Sepik monitor lizard

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Sepik monitor lizard
Sepik monitor lizard at Leipzig Zoo

Sepik monitor lizard at Leipzig Zoo

Systematics
without rank: Toxicofera
without rank: Sneaky (Anguimorpha)
Family : Varanidae
Genre : Monitor lizards ( varanus )
Subgenus : Euprepiosaurus
Type : Sepik monitor lizard
Scientific name
Varanus jobiensis
Ahl , 1932

The Sepik monitor lizard ( Varanus jobiensis ) is a little researched lizard from New Guinea . It lives in the island's lowland rainforest and feeds primarily on insects.

features

The Sepik monitor lizard is a medium-sized, rather slender monitor lizard, with a conspicuously angular head, large eyes and a long neck. The laterally flattened, non-graspable tail identifies the Sepik monitor lizard within the subgenus Euprepiosaurus as a member of the Varanus indicus group. The species reaches a maximum length of about 1.2 m, the tail is 1.48-1.83 times as long as the head and trunk together.

The upper side of the body is dark olive to black, with numerous small, light spots. These are more or less clearly arranged as transverse bands. The tail is banded blue-turquoise. The top of the head is slate gray, often tinged slightly blue; it lacks any drawing. The tongue is pink. The underside of the body is whitish, except for the conspicuously pink, reddish or orange throat. The legs are dark olive and mottled blue to green. These speckles appear more intensely on the hind legs. The drawing of the young animals is more intense than that of the old animals, and the dot-bands on the back are further apart.

Compared to related species, the Sepik monitor lizard has very small scales. He has 164–201 rows of scales around the middle of the body, between the back of the head and hind legs there are 163–196 rows of scales.

distribution and habitat

The Sepik monitor lizard inhabits New Guinea and the offshore islands of Yapen , Biak , Salawati and Weigeo . The evidence of this species so far suggests that the Sepik monitor lizard is widespread in large parts of the New Guinea lowlands; it was found up to 900  m above sea level. It inhabits rainforests and alluvial forests and prefers areas with dense vegetation; Mangrove forests are avoided.

Way of life

Like all monitors, the Sepik monitor is a diurnal loner. It is mostly active on the ground and takes refuge in trees if it is disturbed. Often the way it is observed how it claws at tree trunks, inflates its conspicuously colored throat and lifts its head. In the rather monochromatic lowland rainforest, this could be a means of intra- or inter-species communication. Due to the uniform climate, the species is active all year round.

In Western New Guinea , Sepik dragons have often been seen running off nearly dry creek banks, hunting for small fish or crabs that are easy to catch. When examining the stomach contents of six preserved museum specimens, however, insects such as cockroaches , grasshoppers, beaked beetles, bees and butterflies made up almost three quarters of the prey objects. Tarantulas, frogs and reptile eggs were also identified as stomach contents. Captive Sepik monitor lizards take on insects, chicks, mice, frogs, small lizards and fish.

Nothing is known about reproduction in nature. The offspring succeeded several times in captivity.

Systematics

It was first described in 1932 by the German zoologist Ernst Ahl (1898–1943). Ahl described the species as Varanus indicus jobiensis , a subspecies of the Pacific monitor . In his classic monograph on the monitor lizards from 1942, German herpetologist Robert Mertens (1894–1975) declared the subspecies jobiensis to be invalid and the nominate form V. i. indicus same. In 1991 the German zoologist Wolfgang Böhme again proved that the Sepik monitor lizard is an independent species. The name V. karlschmidti is a synonym of V. jobiensis ; this species was described by Mertens in 1951 on the basis of a specimen copy, which is actually a V. jobiensis . The older name jobiensis has priority. According to analyzes of mitochondrial DNA and the hemipenis morphology , Varanus jobiensis is assigned to the subgenus Euprepiosaurus within Varanus ; there he belongs to the Varanus indicus group.

Danger

The locals hunt and eat the species with snare traps, and professional hunters occasionally capture live specimens for the international pet trade. The CITES authorities approved the export of 5,538 live specimens for this purpose between 1975 and 2005. The number of unreported cases could be higher. In the future, clearing the rainforest could also endanger the species. However, the species is currently not classified as endangered, as the pressure from hunting is limited, and protective measures still seem unnecessary.

swell

  • KM Philipp, T. Ziegler & W. Böhme (2004): Varanus jobiensis . In: ER Pianka & DR King (Eds.): Varanoid Lizards of the World , pp. 189–192. Indiana University Press, Bloomington & Indianapolis, ISBN 0253343666
  1. ↑ a b c d Varanus jobiensis in the endangered Red List species the IUCN 2010. Posted by: Bennett, D. & Sweet, SS, 2009. Accessed February 3, 2011th
  2. ↑ KM Philipp, T. Ziegler & W. Böhme (2007): Preliminary Investigations of the Natural Diet of Six Monitor Lizard Species of the Varanus (Euprepiosaurus) indicus Group . Mertensiella 16 ( Advances in Monitor Research III ), pp. 336-346
  3. ↑ T. Ziegler, A. Schmitz, A. Koch & W. Böhme (2007): A review of the subgenus Euprepiosaurus of Varanus (Squamata: Varanidae): Morphological and molecular phylogeny, distribution and zoogeography, with an identification key for the members of the V. indicus and the V. prasinus species groups . Zootaxa 1472, pp. 1-28
  4. ↑ AP Pernetta (2009): Monitoring the Trade: Using the CITES Database to Examine the Global Trade in Live Monitor Lizards (Varanus spp.) . Biawak 3 (2), pp. 37–45 ( full text ; PDF file; 1.94 MB)

Web links

Commons : Varanus jobiensis  - collection of images, videos and audio files