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Varanus acanthurus

Varanus acanthurus (*)

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Reptilia
Subclassis: Diapsida
Infraclassis: Lepidosauromorpha
Superordo: Lepidosauria
Ordo: Squamata
Subordo: Sauria
Infraordo: Platynota
Familia: Varanidae
Genus: Varanus
Subgenus: Varanus (Odatria)
Species: Varanus (Odatria) acanthurus
Subspecies: V. (O.) a. acanthurus - V. (O.) a. brachyurus - V. (O.) a. insulanicus


Varanus (Odatria) acanthurus (Boulenger, 1885)

Type specimen: BMNH 1945.8.30.97

Type location: NW coast of Australia

Vernacular names
Deutsch: Stachelschwanzwaran
English: Ridgetail Monitor, Ridge Tailed Monitor
Français: Varanus acanthurus
日本語: トゲオオオトカゲ
Polski: Waran kolczastoogonowy
Svenska: Taggsvansvaran


* http://www.monitor-lizards.net/species/odatria/acanthurus.html. Accessed on 11 October 2009.
* Varanus acanthurus at the New Reptile Database. Accessed on 11 October 2009.

The Spiny-tailed Monitor or Ridge-tailed Monitor (Varanus acanthurus) is a small species of monitor lizard. They are native to Northwestern Australia and even the western part of Queensland[1] . They live in a variety of habitats from arid to tropical regions. Spiny-tailed Monitors are usually a reddish brown with yellow markings but color and pattern can vary with geographic origin. A distinctive feature is their thick spined tail - hence their common name. The Ridge-tail will scramble into loose rocks or boulders and use its tail to wedge itself in tight. The spikes give the tail good grip on the rocks, making extraction by other predators nearly impossible. In the species' home territory, the tail is often found discarded near Ridge-tail carcasses, indicating that predators of this species consider the tail inedible.[2]

Their diet consists mainly of insects, mammals and lizards including other small monitors.[3]

In captivity

Ridge tailed monitors are one of the more common variants seen in captivity today both in their country of origin and around the world. This is mainly due to their small size, ease of care and availability. As their size and care requirements are very similar to Bearded Dragons, they are considered an appropriate choice for beginning reptile keepers. In captivity this species will thrive if given optimum conditions which are simple to provide if you have the right equipment. A 4x2x2 ft enclosure would comfortably hold an adult pair for the duration of their life however any additional room will be utilized. These monitors burrow in the wild, and need a very deep substrate which they can burrow in without collapse. The substrate should be a dirt/sand mixture which retains water well. It should be between 12 and 16 inches deep. Feeding should be at least daily for the first year, where individuals are offered as much as they will eat over a 14-20 minute period. These monitors will attain a full grown size at around 1.5 to 2 years of age, usually between 45 to 60 cm (18 to 24 inches). They also are believed[by whom?] to have the ability to choose sex depending on the dominance of the group, never a male heavy ratio.


Several subspecies have been recognised:

* Varanus acanthurus acanthurus, Common Ridge-Tailed Monitor, or Red Ackie
* Varanus acanthurus brachyurus, Common Ridge-tailed Monitor, or Yellow Ackie
* Varanus acanthurus insulanicus, Island Ridge-tailed Monitor

References and links

* http://www.jcu.edu.au/school/tbiol/zoology/herp/Varanusacanthurus.PDF
* http://www.kingsnake.com/acanthurus/
* http://www.tailswithscales.com/caresheets/varanids/ackies


1. ^ Pilbarapythons.com
2. ^ Ackie Monitor Caresheets - Tails With Scales - Captive Bred Reptiles
3. ^ Pilbarapythons.com


Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License