Madagascar dog head boa

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Madagascar dog head boa
Madagascar dog head boa

Madagascar dog head boa

Systematics
Subordination : Snakes (serpentes)
Superfamily : Boa-like (Booidea)
Family : Boas (Boidae)
Subfamily : Sanziniinae
Genre : Sanzinia
Type : Madagascar dog head boa
Scientific name of the  genus
Sanzinia
JE Gray , 1849
Scientific name of the  species
Sanzinia madagascariensis
( Duméril & Bibron , 1844)

The Madagascar dog-headed boa ( Sanzinia madagascariensis ) is a snake from the boas family native to Madagascar . It is the only species of the monotypic genus Sanzinia .

description

The Madagascar dog-headed boa is about 200 cm long on average. The size of the animals determines the very variable area of ​​distribution. For example, animals are known that have not become larger than 150 cm, while others have become almost twice as large with 250 cm or even a little more. The same is true of the basic coloration of the animals, in the northeast it fluctuates between dark green to blue-turquoise shades, which in the southwest change more to beige-brown. Irregular transverse bands run over the entire body, which are lighter than the basic color, mostly almost white. The pupils are slit vertically and the eyes are black. Most animals have a heart-shaped head shape. The body probably stays a little slimmer due to the very good climbing skills for boas . The tail is also occasionally used as a prehensile tail. As with all giant snakes, the dorsal spurs are located next to the cloaca . Like some species from the subfamily of boa snakes (Boinae), the Madagascar dog-headed boa has heat-sensitive sensory pits, the labial pits . They are arranged in a row of scales along the upper and lower lip and allow this snake to hunt even in complete darkness.

Distribution area

distribution

Madagascar dog head boa

The distribution area of ​​the Madagascar dog-headed boa extends over the entire island of Madagascar , and occurrences of this species have also been recorded on the nearby Mascarene Islands and the island of Réunion . Specimens have also been found on some small offshore islands around Madagascar.

habitat

The very adaptable Madagascar dog-headed boa, with its diverse body and color variants, also populates the most diverse biotopes and microhabitats . They live in barren steppe areas, in cooler mountain regions up to coastal landscapes. By far the largest distribution area, however, extends over the tropical rainforests of the island.

Reproduction

Madagascar dog head boa

Like all boas, the Madagascar dog-headed boa is viviparous ( ovoviviparous ). Females living in the wild mate with several males at the beginning of the mating season. If they meet, they can fight serious rank fights, which usually end with the flight of the inferior animal or - in the terrarium - only with the death of one or, as a result of serious injuries, both animals. The gestation period for females is 6 to 8 months, after which time up to 16 young animals are born. Usually, however, the number of neonates (babies) between 4 and 6 is significantly lower. These are colored red and only change their color to their final color between 6 months and 3 years of age. The young are absolutely tree-dwelling (arboricol).

Color change

As with the green tree python , the color change of the mostly green pregnant females is remarkable . These can become much darker during the gestation period, so that they are almost black on the back. This change in color presumably serves to be able to absorb and store solar energy faster due to the greater energy consumption. After the litter, the animals change back to their normal coloration the next time they molt . As with the tree python, the young of the Madagascar dog-headed boa are colored red. The reddish color gradually disappears after about 1 to 2 years and changes to the basic color of the adult animals.

Systematics

The first scientific description of the monotypic genus Sanzinia was in 1849 by John Edward Gray . It is placed in the family of the Boas (Boidae). After Sanzinia was originally counted to the subfamily of Boa snakes (Boinae), the genus is now assigned to the Sanziniinae. See also systematics of snakes .

Subspecies

Several variants are known in terms of size, drawing, color and shape of the head. This suggests that several subspecies of Sanzinia madagascariensis exist. The 2014 proposed elevation of one of these subspecies to an independent species ( Sanzinia volontany Vences & Glaw, 2004) is controversial.

Protection status

Since the natural habitat of the animals on the island is severely disturbed and is also being destroyed to an ever greater extent, this species, like all snakes native to Madagascar, was heavily protected. It was included in Appendix A of the Washington Convention on the Protection of Species and also enjoys the highest protection status as Appendix A of the European Species Protection Ordinance . This means that Sanzinia madagascariensis may not be kept in Germany without the approval of the competent authority . When the animals are transported, the approval of the responsible state authority must also be available; in addition, there is a separate exhibition and marketing ban for wild specimens. Special provisions apply to the import or export of Sanzinia madagascariensis . A permit from the Federal Agency for Nature Conservation must be available; in addition, the Federal Species Protection Ordinance stipulates that reptile species in Appendix A of the European Species Protection Ordinance must be labeled for the purpose of recognizing the animal.

literature

  • Friedrich-Wilhelm Henkel, Wolfgang Schmidt (ed.): Amphibians and reptiles of Madagascar, the Mascarene, Seychelles and Comoros. Verlag Eugen Ulmer, 1995, ISBN 3-8001-7323-9 .

Web links

Commons : Madagascar dog-headed boa ( Sanzinia madagascariensis )  - Collection of images, videos and audio files