Coluber guttatus sellatus
The Corn Snake or Red Rat Snake (Elaphe guttata) is a species of Rat Snake. The Latin word elaphe means deerskin. Popular in the pet trade, they are known for being smaller and less aggressive than other Rat Snake species. They are non-venomous, another reason why they are often kept as pets. Their average adult length is about 1-6 feet and they may live to be 30 years old in captivity. They are found throughout the south-eastern and central United States as well as parts of Mexico. The name 'corn snake' refers to the splotched pattern on its belly, which resembles Indian maize. Some, however, believe it is because they are often found in corn fields searching for mice.
There are two subspecies of Pantheropis guttatus, referred to as the Corn Snake or Red Rat Snake and the Emory's Rat Snake or Great Plains Rat Snake:
- Common Corn Snake (Pantheropis guttatus) is prevalent in the southeastern United States and is distinguished by having orange skin with red blotches, the blotches having black borders.
- Great Plains Rat Snake (Pantheropis emoryi) is prevalent in both central North America and also parts of Mexico. Some have also been seen as far North as Michigan and east to Massachusetts. Great Plains Rat Snakes are less colorful than the nominant species, often being light gray or tan with dark gray blotches, sometimes with a hint of olive green. However, the Emory subspecies has a lot of yellow pigmentation in its genetics that have been monopolized by the pet trade. This subspecies is often stouter and larger and produces fewer eggs per clutch than its predominantly southeastern counterpart. While Great Plains Rat Snakes can be kept as pets, some individuals are more aggressive than the guttata subspecies.
In 2002, all North American rat snakes of the genus Elaphe were suggested for reclassification into the genus Pantherophis, thus changing the scientific name of the Corn Snake from Elaphe guttata to Pantherophis guttatus, however many people have not accepted the change, and it is still widely referred to as Elaphe.
In 2003 Herpetological Review rejected the change from Elaphe to Pantherophis on the basis that further research was needed. Furthermore, the International Committee for Zoological Nomenclature has not ruled on the change. Taxonomic changes do not become official until they are approved by the ICZN, until such time any published articles with reclassification of the taxonomic names are regarded as taxonomic suggestions. Official taxonomy, whether used or not, remains with the older nomenclature until changes are approved by the ICZN.
Wild Corn Snakes prefer habitats such as overgrown fields, forest openings, and abandoned or seldom used buildings.
In the wild, Corn Snakes tend to be quite secretive and appear to be active mostly at night. During daylight hours they may be found hiding under loose tree bark and beneath logs, rocks, and other debris.
Corn snakes, as with all Rat Snakes, have a diet primarily consisting of rodents, but they are proficient climbers and may scale trees in search of birds, bird eggs and bats. As litters of infant mice are difficult to find in nature, many baby Corn Snakes are known to eat small lizards as their first meals, and Carolina anoles are the preferred choice. Some individuals retain these dietary tendencies well into adulthood. Pet corn snakes are usually fed by their owners on a diet of commercially available rodents, predominantly mice.
Corn Snakes as pets
Corn snakes are ideal pets and are one of the most widely available snakes in the pet trade. They are a good choice for a beginner snake keeper due to the fact that Corn Snakes have a comparatively docile temperament, are robust, and are more tolerant of basic husbandry mistakes than most other snakes. Also, Corn Snakes are widely captive bred, so healthy specimens are readily available. Corn snakes can live as long as 30 years in captivity, averaging closer to 15-20 years.
No matter how easily corn snakes can be kept, intensive research must be carried out before obtaining one, as their care needs are relatively complex. A vet that treats reptiles must also be sought beforehand, as few vets practice "exotic" medicine.
The advice provided here is basic and not adequate reading on its own. Research should cover multiple sources, including books. Always inquire in to the legality of corn snake ownership in your local jurisdiction. Certain jurisdictions outlaw the trade and/or ownership of native non-venomous species.
Selection of a Specimen
When looking for corn snake specimens look for healthy individuals. Emaciated or sickly specimens have loose or sagging skin. Other signs of poor health may include and are not limited to incomplete shedding, sores on the skin, scar tissue, bubbles or mucus around the mouth and lethargic behavior. Always inspect specimens closely for ectoparasites such as mites or ticks. It is generally wise to avoid purchasing wild caught specimens.
Setting up a Vivarium
A basic vivarium (or "terrarium") for a corn snake should consist of at least: a 20 gallon or larger vivarium (30" x 12½" x 13") with secure screen cover, a suitable substrate (no pine or cedar,) a heater set between 80-85 ºF, a water dish and a hide at both the warm and cool end. The vivarium should be fully set up before obtaining a snake, as this will allow you to observe and adjust the temperatures beforehand. Only one corn snake should be kept in a vivarium or other enclosure. Keeping multiple snakes together can lead to the spread of diseases or parasites, or it can even lead to cannibalism.
A hide should be placed at each end of the temperature gradient, as this will allow the snake to thermoregulate without the fear of being forced out into the open. Hides can be as simple as cardboard boxes and should be replaced when soiled (along with the bedding immediately surrounding it.) A more natural look can be obtained by purchasing half-log hides and hides that resemble rock formations.
Placement of a Vivarium
The correct placement of a vivarium can reduce stress. Incorrect placement can lead to a nervous and unhealthy animal. The vivarium should be:
- Away from audio equipment such as stereos. Snakes "hear" through vibrations and the vibrations from a constant bassline can upset them. If this cannot be achieved padding underneath the vivarium can help reduce the vibrations.
- Away from rooms next to busy roads. Once again, the vibrations can cause stress to the snake.
- Up off the floor to prevent drafts chilling your snake, and to prevent some inevitable vibrations.
Captive corn snakes should only be fed commercial mice, as wild caught prey can carry diseases or parasites. Sizes range from "pinkie" to adult, and most pet stores carry all sizes in both live and frozen varieties, the latter of which being the preferred choice as live mice can cause injuries. However, some snakes refuse to eat dead mice. Frozen mice should be thawed completely before being offered. Mice should be no larger than thickest part of the snake, and should generally be given once a week. There is disagreement as to whether multiple mice should be given at one time, but it is widely known that a snake that is given a mouse that is too large will often have problems with digestion, often regurgitating the mouse.
A heat gradient must be provided so that the snake can thermoregulate. The warm end must have an ambient temperature of 80-85F. Temperatures that are too hot or too cold will result in an ill snake that cannot digest its meals properly.
Heat can be provided via a light bulb (it is wise to provide a guard for this so that the snake cannot touch it), an undertank heat mat or a ceramic heater. Heating devices should be controlled by thermostats. Hot rocks should never be used. They cause a dangerous source of localized heat. Many snakes have been severely burned by these devices. It causes thermal burns.
Two thermometers should be used to measure temperature - simply guessing the temperature is not adequate. Two thermometers - one at each end of the vivarium - allow you to observe the heat gradient.
Fecal matter and molting should be removed immediately. At least once a month a substantial cleaning should be performed, in which the bedding is replaced. The tank and everything in it should also be washed with a weak bleach solution during this time, as this will ensure that the environment stays relatively sterile and also helps prevent the growth of parasites.
Although docile, corn snakes - like all animals - can be stressed by excessive handling. Not handling a specimen at all is also not advised as you may find yourself with a snake that reverts to wild behaviour and cannot be handled at all. Handling your snake also lets you check for any abnormalities which may require the attention of a vet. Handling benefits your snake in that it exercises and can explore something other than its enclosure. Although snakes are not as intelligent as a dog or cat, environmental stimulation should be provided.
Corn snakes can be active when held and must be supervised constantly when out of their vivariums.
It is highly recommended that you do not handle your snake for at least three days after it has eaten, to allow it time to digest its food. Handling too soon after a feed will result in regurgitation, which can be serious.
While it is easy to avoid unexpected clutches of eggs with most species of snakes by denying them of brumation, or an artificial hibernation period, corn snakes will readily breed in captivity without any hibernation period. The eggs should be stored in moist vermiculite or sphagnum moss between 78 and 90 degrees Fahrenheit (26 to 32 degrees Celsius). Unlike most birds' eggs, the eggs must not be rotated or repositioned past the first few days after laying. If they are kept warm and moist the baby snakes should emerge after 70 days.
After many generations of selective breeding, domesticated corn snakes are found in a wide variety of different colors and patterns. These result from recombining the dominant and recessive genes that code for proteins involved in chromatophore development, maintenance or function.
- Miami Corn (Florida wildtype) These are usually a smallish corn snake with better specimens having high contrasting light silver to gray ground color with orange blotches surrounded in black. Selective breeding has lightened the ground color and darkened the blotches. The "Miami" name, coined by Rich Zuchowski, now is considered an appearance trait. Many Miami corn snakes are difficult to start feeding as hatchlings, as they prefer lizards. Miami corns, unlike other varieties, will often readily accept anoles as food for life. This can simplify feeding for residents of Florida, but care should be taken to avoid introducing parasites from wild caught food.
- Okeetee Corns (classic corns, South Carolina wildtype) These snakes are characterized by deep red dorsal blotches surrounded by very black borders. The ground color varies with bright orange being the most desirable. As with the Miami phase, selective breeding has changed the term "Okeetee" to an appearance trait rather than a local designation. Over hunting in their natural range for the pet trade has caused a decline in wild Okeetee specimens. Responsible purchasers should seek captive bred Okeetees.
- Amelanistic (red albino) corn snakes, produced from a single recessive genetic mutation, show wide variations in colors. They can be almost solid orange, to a dark orange on a light orange background, or red/orange on a very light background. These varying color schemes are due to reflective cells in the skin and iridophores which may contribute to subtle shades of color. These red eyed snakes lack the melanin pigment.
- Candy Cane corn snakes are created with the goal of obtaining bright red blotches on a white background. Some on the market originate solely from selectively breeding Miami corns. Others are produced using light creamsicle (emory/albino corn hybrids x corn) bred with Miami phase corns. Most candy canes develop orange coloration around the neck region as they mature. Their bright red markings as hatchlings often fade with maturity.
- Albino Okeetee (reverse okeetee) an amelanistic okeetee corn snake which has the normal black rings around blotches replaced with wide white rings. Most are high contrast snakes with light orange to yellow background and dark orangish/red saddles. Note: Albino Okeetees are not okeetees, they are selectively bred amelanistics
- Sunglow corn snakes are another designer albino corn that lacks the usual white speckling that often appears in most albinos. The orange background surrounds dark orange blotches.
- Charcoal These Anerythristic type 'B' snakes are lacking the yellow color pigment usually found in all corn snakes. This morph is the starter for blizzard corns.
- Anerythristic (black albino) are the compliment to amelanism. The inherited recessive mutation of lacking erythrin (red, yellow, and orange) pigments produce a snake that is mostly black and gray. When mature, many type A anerythristic corn snakes develop yellow on their neck regions. In 1984 a wild caught Type B anerythristic corn snake was caught which is the ancestor of anerythristics missing the yellow neck regions. Similar snakes include: stonewashed -- copper or light brown blotches; charcoal (aka muted anerythristic, Pine Island anerythristic)-- type B anerythristic, very low contrast with shaded of gray on white and black background.
- Snow (white albino) are a blending of the amelanistic and anerythristic recessive traits. These predominantly white snakes tend to have yellow neck and throat regions when mature. Light blotches and background colors have subtle shades of beige, ivory, pink, green, or yellow.
- Blizzard corns resulted from a type B anerythristic corn caught in 1984. Blizzards are a totally white snake with very little to no visible pattern.
- Hypomelanistic or rosy corn snakes carry a recessive trait that reduces the dark pigments causing the reds, whites, and oranges to become more vivid. Their eyes remain dark. These snakes range in appearance between amelanistic corns snakes to normals with greatly reduced melanin.
- Ghost corn snakes are a hypomelanistic anerythristic (type A) snakes. They exhibit varying shades of grays, browns, and blacks on a lighter background. These often create pastel colors in: lavenders, pinks, oranges, and browns.
- Bloodred corn snakes carry a recessive trait that eliminates ventral checkered patterns. These originated from a somewhat unicolor Jacksonville and Gainesville, Florida strain of corn snake. Through selective breeding, an almost solid ground color has been produced. Hatchlings have a slight pattern that fade as they mature into a solid orange red to ash red colored snake. The earlier bloodreds tend to have large clutches of smaller than average eggs that produce hard to feed offspring. Through out crossing with amelanistic and anerythristic corns hatchlings tend to be larger with fewer feeding problems.
- Butter corns (snow caramel) cultured by Rich Zuchowski from a female purchased in Florida marked with blotches on an unusual straw colored background. Selective breeding has produced intense yellow colored corns snakes with yellow markings.
- Caramel corns are another Rich Zuchowski engineered corn snake. The background is varying shades of yellow to yellow brown. Dorsal blotches vary from caramel yellow, brown, and rich chocolate brown.
- Amber corns are a hypomelanistic caramel snake with amber markings on a brownish background.
- Lavender corn snakes contain a light pink background with darker purple gray markings and burgundy eyes or lavender gray blotches on an orangish background. Variation with this same genetic strain are arguably called: mocha, cocoa, and chocolate.
- Albino lavender look like blizzard corns once mature with pink to purple highlights.
- Crimson (hypomelanistic Miami) are very light high contrast snakes with a light background and dark reddish/orange blotches.
- Fluorescent orange develop white borders around bright red blotches as adults on an orange background.
- Pewter or Peppercorn (Type B Anerytheristic blood red) are silvery lavender with very slight blotches as adults.
- Creamsicle are hybrids between an albino corn snake and an emory's ratnsake/common corn cross. These snakes bring out the yellow and downplay the reds of the corn snake. Most are varying shades of yellow with darker yellow to orangish blotches. Clutches are generally smaller in number but produce larger more vigorous hatchlings. Creamsicle with less emory background and increased amelanistic corn generally have lighter backgrounds and red to orange saddles(red creamsicle).
- Jungle corns are hybrids using the corn snake and California Kingsnake (Lampropeltis getula californiae). These show extreme pattern variations taking markings from both parents -- sometimes looking very similar to one parent or the other. However, as a hybrid of different species, these attractive snakes are typically sterile.
- Aztec: blotches and spots are exhibited in various sizes
- Milksnake phase: banded blotches resembling coastal plains milk snake.
- Motley: a catch all name for irregularities -- ranging from exhibiting an aberrant line of light colored spots, fused blotches, to stripes down the back
- Striped phase: a single stripe running longitudinally from head to tail
- Zigzag (zipper): dorsal blotches connected forming a "zigzag" type pattern
See also the Jungle variety listed under colors.
- Pantherophis replaces Elaphe. Utiger, Helfenberger, Schatti, Schmidtkutrjytdf(2002) Russian Journal of Herpetology 9(2): 105-124.
-  Taxonomy citation
- Taxonomy Citation - Herpetological Review