Difference between revisions of "Python" - New World Encyclopedia

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{{Taxobox
 
{{Taxobox
 
| name = Pythonidae
 
| name = Pythonidae
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* Pythoninae - Boulenger, 1890
 
* Pythoninae - Boulenger, 1890
 
* Pythonini - Underwood & Stimson, 1990
 
* Pythonini - Underwood & Stimson, 1990
* Moreliini - Underwood & Stimson, 1990<ref name="McD99">McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).</ref>
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* Moreliini - Underwood & Stimson, 1990<ref name="McD99">R. W. McDiarmid, J. A. Campbell, and T. Touré. ''Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1.'' (Herpetologists' League 1999). ISBN 1893777006 (series). ISBN 1893777014 (volume).</ref>
 
}}
 
}}
'''Python''' is the common name for any of the non-[[venomous]] constricting [[snake]]s comprising the [[snake]] family '''Pythonidae''', characterized by  
+
'''Python''' is the common name for any of the non-[[venomous]] constricting [[snake]]s comprising the [[Old World]] family '''Pythonidae''', characterized by paired [[lung]]s, cloacal spurs, teeth on the premaxilla bone, and production of eggs rather than live birth. Found in [[Africa]], [[Asia]], [[Australia]], and islands of the [[South Pacific]], members of this family include some of the largest snakes in the world. There are about 32 species distributed among eight [[genera]], including one genus with the name '''''Python''''' with seven species.
  
 +
Pythons are similar to the [[anaconda]]s comprising the genus ''Eunectes'' within the [[Boidae]] (boa) family of snakes. Both have two lungs and are constrictors that suffocate their prey by wrapping around it. However, in addition to various physical differences, pythons are found in the [[Old World]] and anacondas in the [[New World]]. However, pythons are similar enough to members of Boidae that some authorities actually place pythons as a subfamily, Pythoninae, within the [[boa]] family.
  
The '''Pythonidae''' are a [[Family (biology)|family]] of non-[[venomous]] [[snake]]s found in [[Africa]], [[Asia]] and [[Australia]]. Among its members are some of the largest snakes in the world. Eight [[Genus|genera]] and 26 [[species]] are currently recognized.<ref name="ITIS">{{ITIS|ID=563893|taxon=Pythonidae|year=2007|date=15 September}}</ref>
+
While pythons are feared for their ability to kill humans, and such behavior, while rare, is known, they also provide important functions for people. Historically, they have served as a source of food for [[indigenous people]]s and their skins have been traded as a valued commodity, to be made into shoes or handbags. They have been used in traditional medicine and revered in some cultures, and captive breed pythons are used in a large market for pets. Ecologically, they help to control prey populations and small species and young are themselves preyed upon by various [[reptile]]s ([[monitor lizard]]s, [[crocodile]]s), [[birds of prey]], and [[mammal]]s ([[felid]]s).
  
 +
==Overview and description==
 +
[[Image:Greentreepython.jpg|left|240px|thumb|Green tree python, ''[[Morelia viridis]]'']]
  
'''''Python''''' [Gr. Πύθων] is a [[genus]] of non-venomous [[Pythonidae|python]]s found in [[Africa]] and [[Asia]]. Currently, 7 [[species]] are recognized.<ref name="ITIS"/>
+
Pythons are similar in appearance and closely related to [[boa]]s, the common name for snakes comprising the family [[Boidae]]. Both boas and pythons are considered to be primitive snakes, and both are constrictors. Both also have two fully functional lungs (most snakes have one lung) and have remnants of hind legs and pelvic bones (SDZ 2007). Pythons also share a cloacal spur, elliptical pupils, and pitted lip scales associated with thermoreception (Barker and Barker 2004). In some taxonomies, pythons are placed in the subfamily Pythoninae wihtin Boidae.  
  
:Like the related and similarly appearing [[python]]s, they have two lungs and are constrictors that suffocate their prey by wrapping around it; however, in addition to various physical differences, pythons are found in the [[Old World]] and anacondas in the [[New World]] (SDZ 2007). Anacondas comprise a [[genus]] of boas (one of twelve genera of boas, depending on the [[taxonomy|taxonomic]] scheme employed). Boas are a type of non-venomous [[snake]]s that are members of the Boidae family.  
+
The Pythonidae are distinguished from the family Boidae by a number of physical characters. For one, most adult pythons have [[teeth]] on the [[premaxilla]], a small bone at the very front and center of the upper jaw. The premaxilla of boas is without teeth. In addition, in pythons the prefrontal bone is in contact with the supraorbital bone, a small bone at the top of the eye socket; in boas, only one group has a supraorbital bone and it is not in contact with the prefrontal. Python labial pits also are located in the centers of the lip scales, but in those boas with labila pits they are located between the lip scales. Furthermore, while most boas produce live young, pythons produce [[Egg (biology)|eggs]] (Barker and Barker 2004).
 
 
==Overview and description==
 
[[Image:Greentreepython.jpg|left|240px|thumb|Green tree python, ''[[Morelia viridis]]'']] Adults range in size from 0.5 to 9.75 [[meter]]s (1.5 to 32 [[foot (length)|feet]]) in length. One species, ''[[Python reticulatus]]'', the reticulated python, is probably the world's longest snake.
 
  
Boas are similar in appearance and closely related to pythons, the common name for a group of non-venomous constricting snakes comprising the family Pythonidae. Both boas and pythons are considered to be primitive snakes, and both are constrictors. Both also have two lungs (most snakes have one lung) and have remnants of hind legs and pelvic bones (SDZ 2007). They are similar enough that some authorities actually place pythons as a subfamily (Pythoninae) within the boa family. Pythons are distinguishable from boas in that they have teeth on the premaxilla, a small bone at the very front and center of the upper jaw. Furthermore, while most boas produce live young, pythons produce [[Egg (biology)|eggs]].
+
Pythons are medium to large size snakes, ranging from 0.5 to 10.1 meters (1.5-33 feet) in length, and a weight of 0.14 to 145 kilograms (0.3 to 320 pounds) (Barker and Barker 2004). One species, ''[[Python reticulatus]],'' the reticulated python, is probably the world's longest snake, with largest commonly cited maximum a specimen being 10.1 meters (33 feet). Two other species that are large are the Indian python, ''Python molurus,'' which ranges from 5.8 to 6.7 meters (19-22 feet), and the African rock python, ''Python sebae,'' which ranges from 8.5 to 9.8 meters (28-32 feet) (Barker and Barker 2004).  
  
The Pythonidae are distinguished from the family [[Boidae]] (boas) by the fact that they have [[teeth]] on the [[premaxilla]]: a small [[bone]] at the very front and center of the upper [[jaw]]. Most species have rows of heat-sensing organs between the [[sublabial scales]]: [[infrared sensing in snakes|labial pit]]s. Although not as well developed as the [[loreal pit]]s of the subfamily [[Crotalinae]] (pitvipers), these organs enable the snakes to detect objects that are hotter than the surrounding environment, and enable hunting to take place in total darkness, such as inside caves.
+
Most python species have rows of heat-sensing organs between the [[sublabial scales]]: [[infrared sensing in snakes|labial pit]]s. Although not as well developed as the [[loreal pit]]s of the subfamily [[Crotalinae]] (pitvipers), these organs enable the snakes to detect objects that are hotter than the surrounding environment, and enable hunting to take place in total darkness, such as inside [[cave]]s.
  
 
Some species exhibit vestigial bones of the pelvis and rear legs, which are externally apparent in the form of a pair of [[anal spurs]] on each side of the [[cloaca]]. These spurs are larger in males than females, and are used by the male to grip and/or stimulate the female during copulation. Males of certain species occasionally cause spur related injuries to each other during territorial combat, and though more likely to be incidental than intentional, some captured specimens have shown multiple episodes of scarring from such injuries.
 
Some species exhibit vestigial bones of the pelvis and rear legs, which are externally apparent in the form of a pair of [[anal spurs]] on each side of the [[cloaca]]. These spurs are larger in males than females, and are used by the male to grip and/or stimulate the female during copulation. Males of certain species occasionally cause spur related injuries to each other during territorial combat, and though more likely to be incidental than intentional, some captured specimens have shown multiple episodes of scarring from such injuries.
  
Color patterns vary from striking to nondescript brown or green. It usually reflects appropriate [[camouflage]] for the native habitat. Even within a given species, there may be enormous differences in coloration and pattern in different parts of the geographic range.
+
Color patterns vary from striking to nondescript brown or green. It usually reflects appropriate [[camouflage]] for the native habitat. Even within a given species, there may be enormous differences in coloration and pattern in different parts of the geographic range. A color change as the snakes mature is common to most species (Barker and Barker 2004). Some species, such a ''Morelia oenpelliensis'' and ''Apodora papuana,'' have the ability to change color dramatically. Some display iridescent colors, such as the ringed python, ''Bothrochilus boa,'' and the white-lipped python, ''Leiopython albertisii'' (Barker and Barker 2004).
 
 
==Geographic range==
 
Found in subsaharan [[Africa]], peninsular [[India]], [[Myanmar]], southern [[China]], [[Southeast Asia]] and from the [[Philippines]] southeast through [[Indonesia]] to [[New Guinea]] and [[Australia]].<ref name="McD99"/>
 
 
 
In the [[United States]], a population of Burmese pythons, ''[[Python molurus bivittatus]]'', has existed as an invasive species in the [[Everglades National Park]] since the late 1990s, which has damaged the local ecosystem. More than 300 have been removed. They are not native to the south Floridian marshlands, but have been deposited there by pet owners who no longer wished to care for them and also did not want to euthanize them. Scientists believe that the snakes are a grave threat to nearly every species of animal in the Everglades, including [[alligators]]. There have been several accounts of python versus alligator encounters there, including one in autumn 2005 between a 13-foot (4&nbsp;m) python and a six-foot (1.8&nbsp;m) alligator that proved fatal for both. The two were found with the alligator's body protruding from a tear in the snake's body. <ref name="NGeo">[http://news.nationalgeographic.com/news/2004/06/0603_040603_invasivespecies.html Huge, Freed Pet Pythons Invade Florida Everglades] at [http://news.nationalgeographic.com/ http://news.nationalgeographic.com/news/ National Geographic News]. Accessed [[16 September]] [[2007]].</ref>
 
 
 
==Conservation==
 
Many species have been hunted aggressively, which has decimated some, such as the Indian python, ''[[Python molurus]]''.
 
  
==Behavior==
+
==Distribution and habitat==
[[Image:Blackheaded python2.jpg|right|240px|thumb|Black-headed python,<br/>''[[Aspidites melanocephalus]]'']] Most members of this family are [[ambush predator]]s, in that they typically remain motionless in a camouflaged position and then strike suddenly at passing prey. They will generally not attack humans unless startled or provoked, although females protecting their eggs can be aggressive. Large adult specimens can kill people. Unsuspecting children can and have been preyed upon and swallowed whole after being suffocated. Reports of attacks on human beings were once more common in South and Southeast Asia, but are now quite rare.
+
[[Image:Leiopython albertisii.jpg|thumb|right|240px|White-lipped python ''(Leiopython albertisii)'']]
 +
Pythons are found in sub-Saharan [[Africa]], peninsular [[India]], [[Myanmar]], southern [[China]], [[Southeast Asia]], and from the [[Philippines]] southeast through [[Indonesia]] to [[New Guinea]] and [[Australia]] (McDiarmid 1999). Pythons inhabit a wide range of habitats, including [[wetland]]s, open forest, harsh desert, [[rainforest]], rocky slopes, and savanna (Barker and Barker 2004). Water pythons ''(Liasis fuscus)'' are essentially aquatic for about six months of the year in the [[monsoon]]-flooded plains of northern [[Australia]], while the green python ''(Morelia viridis)'' is adapted to an arboreal life in [[forest]]s.  
  
==Feeding==
+
In the [[United States]], a population of Burmese pythons, ''[[Python molurus bivittatus]],'' has existed as an [[invasive species]] in the [[Everglades National Park]] since the late 1990s, which has damaged the local [[ecosystem]]. More than 300 have been removed. They are not native to the south Floridian marshlands, but have been deposited there by pet owners who no longer wished to care for them and also did not want to euthanize them. Scientists believe that the snakes are a grave threat to nearly every species of animal in the Everglades, including [[alligator]]s. There have been several accounts of python versus alligator encounters there, including one in autumn 2005 between a 13-foot (4&nbsp;m) python and a six-foot (1.8&nbsp;m) alligator that proved fatal for both. The two were found with the alligator's body protruding from a tear in the snake's body (Lovgren 2004).  
Prey is killed by a process known as ''[[constriction]]''; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure to prevent it from inhaling, the prey eventually succumbs due to [[asphyxia]]tion. It has recently been suggested that the pressures produced during constriction cause cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed.
 
  
Larger specimens usually eat animals about the size of a house cat, but larger food items are not unknown: some large Asian species have been known to take down adult [[deer]], and the African rock python, ''[[Python sebae]]'', has been known to eat [[gazelle]]. Prey is swallowed whole, and may take anywhere from several days or even weeks to fully digest.  Despite their intimidating size and muscular power, they are generally not dangerous to humans.
+
==Behavior, feeding, and reproduction==
 +
[[Image:Blackheaded python2.jpg|right|240px|thumb|Black-headed python,<br/>''[[Aspidites melanocephalus]]'']]
 +
Most members of Pythonidae are [[ambush predator]]s, in that they typically remain motionless in a camouflaged position and then strike suddenly at passing prey. Larger specimens usually eat animals about the size of a house cat, but larger food items are not unknown: some large Asian species have been known to take down adult [[deer]], and the African rock python, ''[[Python sebae]],'' has been known to eat [[gazelle]]. Prey is swallowed whole, and may take anywhere from several days or even weeks to fully digest.  
  
Contrary to popular belief, even the larger species, such as the reticulated python, ''[[Python reticulatus|P. reticulatus]]'', do not crush their prey to death; in fact, prey is not even noticeably deformed before it is swallowed. The speed with which the coils are applied is impressive and the force they exert may be significant, but death is caused by suffocation, with the victim not being able to move its ribs in order to breathe while it is being constricted.<ref name="Meh87">Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.</ref><ref name="Sti74">Stidworthy J. 1974. Snakes of the World. Grosset & Dunlap Inc. 160 pp. ISBN 0-448-11856-4.</ref><ref name="Car63">Carr A. 1963. The Reptiles. Life Nature Library. Time-Life Books, New York. 192 pp. LCCCN 63-12781.</ref>
+
Prey is killed by a process known as ''[[constriction]]''; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure to prevent it from inhaling, the prey eventually succumbs due to [[asphyxia]]tion. Contrary to popular belief, even the larger species, such as the reticulated python, ''[[Python reticulatus|P. reticulatus]],'' do not crush their prey to death; in fact, prey is not even noticeably deformed before it is swallowed. The speed with which the coils are applied is impressive and the force they exert may be significant, but death is caused by suffocation, with the victim not being able to move its ribs in order to breathe while it is being constricted (Mehrtens 1987; Stidworthy 1974; Carr 1963). It has recently been suggested that the pressures produced during constriction cause cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed.
  
==Reproduction==
+
Despite their intimidating size and muscular power, pythons generally are not dangerous to humans. They will generally not attack humans unless startled or provoked, although females protecting their eggs can be aggressive. Large adult specimens can kill people. Unsuspecting children can and have been preyed upon and swallowed whole after being suffocated. Reports of attacks on human beings were once more common in South and Southeast Asia, but are now quite rare.
Females lay eggs ([[oviparous]]). This sets them apart from the family [[Boidae]] (boas), most of which bear live young ([[ovoviviparous]]). After they lay their eggs, females will typically incubate them until they hatch. This is achieved by causing the muscles to "shiver", which raises the temperature of the body to a certain degree, and thus that of the eggs. Keeping the eggs at a constant temperature is essential for healthy embryo development. During the incubation period, females will not eat and only leave to bask in order to raise their body temperature.
 
  
==Captivity==
+
Females lay eggs ([[oviparous]]). This sets them apart from the family [[Boidae]] (boas), most of which bear live young ([[ovoviviparous]]). After they lay their eggs, females will typically incubate them until they hatch. This is achieved by causing the muscles to "shiver," which raises the temperature of the body to a certain degree, and thus that of the eggs. Keeping the eggs at a constant temperature is essential for healthy embryo development. During the incubation period, females will not eat and only leave to bask in order to raise their body temperature.
Most species in this family are available in the exotic pet trade. However, caution must be exercised with the larger species as they can be dangerous; cases of large specimens killing their owners have been documented.<ref name="Anapsid">[http://www.anapsid.org/coloburm.html The Keeping of Large Pythons] at [http://www.anapsid.org/ Anapsid]. Accessed [[16 September]] [[2007]].</ref>
 
  
 
==Genera==
 
==Genera==
 
{|cellspacing=0 cellpadding=2 border=1 style="border-collapse: collapse;"
 
{|cellspacing=0 cellpadding=2 border=1 style="border-collapse: collapse;"
!bgcolor="#f0f0f0"|Genus<ref name="ITIS"/>
+
!bgcolor="#f0f0f0"|Genus<ref name="ITIS">Integrated Taxonomic Information System (ITIS), "[http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=563893 Pythonidae  Fitzinger, 1826]," ''ITIS Taxonomic Serial No.: 563893'' (2006). Retrieved January 4, 2009.</ref>
 
!bgcolor="#f0f0f0"|Taxon author<ref name="ITIS"/>
 
!bgcolor="#f0f0f0"|Taxon author<ref name="ITIS"/>
 
!bgcolor="#f0f0f0"|Species<ref name="ITIS"/>
 
!bgcolor="#f0f0f0"|Species<ref name="ITIS"/>
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|align="center"|0
 
|align="center"|0
 
|Bismark ringed python
 
|Bismark ringed python
|The islands of the [[Bismark Archipelago]], including [[Umboi Island|Umboi]], [[New Britain]], Gasmata (off the southern coast), [[Duke of York Island, Papua New Guinea|Duke of York]] and nearby Mioko, [[New Ireland (island)|New Ireland]] and nearby Tatau (off the east coast), the [[New Hanover Island]]s and [[Nissan Island]].
+
|The islands of the [[Bismark Archipelago]], including [[Umboi Island|Umboi]], [[New Britain]], Gasmata (off the southern coast), [[Duke of York Island, Papua New Guinea|Duke of York]] and nearby Mioko, [[New Ireland (island)|New Ireland]] and nearby Tatau (off the east coast), the [[New Hanover Island]]s, and [[Nissan Island]].
 
|-
 
|-
 
|''[[Leiopython]]''
 
|''[[Leiopython]]''
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|-
 
|-
 
|}
 
|}
''*) Not including the nominate subspecies.''<br>
+
''*) Not including the nominate subspecies.''<br/>
 
<font size="-1"><sup>T</sup></font>) [[Type genus]].<ref name="McD99"/>
 
<font size="-1"><sup>T</sup></font>) [[Type genus]].<ref name="McD99"/>
  
==Taxonomy==
+
==Conservation==
Pythons are more related to [[Boidae|boas]] than to any other snake-family. [[George Albert Boulenger|Boulenger]] (1890) considered this group to be a subfamily (Pythoninae) of the family [[Boidae]] (boas).<ref name="McD99"/>
+
Many species have been hunted aggressively, which has decimated some, such as the Indian python, ''[[Python molurus]].'' All pythons are listed as Vulnerable by the [[IUCN]] and one subspecies of the Indian python ''(P. m. molurus)'' is listed as Endangered (Barker and Barker 2004).
  
 
==Gallery==
 
==Gallery==
Line 150: Line 143:
 
Image:Morelia viridis.jpg|Green tree python,<br/>''[[Morelia viridis]]''
 
Image:Morelia viridis.jpg|Green tree python,<br/>''[[Morelia viridis]]''
 
Image:Burmese Python 02.jpg|Albino Burmese python,<br/>''[[Python molurus bivittatus]]''
 
Image:Burmese Python 02.jpg|Albino Burmese python,<br/>''[[Python molurus bivittatus]]''
Image:Python breitensteini .jpg|Borneo short-tailed python,<br/>''[[Python curtus breitensteini]]''
 
Image:Leiopython albertisii.jpgWhite-lipped python,<br/>''Leiopython albertisii''
 
 
</gallery>
 
</gallery>
  
==See also==
+
==Notes==
* [[List of pythonid species and subspecies]]
+
<references/>
* {{c|Pythonidae by common name}}
 
* {{c|Pythonidae by taxonomic synonyms}}
 
* [[List of snakes]], overview of all snake families and genera.
 
  
 
==References==
 
==References==
{{Reflist}}
 
  
 +
* Carr A. 1963. ''The Reptiles''. Life Nature Library. New York: Time-Life Books.
 +
 +
* Integrated Taxonomic Information System (ITIS). 2004. [http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=563893 Pythonidae  Fitzinger, 1826] ''ITIS Taxonomic Serial No.: 563893''. Retrieved January 4, 2009.
 +
 +
* Lovgren, S. 2004. [http://news.nationalgeographic.com/news/2004/06/0603_040603_invasivespecies.html Huge, freed pet pythons invade Florida everglades]. ''National Geographic News'' June 3, 2004. Retrieved January 4, 2009.
 +
 +
* McDiarmid, R. W., J. A. Campbell, and T. Touré. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference'', vol. 1. Herpetologists' League. ISBN 1893777006 (series). ISBN 1893777014 (volume).
 +
 +
* Mehrtens, J. M. 1987. ''Living Snakes of the World in Color''. New York: Sterling Publishers. ISBN 080696460X.
  
* San Diego Zoo (SDZ). 2007. [http://www.sandiegozoo.org/animalbytes/t-boa.html Reptiles: Boa]. ''San Diego Zoo's Animal Bytes.'' Retrieved August 22,2007.
+
* San Diego Zoo (SDZ). 2007. [http://www.sandiegozoo.org/animalbytes/t-boa.html Reptiles: Boa]. ''San Diego Zoo's Animal Bytes.'' Retrieved January 4, 2009.
  
==External links==
+
* Stidworthy J. 1974. ''Snakes of the World''. Grosset & Dunlap. ISBN 0448118564.
{{wikispecies}}
 
{{Commons}}
 
* {{NRDB family|page=boidae.php|family=Boidae|date=3 November|year=2008}}
 
* [http://www.answers.com/topic/pythons-pythonidae-biological-family Pythons (Pythonidae)] at [http://www.answers.com/ Answers.com]. Accessed [[3 November]] [[2008]].
 
  
 
{{Snake families}}
 
{{Snake families}}

Latest revision as of 15:06, 2 July 2022

Pythonidae
Indian python, Python molurus
Indian python, Python molurus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Infraorder: Alethinophidia
Family: Pythonidae
Fitzinger, 1826
Synonyms
  • Pythonoidea - Fitzinger, 1826
  • Pythonoidei - Eichwald, 1831
  • Holodonta - Müller, 1832
  • Pythonina - Bonaparte, 1840
  • Pythophes - Fitzinger, 1843
  • Pythoniens - A.M.C. Duméril & Bibron, 1844
  • Holodontes - A.M.C. Duméril & Bibron, 1844
  • Pythonides - A.M.C. Duméril & Bibron, 1844
  • Pythones - Cope, 1861
  • Pythonidae - Cope, 1864
  • Peropodes - Meyer, 1874
  • Chondropythonina - Boulenger, 1879
  • Pythoninae - Boulenger, 1890
  • Pythonini - Underwood & Stimson, 1990
  • Moreliini - Underwood & Stimson, 1990[1]

Python is the common name for any of the non-venomous constricting snakes comprising the Old World family Pythonidae, characterized by paired lungs, cloacal spurs, teeth on the premaxilla bone, and production of eggs rather than live birth. Found in Africa, Asia, Australia, and islands of the South Pacific, members of this family include some of the largest snakes in the world. There are about 32 species distributed among eight genera, including one genus with the name Python with seven species.

Pythons are similar to the anacondas comprising the genus Eunectes within the Boidae (boa) family of snakes. Both have two lungs and are constrictors that suffocate their prey by wrapping around it. However, in addition to various physical differences, pythons are found in the Old World and anacondas in the New World. However, pythons are similar enough to members of Boidae that some authorities actually place pythons as a subfamily, Pythoninae, within the boa family.

While pythons are feared for their ability to kill humans, and such behavior, while rare, is known, they also provide important functions for people. Historically, they have served as a source of food for indigenous peoples and their skins have been traded as a valued commodity, to be made into shoes or handbags. They have been used in traditional medicine and revered in some cultures, and captive breed pythons are used in a large market for pets. Ecologically, they help to control prey populations and small species and young are themselves preyed upon by various reptiles (monitor lizards, crocodiles), birds of prey, and mammals (felids).

Overview and description

Green tree python, Morelia viridis

Pythons are similar in appearance and closely related to boas, the common name for snakes comprising the family Boidae. Both boas and pythons are considered to be primitive snakes, and both are constrictors. Both also have two fully functional lungs (most snakes have one lung) and have remnants of hind legs and pelvic bones (SDZ 2007). Pythons also share a cloacal spur, elliptical pupils, and pitted lip scales associated with thermoreception (Barker and Barker 2004). In some taxonomies, pythons are placed in the subfamily Pythoninae wihtin Boidae.

The Pythonidae are distinguished from the family Boidae by a number of physical characters. For one, most adult pythons have teeth on the premaxilla, a small bone at the very front and center of the upper jaw. The premaxilla of boas is without teeth. In addition, in pythons the prefrontal bone is in contact with the supraorbital bone, a small bone at the top of the eye socket; in boas, only one group has a supraorbital bone and it is not in contact with the prefrontal. Python labial pits also are located in the centers of the lip scales, but in those boas with labila pits they are located between the lip scales. Furthermore, while most boas produce live young, pythons produce eggs (Barker and Barker 2004).

Pythons are medium to large size snakes, ranging from 0.5 to 10.1 meters (1.5-33 feet) in length, and a weight of 0.14 to 145 kilograms (0.3 to 320 pounds) (Barker and Barker 2004). One species, Python reticulatus, the reticulated python, is probably the world's longest snake, with largest commonly cited maximum a specimen being 10.1 meters (33 feet). Two other species that are large are the Indian python, Python molurus, which ranges from 5.8 to 6.7 meters (19-22 feet), and the African rock python, Python sebae, which ranges from 8.5 to 9.8 meters (28-32 feet) (Barker and Barker 2004).

Most python species have rows of heat-sensing organs between the sublabial scales: labial pits. Although not as well developed as the loreal pits of the subfamily Crotalinae (pitvipers), these organs enable the snakes to detect objects that are hotter than the surrounding environment, and enable hunting to take place in total darkness, such as inside caves.

Some species exhibit vestigial bones of the pelvis and rear legs, which are externally apparent in the form of a pair of anal spurs on each side of the cloaca. These spurs are larger in males than females, and are used by the male to grip and/or stimulate the female during copulation. Males of certain species occasionally cause spur related injuries to each other during territorial combat, and though more likely to be incidental than intentional, some captured specimens have shown multiple episodes of scarring from such injuries.

Color patterns vary from striking to nondescript brown or green. It usually reflects appropriate camouflage for the native habitat. Even within a given species, there may be enormous differences in coloration and pattern in different parts of the geographic range. A color change as the snakes mature is common to most species (Barker and Barker 2004). Some species, such a Morelia oenpelliensis and Apodora papuana, have the ability to change color dramatically. Some display iridescent colors, such as the ringed python, Bothrochilus boa, and the white-lipped python, Leiopython albertisii (Barker and Barker 2004).

Distribution and habitat

White-lipped python (Leiopython albertisii)

Pythons are found in sub-Saharan Africa, peninsular India, Myanmar, southern China, Southeast Asia, and from the Philippines southeast through Indonesia to New Guinea and Australia (McDiarmid 1999). Pythons inhabit a wide range of habitats, including wetlands, open forest, harsh desert, rainforest, rocky slopes, and savanna (Barker and Barker 2004). Water pythons (Liasis fuscus) are essentially aquatic for about six months of the year in the monsoon-flooded plains of northern Australia, while the green python (Morelia viridis) is adapted to an arboreal life in forests.

In the United States, a population of Burmese pythons, Python molurus bivittatus, has existed as an invasive species in the Everglades National Park since the late 1990s, which has damaged the local ecosystem. More than 300 have been removed. They are not native to the south Floridian marshlands, but have been deposited there by pet owners who no longer wished to care for them and also did not want to euthanize them. Scientists believe that the snakes are a grave threat to nearly every species of animal in the Everglades, including alligators. There have been several accounts of python versus alligator encounters there, including one in autumn 2005 between a 13-foot (4 m) python and a six-foot (1.8 m) alligator that proved fatal for both. The two were found with the alligator's body protruding from a tear in the snake's body (Lovgren 2004).

Behavior, feeding, and reproduction

Black-headed python,
Aspidites melanocephalus

Most members of Pythonidae are ambush predators, in that they typically remain motionless in a camouflaged position and then strike suddenly at passing prey. Larger specimens usually eat animals about the size of a house cat, but larger food items are not unknown: some large Asian species have been known to take down adult deer, and the African rock python, Python sebae, has been known to eat gazelle. Prey is swallowed whole, and may take anywhere from several days or even weeks to fully digest.

Prey is killed by a process known as constriction; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure to prevent it from inhaling, the prey eventually succumbs due to asphyxiation. Contrary to popular belief, even the larger species, such as the reticulated python, P. reticulatus, do not crush their prey to death; in fact, prey is not even noticeably deformed before it is swallowed. The speed with which the coils are applied is impressive and the force they exert may be significant, but death is caused by suffocation, with the victim not being able to move its ribs in order to breathe while it is being constricted (Mehrtens 1987; Stidworthy 1974; Carr 1963). It has recently been suggested that the pressures produced during constriction cause cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed.

Despite their intimidating size and muscular power, pythons generally are not dangerous to humans. They will generally not attack humans unless startled or provoked, although females protecting their eggs can be aggressive. Large adult specimens can kill people. Unsuspecting children can and have been preyed upon and swallowed whole after being suffocated. Reports of attacks on human beings were once more common in South and Southeast Asia, but are now quite rare.

Females lay eggs (oviparous). This sets them apart from the family Boidae (boas), most of which bear live young (ovoviviparous). After they lay their eggs, females will typically incubate them until they hatch. This is achieved by causing the muscles to "shiver," which raises the temperature of the body to a certain degree, and thus that of the eggs. Keeping the eggs at a constant temperature is essential for healthy embryo development. During the incubation period, females will not eat and only leave to bask in order to raise their body temperature.

Genera

Genus[2] Taxon author[2] Species[2] Subsp.*[2] Common name Geographic range[1]
Antaresia Wells & Wellington, 1984 4 0 Australia in arid and tropical regions.
Apodora Kluge, 1993 1 0 Papuan python Most of New Guinea, from Misool to Fergusson Island.
Aspidites Peters, 1877 2 0 Australia except in the south of the country.
Bothrochilus Fitzinger, 1843 1 0 Bismark ringed python The islands of the Bismark Archipelago, including Umboi, New Britain, Gasmata (off the southern coast), Duke of York and nearby Mioko, New Ireland and nearby Tatau (off the east coast), the New Hanover Islands, and Nissan Island.
Leiopython Hubrecht, 1879 1 0 D'Albert's water python Most of New Guinea (below 1200 m), including the islands of Salawati and Biak, Normanby, Mussau, as well as a few islands in the Torres Strait.
Liasis Gray, 1842 3 2 Indonesia in the Lesser Sunda Islands, east through New Guinea and in northern and western Australia.
Morelia Gray, 1842 7 5 From Indonesia in the Maluku Islands, east through New Guinea, including the Bismark Archipelago and in Australia.
PythonT Daudin, 1803 7 4 Pythons Africa in the tropics south of the Sahara (not including southern and extreme southwestern Madagascar), Pakistan, India, Sri Lanka, the Nicobar Islands, Myanmar, Indochina, southern China, Hong Kong, Hainan, the Malayan region of Indonesia and the Philippines.

*) Not including the nominate subspecies.
T) Type genus.[1]

Conservation

Many species have been hunted aggressively, which has decimated some, such as the Indian python, Python molurus. All pythons are listed as Vulnerable by the IUCN and one subspecies of the Indian python (P. m. molurus) is listed as Endangered (Barker and Barker 2004).

Gallery

Notes

  1. 1.0 1.1 1.2 R. W. McDiarmid, J. A. Campbell, and T. Touré. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. (Herpetologists' League 1999). ISBN 1893777006 (series). ISBN 1893777014 (volume).
  2. 2.0 2.1 2.2 2.3 Integrated Taxonomic Information System (ITIS), "Pythonidae Fitzinger, 1826," ITIS Taxonomic Serial No.: 563893 (2006). Retrieved January 4, 2009.

References
ISBN links support NWE through referral fees

  • Carr A. 1963. The Reptiles. Life Nature Library. New York: Time-Life Books.
  • Integrated Taxonomic Information System (ITIS). 2004. Pythonidae Fitzinger, 1826 ITIS Taxonomic Serial No.: 563893. Retrieved January 4, 2009.
  • McDiarmid, R. W., J. A. Campbell, and T. Touré. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. ISBN 1893777006 (series). ISBN 1893777014 (volume).
  • Mehrtens, J. M. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. ISBN 080696460X.
  • San Diego Zoo (SDZ). 2007. Reptiles: Boa. San Diego Zoo's Animal Bytes. Retrieved January 4, 2009.
  • Stidworthy J. 1974. Snakes of the World. Grosset & Dunlap. ISBN 0448118564.

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