Boelen python
| Boelen python | ||||||||||||
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Boelen python ( Simalia boeleni ) |
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| Simalia boeleni | ||||||||||||
| ( Brongersma , 1953) |
The Boelen-Python ( Simalia boeleni , Syn. : Morelia boeleni ), also Boelens python , belongs to the family of pythons (Pythonidae), where it is in the genus Simalia asked. It is endemic to New Guinea and inhabits the highland rainforests here. Practically nothing is known about the biology of this snake.
description
Build, length and teeth
The Boelen python is a relatively sturdy python with a cylindrical body cross-section and a broad head that is clearly separated from the neck. Its rather long, strong prehensile tail can make up at least 13% of the entire body length. Due to the small amount of data, there is still no well-founded information on the average and maximum length of the species. In captivity, at least males with a total length of 2.75 meters and females with a total length of 2.8 meters have been successfully brought to reproduction. In addition, several animals with a total length of over 3.3 meters are known from captivity. An individual captured in Papua New Guinea in the 1980s and exported to the United States is said to have had a total length of 4.27 meters (168 ″).
The bit consists of thin, elongated teeth that are continuously pointed and curved towards the throat and become increasingly smaller from the tip of the mouth to the throat. At the front of the upper oral cavity is the intermaxillary bone with two small teeth. The upper jaw bones each have 17 to 18 teeth. Towards the middle of the upper oral cavity, the palatine bone lies parallel to the maxillary bones in front and the wing bone further back . The former has 5 and the latter 10 to 14 teeth. The lower jaws each have 17 to 19 teeth.
Like other original snakes of the python and Boaartigen has the Boelen-Python visible pelvic spur .
Scaling
The rostral (snout shield) visible from above has, like most other pythons, two deep labial pits . The nostrils are each positioned in the upper rear part of the large nasal (nasal shield). A clearly recognizable seam runs from the nostril to the rear edge of the shield. Towards the middle of the head, the nasals are separated by a pair of almost square internasals ( internose shields ). From the tip of the snout along the midline of the top of the head, the internalsals are followed by a large, long front pair of prefrontalia (forehead shields). The rear smaller pair of prefrontalia lies laterally against the anterior prefrontalia and is completely separated by it. In some cases, not only the posterior prefrontalia, but also the posterior tips of the anterior prefrontalia border directly on the large, simple, oval to hexagonal frontal (frontal shield) behind it . Behind the frontal two large pairs of parietals ( parietal shields ) adjoin , of which the rear pair is longer. Over the eyes is ever a great Supraoculare (via eye shield). Preocularia (forehead shields) exist two, of which the upper one is enlarged. Postocularia (posterior eye shields) exist two to four. Subocularia (under-eye shields) are absent in this species. On the side of the head between the eye and nostril there are 6 to 12 small Lorealia (rein shields), of which the top two are significantly enlarged. Of the 8 to 12 supralabials (shields of the upper lip), the foremost three bear diagonal, deep labial pits. Of these, supralabials number 6 and usually number 5 also touch the lower edge of the eye; the seventh or eighth supralabial is often doubled in size as the rest. Infralabialia (lower lip shields ) there are 14 to 17, of which 5 to 7, starting at infralabial number 7 or 8 and running to number 11, 12 or 13, have deep labial pits. In addition, the chin skin forms a longitudinal fold in the area of the lower labial pits, which partially covers them. The chin pit is provided with three to six pairs of shields.
The number of ventralia (abdominal shields) varies between 282 and 298, the number of dorsal rows of scales in the middle of the body between 44 and 51. From the cloaca to the tip of the tail there are 57 to over 64 mostly paired subcaudalia (underside shields of the tail). The anal (anal shield) is undivided.
coloring
The entire top of the body is held in a shimmering blue-violet black lacquer. The abdomen and the lower half of the flank are colored in the front two thirds of the body in a contrasting white, lemon yellow, yellow to yellow-green. From here, light, one to two shields wide, diagonally head and back diagonal ribbons rise up into the black back area at regular intervals. Some of these bands are broken or even fragmented into several bright spots. In the front quarter of the top of the body, the ligaments on either side can be in contact with each other through an optional series of bright spots along the spine. The flank ligaments get lower and lower towards the middle of the body, but increasingly wider at their base. At the same time, the black color of the back begins to infiltrate more and more towards the abdomen and reaches the abdomen after two thirds of the length of the body, which completely suppresses the flank ligaments and the abdomen becomes increasingly black until only a few light spots remain at the end. The tail is completely black all around.
The top of the head is uniformly black. There is usually a relatively large bright spot in front of the eye and another bright spot is often at the back of the nostril. The lateral outlets of the two labial pits of the tip of the snout are each white to yellow, the rear shields of the upper lip are black on their front and white to yellow on their back. The lower lip shields, which are also white to yellow, are often provided with a black stripe on their front, which does not always necessarily reach the edge of the mouth. In addition, a black stripe often arises at the corner of the mouth and runs along the length of the lower labial pits along the lower edge of the lower lip shields towards the tip of the head. The throat is white to yellow and in certain individuals it is provided with black spots, which occasionally spread to the foremost part of the underside of the neck. The tongue is light brown with whitish margins. The iris is a dark silver black.
Color change
Boelen pythons undergo a striking ontogenetic color change. Hatchlings have a reddish-brown back coloration, which is interrupted at regular intervals by narrow, light-brown transverse ligaments that often fuse across the back. The color of the ventral side is mostly yellow and spreads to the flanks. The lip shields are alternately striped dark brown and yellow. The eyes of the young are golden. As it grows, the reddish brown color on the back becomes increasingly darker and the light bands become more and more prominent. Adolescent animals already show the typical black color, but still have a few small, red-brown spots scattered around them.
distribution and habitat
The Boelen python is endemic to New Guinea. According to current knowledge, its distribution area is limited to the relatively cool, low-light highland rainforests from around 1000 meters above sea level to the tree line. In western New Guinea it has occasionally been detected at altitudes well over 1750 meters above sea level and in Papua New Guinea even at over 2000 meters. The sparse localities to date indicate a distribution along the entire mighty central mountain range, which divides New Guinea into an eastern and a western part, as well as two allopatric populations separated by lowland forests on the Huon Peninsula and the Goodenough Island . Initial studies suggest that the animals along the central mountain range are at least two populations that are partially or completely separated by the high mountains.
Way of life
The behavior of the species is still almost unexplored. This agile python has been spotted in its natural habitat both on the ground and excellent climbing in trees. At least in captivity, adult animals are ostensibly arboricolous . According to Worrell (1958), water birds belong to the range of prey of the Boelen python. The Papua eagle (Harpyopsis novaeguineae) is one of its natural enemies .
There is also no information available on reproduction in the field. In a couple kept in captivity, mating could be observed over and over again for six months. The freshly moulted female usually seemed to be the stimulus for mating. Often the male would then approach from a side that was beyond the view of the female and nudge her all over the body with his snout. If this did not move the female, he began to vigorously scratch her torso with his anal spurs at a rhythm of once or twice a second. As soon as the female began to crawl away, he immediately pressed his head to hers and snuggled his entire length against her. The pairings that followed lasted up to 50 minutes, whereby the anal spurs were no longer used, the tails were barely wrapped around and both partners remained virtually motionless. The copulations took place both on the ground and in the branches. Comment fights between males were not observed, a slightly smaller male kept in the same enclosure avoided his competitor in every confrontation. In the few cases where Boelen pythons have so far been successfully reared in captivity, the female laid between 14 and 20 eggs, which were approximately 83 × 45 millimeters in size and weighed about 107 grams. After hatching, the young were between 40 and 46 centimeters long.
Systematics
Brongersma described the way in 1953 on the basis of two individuals, which at that time in Netherlands New Guinea stationed surgeon Dr. KWJ Boelen sent to the Reich Museum for Natural History in Leiden . In his honor, this python was given its scientific name Liasis boeleni , or today Simalia boeleni . Unaware of this description, Worrel described another individual of this python as liasis toronga in 1958 . In 1969, Brogersma added three other animals to his description and synonymized Liasis toronga with Liasis boeleni .
The Boelen python is most closely related to the five species of amethyst pythons . The characteristic commonality of Boelen and Amethyst pythons is the presence of at least two pairs of large apex shields.
An internal molecular genetic investigation based on 89 individuals from at least partially different distribution areas suggests that there is a strong genetic impoverishment among the Boelen pythons. The reason for this drastic selection is seen in several rapidly successive and only recently occurred strong climatic fluctuations on the highlands of New Guinea.
Danger
Although the population size and density of the Boelen python cannot yet be precisely estimated, it seems to be not threatened by living in areas that have so far hardly been touched by humans. Due to continuous population growth and increasing exploitation of its habitat for mining, oil production and wood export, it will come under increasing pressure to exist in the future. In Papua New Guinea, the Boelen python is the only reptile under special protection. Like the national animals , the birds of paradise , it may not be caught or killed by non-locals, which largely prevents the export of hides or live animals. In Western New Guinea there are no country-specific protective measures, but the Washington Convention on the Protection of Species applies , which means that the Boelen python listed in Appendix II is subject to trade and export restrictions.
In addition, several zoos in the USA and Europe have started breeding programs to preserve the species and relieve the live animal trade. So far, however, completely unsuccessful.
swell
Individual evidence
- ↑ a b c d M. O'Shea: A guide to the snakes of Papua New Guinea . Craft Print Pte Ltd., Singapore 1996, ISBN 9980-916-96-6 , pp. 78-79.
- ↑ a b c d e f g L. D. Brongersma: Notes on the New Guinean reptiles and amphibians. II. Proceedings Koninklijke Nederlandsche Akademie van Wetenschappen, Amsterdam 56, No. 3, 1953, pp. 317-325.
- ^ A b c d E. Worrell: A new Papuan python . Proceedings of the Royal Zoological Society of New South Wales 1956-1957, 1958, pp. 26-27.
- ^ A b c d e S. B. McDowell: A catalog of the snakes of New Guinea an the Solomons, with special reference to those in the Bernice P. Bishop Museum. Part II. Anilioidea and Pythoninae . Journal of Herpetology 9, 1975, pp. 1-79.
- ↑ a b c d e J. B. Murphy, WE Lamoreaux, DG Barker: Miscellaneous Notes on the Reproductive Biology of Reptiles. 4. Eight Species of the Family Boidae, Genera Acrantophis, Aspidites, Candoia, Liasis and Python . Transactions of the Kansas Academy of Science 84, No. 1, 1981, pp. 39-49.
- ↑ AR Flagle, ED Stoops: Black Python - Morelia boeleni . Edition Chimaira 2009, ISBN 978-3-930612-86-4 , p. 69.
- ^ AG Kluge: Aspidites and the Phylogeny of Pythonine Snakes . Records of the Australian Museum, Supplement 19, 1993, ISBN 0-7310-1164-3 , p. 65.
- ↑ a b c d e f g h J. G. Walls: The Living Pythons - A complete guide to the Pythons of the World . TFH Publications, 1998, ISBN 0-7938-0467-1 , pp. 113-117.
- ↑ a b L. D. Brongersma: Notes on Liasis boeleni Brongersma . Proceedings Koninklijke Nederlandsche Akademie van Wetenschappen, Amsterdam 72, No. 2, 1969, pp. 124-128.
- ↑ a b c d e C. C. Austin, M. Spataro, S. Peterson, J. Jordan, JD McVay: Conservation genetics of Boelen's python (Morelia boeleni) from New Guinea: reduced genetic diversity and divergence of captive and wild animals . Conservation Genetics 11, 2010, pp. 889-896.
- ^ R. Graham Reynolds, Matthew L. Niemiller, Liam J. Revell: Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling. Molecular Phylogenetics and Evolution, Volume 71, February 2014, Pages 201-213, doi: 10.1016 / j.ympev.2013.11.011
- ↑ MB Harvey, DG Barker, LK Ammerman, PT Chippindale: Systematics of Pythons of the Morelia amethistina Complex (Serpentes: Boidae) with the Description of three new Species . Herpetological Monographs 14, 2000, pp. 139-185.
