Elaphe

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Elaphe
'Elaphe climacophora in Yokohama.jpg
Japanese rat snake, E. climacophora
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Colubrinae
Genus: Elaphe
Wagler, 1833
Synonyms

Callopeltis, Elaphis, Scotophis

Elaphe is a genus of snakes in the family Colubridae. Elaphe is one of the main genera of the rat snakes, which are found in many regions of the northern hemisphere. Elaphe species are medium to large constrictors by nature.

Contents

Based on the mitochondrial DNA analysis results, many species of Elaphe have been moved to the genera Bogertophis , Coelognathus , Gonyosoma , Orthriophis, Pantherophis , Rhinechis , Senticolis , Zamenis , and others. [1] Nevertheless, the generic name Elaphe is still widely used.

Physical characteristics

Like most of the rat snakes, Elaphe spp. generally have slender but sturdy bodies, square heads, and extremely flat bellies. [2] Their sizes range from large medium to very large, [3] growing even as large as 2.75m (108 in). Elaphe spp. have large numbers of vertebrae, ribs, and ventral scales, but few rows of dorsal scales, which are characterized by having slight keels. In cross section, Elaphe spp. are shaped like a loaf of bread, the flat belly meeting the sides of the body at an angle. [4] This special physical characteristic is well observed in Elaphe obsoleta (now considered Pantherophis obsoletus ), whose belly scales curve upward. The curving of the ventral scales gives them better traction for tree climbing. [5] The color and pattern of Elaphe spp. are quite variable and hard to generalize. [5]

Internally, Elaphe spp. do not have any observable vestiges of hind limbs or coronoid bones of the lower jaw like any other members of the family Colubridae. Another important characteristic of Elaphe as part of the Colubridae is the presence of Duvernoy's gland, a modified salivary and digestive gland. [6] In addition, Elaphe spp. have equal and smooth maxillary teeth. [3] The teeth are small and slightly curved, and occur in several rows. The curved teeth help fix the prey and prevent them from escaping once they are caught. [1]

Senses

Elaphe spp. have very developed sensory organs which support their daily activities. They have internal ears that enables them to detect sounds at low frequencies. The ears consist of a single ear bone connected to a jaw bone. Compared to other snakes, they are considered to have highly developed vision that allows them to detect the movement of their predators and prey. The eyes are protected by single transparent brilles. In addition, the analysis of scents is carried out by Jacobson's organ in the palate. To stimulate Jacobson's organ, they use their tongues to transport air and ground molecules to Jacobson's organ. Then, the organ analyzes the molecules to identify the scent. Among these detectable scents are pheromones, which indicate the presence of other snakes and their reproductive readiness. [1]

Lifecycle and behavior

The lifespan of Elaphe spp. is generally 15 years. Males live a little longer than females, [7] but some species, such as E. guttata (now considered Pantherophis guttatus ), live up to 23 years in captivity. [8] However, species such as E emoryi (now considered Pantherophis emoryi ) usually have lifespans around 2 years and 2 months. [3]

Elaphe spp. generally reach sexual maturity after 18–24 months. They usually mate with the opposite sex after emerging from hibernation in the spring. The gestation period of females is around 1.5 months, and females can lay up to 30 eggs in a clutch, the number varying between species. E. guttata and E. obsoleta, among others, are mostly diurnal, but some species are more active in late afternoon or at dusk. Throughout the year, they are usually active from April to October, followed by a period of hibernation.

Hibernation

Elaphe spp. hibernate, especially those that live in cold regions, because snakes are cold-blooded, which makes their body temperature susceptible to the temperature of their environments. Thus, they need to maintain their body energy by switching locations and remaining physiologically inactive when winter comes. [9] The hibernacula sites vary depending on the habitats they live in, yet the most important requirement of a hibernaculum site is that it needs to be frost-free. Some Elaphe spp. hibernate in the rock crevices, rock faults, and burrows. [10] However, other species choose to hibernate in rotting logs, roots of trees, and hollow spaces in elevated tree trunks. Some snakes that live close to human communities even hibernate in old wells and barns. [11]

Most members of the genus Elaphe start their hibernation in October and emerge again the next spring. The length of the hibernation varies by species. Elaphe longissima , or Aesculapian snake, may hibernate from October to May, [10] as it is among the northernmost occurring rat snakes. However, Elaphe bimaculata , or the twin-spotted rat snake, only needs to hibernate for 2 to 3 months. [12] Species such as black rat snakes, or E. obsoleta, hibernate with other rat snakes and/or many other snake species, most notably timber rattlesnakes, racers, and bull snakes. [13]

Reproduction

E. obsoleta generally starts to mate in late April, May, and early June after the winter hibernation. Males try to attract females with pheromones, as the females pass through their territories. Male Aesculapian snakes pursue female snakes until they can coil around them. They continue in such position, which is then followed by dancing for up to an hour before copulation, during which the male snake lines up with the female and holds her in place by wrapping his tail around hers and grasping her with his mouth. Then, the male everts one of his hemipenes into the female's cloaca. The mating process lasts from a few minutes to a few hours. [14]

After copulation, Elaphe spp. seek an appropriate place to lay the developing eggs. They usually lay eggs in the soft heart of a rotten log or in sandy soil under a rock. A good place for laying eggs is one that is damp but not wet, and warm but not hot. After laying eggs, the female snake covers them up with sand or soil, and then she leaves. [15] A few species remain with the eggs until they hatch about 9 weeks later.

Oviparous E. obsoleta lays 12–20 eggs under logs or leaves in late summer, which hatch in the fall. The adult snakes return to their hibernation dens in the late fall. [13] E. guttata breeds from March to May. The mating process is similar to E. obsoleta. E. guttata lays 10–30 eggs in late May to July. The eggs are generally not protected by the adults. After 60–65 days, the eggs hatch in July through September. [8]

Defense mechanisms

Many species of Elaphe are known for being nonaggressive and shy. They are prone to freeze their movements when they are shocked or encountering danger. This motionless response has contributed to many road kills of Elaphe. However, some Elaphe spp. tend to be more defensive if they are continually provoked. For example, Texas rat snakes, Elaphe obsoleta lindheimeri , are well known as one of the most snappy and combative rat snakes. In general, their defense system can be broken down to two levels. The first line of defense involves specific behaviors that they use to warn the intruders. One of the most common ways is by coiling their bodies and vibrating their tails, which simulates a rattle. Fox snakes, Elaphe vulpina (now considered Pantherophis vulpinus ) and Elaphe gloydi (now considered Pantherophis gloydi ), exemplify this type of defense mechanism; they mimic the rattling vibration of rattlesnakes when they encounter danger. [2] Another common way of defense is by smearing a foul-smelling musk on their predators. The musk is originated from the contents of the anal gland and the intestinal tract. [1] The second line of defense, generally involves striking the intruder with their teeth if they are further provoked. [14]

Locomotion

Elaphe spp. move forward using side-to-side, serpentine movement. They use the curved ventral scales of their bodies to grab the rough ground surfaces and then push against the ground to generate a forward movement. Thus, the smoother the ground is, the harder it is for them to move across it. [1] Many species apply similar mechanisms when climbing trees.

Predation

Adult Elaphe spp. primarily prey on rodents (i.e., mice and chipmunks), bird eggs, and young birds. Juveniles feed on small lizards, young mice, and occasionally small frogs (i.e., tree frogs). Elaphe spp. hunt by waiting motionless in a fixed position until the prey comes near enough to attack. Then, they strike the prey and bite it. They use their Jacobson's organ to track and find their prey. [9] Being constrictors, Elaphe spp. kill the prey by creating enormous pressure on the prey's chest. As they continue to coil more tightly, the pressure on the chest prevents the blood from circulating into the heart, which eventually leads to heart failure. [16] They usually bite the prey first to maintain their grip on the prey before they start this deadly mechanism. In addition, they do not chew their food, but swallow it whole. [8]

Habitat and distribution

Elaphe spp. live in a great variety of environments, depending on species and subspecies. Most are terrestrial or semiarboreal, but some burrow in sand or loose soil. The genus formerly contained species found on every continent except Antarctica. Taxonomic revisions have renamed most of these former Elaphe, leaving only 10 Eurasian taxa remaining in Elaphe. [17]

Species

The following 18 species are recognized as being valid. [18]

Related Research Articles

<span class="mw-page-title-main">Rat snake</span> Common name for various snakes

Rat snakes are members – along with kingsnakes, milk snakes, vine snakes and indigo snakes – of the subfamily Colubrinae of the family Colubridae. They are medium to large constrictors and are found throughout much of the Northern Hemisphere. They feed primarily on rodents. Many species make attractive and docile pets and one, the corn snake, is one of the most popular reptile pets in the world. Like all snakes, they can be defensive when approached too closely, handled, or restrained. However, rat snake bites are not dangerous to humans. Like nearly all colubrids, rat snakes pose no threat to humans. Rat snakes were long believed to be completely nonvenomous, but recent studies have shown that some Old World species do possess small amounts of venom, though the amount is negligible relative to humans.

<span class="mw-page-title-main">Corn snake</span> Species of snake

The corn snake, sometimes called red rat snake, is a species of North American rat snake in the family Colubridae. The species subdues its small prey by constriction. It is found throughout the southeastern and central United States. Though superficially resembling the venomous copperhead and often killed as a result of this mistaken identity, the corn snake lacks functional venom and is harmless. The corn snake is beneficial to humans because it helps to control populations of wild rodent pests that damage crops and spread disease.

<i>Pantherophis obsoletus</i> Species of snake

Pantherophis obsoletus, also known commonly as the western rat snake, black rat snake, pilot black snake, or simply black snake, is a nonvenomous species of snake in the family Colubridae. The species is native to central North America. There are no subspecies that are recognized as being valid. Its color variations include the Texas rat snake. Along with other snakes of the eastern United States, like the eastern indigo snake and the eastern racer, it is called “black snake”.

<span class="mw-page-title-main">Beauty rat snake</span> Species of snake

The beauty rat snake, also called the beauty ratsnake, the beauty snake, or the cave racer, is a species of snake in the family Colubridae. The species is native to the eastern and southeastern regions of Asia. It is a long, thin, semi-arboreal species of snake with several recognized subspecies. This constrictor feeds on rodents, and though it is favored in some locations as a natural pest control or pet, it is also considered an invasive species in other locations.

<i>Pantherophis</i> Genus of snakes

Pantherophis is a genus of nonvenomous colubrid snakes endemic to central and eastern regions of North America. It consists of the North American ratsnakes, the foxsnakes, and the cornsnakes. The genus, which contains 10 recognized species, first appeared in the fossil record in the Middle Miocene around 16.3 million years ago. They are a large terrestrial snake genus that lack subocular scales. Originally classified in the genus Elaphe, phylogenetic studies have found this taxon to be closely related to Pituophis. As with all snakes Pantherophis is an obligate faunivore with a diet that consists of small mammals, birds, reptiles and amphibians, and even insects. While many species conservation status is categorized as "least concern", many local populations in some species have declined where some places have them listed as federally protected. The corn snake is a popular pet reptile, due to the availability of captive-bred animals, their low maintenance and calm disposition, and the variety of color morphs. There are other species of Pantherophis that are in the pet trade, though are not as popular as the corn snake.

<span class="mw-page-title-main">Trinket snake</span> Species of snake

The trinket snake, also known commonly as the common trinket snake, is a species of nonvenomous constricting snake in the family Colubridae. The species is native to southern Central Asia.

<span class="mw-page-title-main">Mandarin rat snake</span> Species of snake

The mandarin rat snake is a species of nonvenomous colubrid snake endemic to Asia. It is closely related to Euprepiophis conspicillata, the Japanese forest rat snake. Mandarin rat snakes are one of the most popular rat snakes found in the pet trade.

<i>Pantherophis vulpinus</i> Species of snake

Pantherophis vulpinus, commonly known as the foxsnake or the eastern fox snake, is a species of nonvenomous rat snake in the family Colubridae. The species is native to North America.

<span class="mw-page-title-main">Eastern racer</span> Species of snake

The eastern racer, or North American racer, is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America and Central America. Eleven subspecies, including the nominotypical subspecies, are recognized, which as a group are commonly referred to as the eastern racers. The species is monotypic in the genus Coluber.

<span class="mw-page-title-main">Texas rat snake</span> Subspecies of snake

The Texas rat snake is a subspecies of the black rat snake, a nonvenomous colubrid. It is found in the United States, primarily within the state of Texas, but its range extends into Louisiana, Arkansas and Oklahoma. It intergrades with other subspecies of Elaphe obsoleta, so exact range boundaries are impossible to distinguish. The epithet lindheimeri is to honor the German-American naturalist Ferdinand Jacob Lindheimer, who collected the first specimen in New Braunfels, Texas.

<i>Pantherophis emoryi</i> Species of snake

Pantherophis emoryi, commonly known as the Great Plains rat snake, is a species of nonvenomous rat snake in the family Colubridae. The species is native to the central part of the United States, from Missouri to Nebraska, to Colorado, south to Texas, and into northern Mexico.

<i>Pantherophis bairdi</i> Species of snake

Pantherophis bairdi is a species of harmless snake in the family Colubridae. The species is native to the southwestern United States and adjacent northeastern Mexico. No subspecies are recognized as being valid.

<span class="mw-page-title-main">Japanese rat snake</span> Species of snake

The Japanese rat snake is a medium-sized colubrid snake found throughout the Japanese archipelago as well as on the Russian-administered Kunashir Island. In Japanese it is known as the aodaishō or "blue general". It is non-venomous. It is hunted by eagles and tanukis.

<i>Elaphe schrenckii</i> Species of snake

Elaphe schrenckii is a species of nonvenomous snake in the family Colubridae. The species is indigenous to Northeast Asia.

<i>Elaphe carinata</i> Species of snake

Elaphe carinata, the king ratsnake, is a species of Colubrid snake found in Southeast and East Asia.

Slowinski's corn snake is a subspecies of nonvenomous snake in the family Colubridae. The subspecies is indigenous to Louisiana, eastern Texas, and Arkansas.

<i>Coelognathus</i> Genus of snakes

Coelognathus is a genus of seven species of rat snakes in the subfamily Colubrinae of the family Colubridae. The species, which are native to South Asia and Southeast Asia, were formerly assigned to the genus Elaphe. Based on morphological evidence and protein similarities, in 2001, Helfenberger revalidated the name Coelognathus that had originally been proposed by Leopold Fitzinger in 1843. The distinction between Coelognathus and Elaphe was further supported by mitochondrial DNA sequence and additional morphological evidence in 2005.

<span class="mw-page-title-main">Four-lined snake</span> Species of snake

Elaphe quatuorlineata is a member of the family Colubridae. The four-lined snake is a non-venomous species and one of the largest of the European snakes.

<i>Pantherophis alleghaniensis</i> Species of snake

Pantherophis alleghaniensis, commonly called the eastern rat snake, is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America.

Caryospora is a genus of parasitic protozoa in the phylum Apicomplexa. The species in this genus infect birds and reptiles with the majority of described species infecting snakes. It is the third largest genus in the family Eimeriidae.

References

  1. 1 2 3 4 5 Bartlett, Patricia; Bartlett, R.D. (2006-05-26). Corn Snakes and Other Rat Snakes. Complete Pet Owner's Manual (2nd ed.). Hauppauge NY: Barron's Educational Series. ISBN   0-7641-3407-8.
  2. 1 2 Burton, M.; Burton, R. (1969). "Rat Snake". The International Wildlife Encyclopedia. (pp. 1909–1910). New York: Marshall Cavendish Corp.
  3. 1 2 3 Wright, A.H.; Wright, A.A. (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates, a Division of Cornell University Press. 1,105 pp. (in 2 volumes). ("Rat Snakes", p. 209; Elaphe emoryi, longevity, p. 220).
  4. ↑ Conant, Roger (1975). A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Houghton Mifflin. Boston. xviii + 429 pp. + Plates 1–48. ISBN   0-395-19979-4 (hardcover), ISBN   0-395-19977-8 (paperback).
  5. 1 2 Wernert, S.J. (1982). Reptiles. Reader's Digest North American Wild Life. Pleasantville, New York: Reader's Digest. p. 174.
  6. ↑ Evans, A.V.; Garrison, R.W.; Schlager, N.; Hutchins, M.; Murphy, J. (2004). Vol 7. Grzimeks' Animal life Encyclopedia (2nd ed., p. 467). Detroit: Thomson-Gale.
  7. ↑ "Rat snakes – lifecycle, predation, diet, bites, hibernation, pictures and videos." Ratsnake.org. (2010-09-23).
  8. 1 2 3 Barnard, S.M.; Hollinger, T.G.; Romaine, T.A. (1979). "Growth and Food Consumption in the Corn Snake, Elaphe guttata guttata". Copeia. 4 (4): 739–741. doi:10.2307/1443884. JSTOR   1443884.
  9. 1 2 George, L. (2002). Mating. Rat Snake (1 ed.), Mankato, Minnesota: Capstone Press, pp. 33–34, ISBN   0736809090.
  10. 1 2 Roots, C. (2006). Uncontrolled Hypothermia. Hibernation, Westport, Conn.: Greenwood Press, p. 88, ISBN   0313335443.
  11. ↑ Werler, J.E.; Dixon, J.R. (2000). 39. Texas snakes: identification, distribution, and natural history, p. 118, Austin: University of Texas Press, ISBN   0292791305.
  12. ↑ Knight, Rex; Korell, Sacha (1997). "Ratsnakes of the Genus Elaphe – Species." Ratsnakes of the Genus Elaphe – Introduction. OnlineHobbyist.com, Inc. (2010-09-22).
  13. 1 2 LeClere, Jeff (2005). Iowa Reptiles and Amphibians – Rat Snake – Elaphe obsoleta. HerpNet – Home. Web. 22 Sept. 2010.
  14. 1 2 Trepanowski, P. (2003). "Elaphe obsoleta", Animal Diversity Web. Accessed September 22, 2010.
  15. ↑ Bateman, G. (1981). Snakes. The Encyclopedia of Reptiles and Amphibians (pp. 115, 117).
  16. ↑ Ziesmann, Jurgen. (2010). Vertebrate Biology Lecture Notes: Reptiles 09. Azusa Pacific University
  17. ↑ Huang, Song (2012). "A New Species of the Genus Elaphe (Squamata: Colubridae) from Zoige County, Sichuan, China" (PDF). Asian Herpetological Research. 3 (1): 38–45. doi:10.3724/SP.J.1245.2012.00038.
  18. ↑ Genus Elaphe at The Reptile Database www.reptile-database.org.


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