Reticulated python


The reticulated python is a species of snake in the family Pythonidae. The species is native to South Asia and Southeast Asia. It is the world's longest snake and listed as least concern on the IUCN Red List because of its wide distribution. In several range countries, it is hunted for its skin, for use in traditional medicine, and for sale as a pet.
It is an excellent swimmer, has been reported far out at sea and has colonized many small islands within its range.
It is among the three heaviest snakes. Like all pythons, it is a non-venomous constrictor. People have been killed by reticulated pythons.

Taxonomy

The reticulated python was first described in 1801 by German naturalist Johann Gottlob Theaenus Schneider, who described two zoological specimens held by the Göttingen Museum in 1801 that differed slightly in colour and pattern as separate species—Boa reticulata and Boa rhombeata. The specific name, reticulatus, is Latin meaning "net-like", or, and is a reference to the complex color pattern. The generic name Python was proposed by French naturalist François Marie Daudin in 1803. American zoologist Arnold G. Kluge performed a cladistics analysis on morphological characters and recovered the reticulated python lineage as sister to the genus Python, hence not requiring a new generic name in 1993.
In a 2004 genetics study using cytochrome b DNA, Robin Lawson and colleagues discovered the reticulated python as sister to Australo-Papuan pythons, rather than Python molurus and relatives. Raymond Hoser erected the genus for the reticulated python in 2004, naming it after German snake expert Stefan Broghammer, on the basis of dorsal patterns distinct from those of the genus Python, and a dark mid-dorsal line from the rear to the front of the head, and red or orange iris colour. In 2008, Lesley Rawlings and colleagues reanalysed Kruge's morphological data and combined it with genetic material, and found the reticulated clade to be an offshoot of the Australo-Papuan lineage as well. They adopted and redefined the genus name Broghammerus.
However, this and numerous other names by the same author were criticized by several authors, who proposed ignoring them for the purposes of nomenclature. Reynolds and colleagues subsequently described the genus Malayopython for this species and its sister species, the Timor python, calling the Timor python M. timoriensis. Hoser has since said that the Malayopython name is a junior synonym of Broghammerus, thus it should not be recognized by the International Code of Zoological Nomenclature. Neither of these proposed reclassifications has been recognized by the ITIS, but Malayopython has been recognized by a number of subsequent authors and the Reptile Database.

Subspecies

Three subspecies have been proposed:
The latter two are dwarf subspecies. Apparently, the population of the Sangihe Islands north of Sulawesi represents another such subspecies, which is basal to the P. r. reticulatus plus P. r. jampeanus clade, but it is not yet formally described.
The proposed subspecies M. r. "dalegibbonsi", M. r. "euanedwardsi", M. r. "haydnmacphiei", M. r. "neilsonnemani", M. r. "patrickcouperi", and M. r. "stuartbigmorei" have not found general acceptance.

Description

The reticulated python has smooth dorsal scales that are arranged in 69–79 rows at midbody. Deep pits occur on four anterior upper labials, on two or three anterior lower labials, and on five or six posterior lower labials.
The reticulated python is the largest snake native to Asia. More than a thousand wild reticulated pythons in southern Sumatra were studied and estimated to have a length range of and a weight range of. Reticulated pythons with lengths more than are rare, though according to the Guinness Book of World Records, it is the only extant snake to regularly exceed that length. One of the largest scientifically measured specimens, from Balikpapan, East Kalimantan, Indonesia, was measured under anesthesia at and weighed after not having eaten for nearly 3 months.
The specimen once widely accepted as the largest-ever "accurately" measured snake, that being Colossus, a specimen kept at the Highland Park Zoo in Pittsburgh, Pennsylvania, during the 1950s and early 1960s, with a peak reported length of from a measurement in November 1956, was later shown to have been substantially shorter than previously reported. When Colossus died on 14 April 1963, its body was deposited in the Carnegie Museum of Natural History. At that time, its skeleton was measured and found to be in total length, and the length of its fresh hide was measured as – both measurements being significantly shorter than what had been previously estimated in 1956. The hide tends to stretch from the skinning process, thus may be longer than the snake from which it came – e.g., by roughly 20–40% or more. The previous reports had been constructed by combining partial measurements with estimations to compensate for "kinks", since completely straightening an extremely large live python is virtually impossible. Because of these issues, a 2012 journal article concluded, "Colossus was neither the longest snake nor the heaviest snake ever maintained in captivity." Too large to be preserved with formaldehyde and then stored in alcohol, the specimen was instead prepared as a disarticulated skeleton. The hide was sent to a laboratory to be tanned, but it was either lost or destroyed, and now only the skull and selected vertebrae and ribs remain in the museum's collection. Considerable confusion exists in the literature over whether Colossus was male or female.
Numerous reports have been made of larger snakes, but since none of these was measured by a scientist nor any of the specimens deposited at a museum, they must be regarded as unproven and possibly erroneous. In spite of what has been, for many years, a standing offer of a large financial reward for a live, healthy snake over long by the New York Zoological Society, no attempt to claim this reward has ever been made.
The colour pattern is a complex geometric pattern that incorporates different colours. The back typically has a series of irregular diamond shapes flanked by smaller markings with light centers. In this species' wide geographic range, much variation of size, colour, and markings commonly occurs.
In zoo exhibits, the colour pattern may seem garish, but in a shadowy jungle environment amid fallen leaves and debris, it allows them to virtually disappear. Called disruptive colouration, it protects them from predators and helps them to catch their prey.
The huge size and attractive pattern of this snake has made it a favorite zoo exhibit, with several individuals claimed to be above in length and more than one claimed to be the largest in captivity. However, due to its huge size, immense strength, aggressive disposition, and the mobility of the skin relative to the body, it is very difficult to get exact length measurements of a living reticulated python, and weights are rarely indicative, as captive pythons are often obese. Claims made by zoos and animal parks are sometimes exaggerated, such as the claimed snake in Indonesia which was subsequently proven to be about long. For this reason, scientists do not accept the validity of length measurements unless performed on a dead or anesthetized snake that is later preserved in a museum collection or stored for scientific research.
A reticulated python kept in Kansas City, Missouri, named "Medusa" is considered by the Guinness Book of World Records to be the longest living snake ever kept in captivity. In 2011 it was reported to measure and weigh.
Dwarf forms of reticulated pythons also occur, from some islands northwest of Australia, and these are being selectively bred in captivity to be much smaller, resulting in animals often referred to as "super dwarfs". Adult super dwarf reticulated pythons are typically between in length.

Distribution and habitat

The reticulated python is found in South Asia from the Nicobar Islands, India, Bangladesh, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, and Singapore, east through Indonesia and the Indo-Australian Archipelago and the Philippines. The original description does not include a type locality. The type locality was restricted to "Java" by Brongersma.
Three subspecies have been proposed, but are not recognized in the Integrated Taxonomic Information System. The color and size can vary a great deal among the subspecies described. Geographical location is a good key to establishing the subspecies, as each one has a distinct geographical range.
The reticulated python lives in rain forests, woodlands, and nearby grasslands. It is also associated with rivers and is found in areas with nearby streams and lakes. An excellent swimmer, it has even been reported far out at sea and has consequently colonized many small islands within its range. During the early years of the 20th century, it is said to have been common even in busy parts of Bangkok, sometimes eating domestic animals.

Behaviour and ecology

Diet

As with all pythons, the reticulated python is an ambush hunter, usually waiting until prey wanders within strike range before seizing it in its coils and killing by constriction. Its natural diet includes mammals and occasionally birds. Small specimens up to long eat mainly rodents such as rats, whereas larger individuals switch to prey such as small Indian civet and binturong, primates, and pigs weighing more than. As a rule, the reticulated python seems able to swallow prey up to one-quarter its own length and up to its own weight. Near human habitation, it is known to snatch stray chickens, cats, and dogs on occasion.
Among the largest documented prey items are a half-starved sun bear of that was eaten by a specimen and took some 10 weeks to digest.
At least one case is reported of a foraging python entering a forest hut and taking a child.

Reproduction

The reticulated python is oviparous, adult females lay between 15 and 80 eggs per clutch. At an optimum incubation temperature of, the eggs take an average of 88 days to hatch. Hatchlings are at least in length.

Danger to humans

The reticulated python is among the few snakes that prey on humans. Attacks on humans are not common, but this species has been responsible for several reported human fatalities, in both the wild and captivity. Considering the known maximum prey size, a full-grown reticulated python can open its jaws wide enough to swallow a human, but the width of the shoulders of some adult Homo sapiens can pose a problem for even a snake with sufficient size. Reports of human fatalities and human consumption include:
Increased popularity of the reticulated python in the pet trade is due largely to increased efforts in captive breeding and selectively bred mutations such as the "albino" and "tiger" strains. It can make a good captive, but keepers should have previous experience with large constrictors to ensure safety to both animal and keeper. Although its interactivity and beauty draws much attention, some feel it is unpredictable. It does not attack humans by nature, but will bite and possibly constrict if it feels threatened, or mistakes a hand for food. While not venomous, large pythons can inflict serious injuries, sometimes requiring stitches.