Spiny-tailed monitor
Spiny ( Varanus acanthurus )
The Spiny ( Varanus acanthurus ) is an Australian Schuppenkriechtier from the family of monitor lizards ( Varanidae ). In Australia it is called Ridge -tailed Monitor or Spiny -tailed monitor.
Features
The Spiny reaches a maximum total length of 70 cm, the tail length corresponds to 1.3-2.3 times the head-body length. On the body top, the species is usually drawn dark brown with light spots, which often include some darker scales, and thus form ocelli. The tail has a very prickly squamation and is round in cross section. To the midsection 70-115 rows are arranged by smooth scales. Of the similar species baritji V. and V. primordius the Spiny can be distinguished because it has bright vertical stripes on the neck.
Distribution and habitat
The Spiny- populated in Australia, the northern half of Western Australia and the Northern Territory and the eastern to north-eastern parts of Queensland. This species inhabits dry areas, especially with rock formations.
Subspecies and systematics
The Spiny is part of a purely Australian Radiation of rather small lizards, which is defined as a subgenus Odatria. There it is attributed to V. acanthurus group.
For a long time you split the Spiny in the 3 subspecies: Suspected acanthurus, suspected brachyurus and V. insulanicus which inhabits only the Groote Eylandt and the islands of the Wessel Group. However, mtDNA analysis was known that V. a brachyurus and Suspected acanthurus no natural group ( monophyla ) form. Suspected insulanicus contrast is therefore the type V. baritji closer than the continental spread Stachelschwanzwaranen. So This subspecies is probably a distinct species dar. Wilson & Swan (2010) identify suspected insulanicus even as a subspecies of V. acanthurus, which is distinguished by its darker color and more bands like pattern of the nominate - Stachelschwanzwaranen.
Way of life
The Spiny like all monitor lizards a diurnal loner, and predominantly ground -dwelling. He hides at night and often on the day in crevices or under rocks, more rarely, he also uses spinifex grasses as shelter. The Spiny characterized by lower activity and metabolic rates than other dragons, and is probably an ambush predator. The main prey of wild Stachelschwanzwarane are insects such as grasshoppers, beetles and cockroaches, and small lizards such as geckos, skinks and small Agamas. Rare captured the dragons other insects, spiders, snails or young marsupials. Its water requirement covers the Spiny probably about 70% of its food.
Stachelschwanzwarane be infested by ticks of the genus Amblyomma and Aponomma and parasitized by nematodes of the genus abbreviata. While just under 3/4 is attacked by free-living Stachelschwanzwaranen with roundworms, the tick infestation is relatively low. Among the predators of the lizard include snakes.
Reproduction
In captivity, the scrim of Stachelschwanzwarans contain up to 18 eggs, which hatch juveniles of 15 cm length after 3-5 months. About the reproduction in the wild are only sparse data. Sexual maturity is apparently reached by males from 12 cm head-body length and females from 10-14 cm snout-vent length. Ovulation of females is in August and November (early dry season), and it is apparently determined annually a nest in a hole in the ground.