake is found during the daytime and in the morning. They are most active during early evening and morning. Often they are found in wooded or marshy macro-habitats. These snakes inhabit the soil, logs, or leaf and debris piles. It also makes pine and scrub oak forests with sandy soils its micro-habitat. They are semi-fossorial. This species is secretive and solitary. Even when breeding they can be aggressive towards each other. (King, 1999)
      The coral snake is often imitated in nature by various snakes. The coral snake is venomous, and its imitators are nonvenomous. Many species have the red, black, and yellow or white rings of the coral snake. These imitators, however, all have a black ring separating the red from yellow. If the red and yellow bands touch, the snake is the venomous Eastern Coral. Some imitators include the Scarlet snake, the Scarlet Kingsnake, and several Milk snake species. (King, 1999)
      Coral snakes are shy and bites are uncommon. Most coral snakes bites are due to direct handling, and bites often occur in the active season for the snakes in spring or fall. The Eastern Coral has one of the most powerful venoms found in snakes. Included in this family are other notoriously venomous snakes such as the cobras, mambas, and sea snakes. Still, it produces less than venom per snake than that of most vipers or pit vipers. Because of the relatively primitive venom delivery method of the Eastern Coral, as many as 60% of those bitten may go unaffected. The Eastern Coral is able to swings its tail and mimic its head movements. This serves as a defense mechanism. It will also make a popping sound with its vent lining.(Norris, 2001)

Conservation
      It is important to keep the Coral snake population preserved. The Coral snake is a marvel of coloration morphology and is well worth the effort to maintain these beautiful creatures in the wild. It is found in marshy and wooded areas, so deforestation and pollution of nearby streams and marshes from industrial or roadside runoff would be detrimental to the population. Fortunately, it is not included in endangered or threatened species lists.
Venomous snakes offer uses in medical research and has benefited people in blood pressure medicine. Venom was developed for monitoring blood pressure using the chemical pattern of snake venom as a guide. Other techniques include using snake poisons to treat blood and heart problems and control harmful bacteria in humans.(Shannon, 1999)
      Many Eastern Coral snakes control snake and lizard populations including venomous ones, that are considered pests. The Eastern Coral can pests at a reasonable level because these snakes can capture pests in areas small for larger predators.

Useful Links

Fort Matanzas National Monument.
http://www.flmnh.ufl.edu/natsci/herpetology/FOMA/mfulvius.htm

Georgia Museum of Natural History.
http://museum.nhm.uga.edu/gawildlife/reptiles/squamata/serpentes/elapidae/mfulvius.html

Myherp.com.
http://www.myherp.com/articles/species%20spotlight/coral.htm

Reptiles and Amphibians
http://www.snakesandfrogs.com/scra/snakes/coral.htm

University of Georgia.
http://www.uga.edu/~srelherp/snakes/coral.htm

Heidelberg University
http://www.embl-heidelberg.de/~uetz/LivingReptiles.html

Bibliography

Photo Credits

     
Courtesy of American Museum of Natural History and Carl S. Lieb