Varanus indicus species-complex

Varanus indicus species-complex

Rainer Günther’s Monitor (Varanus rainerguentheri)

Varanus rainerguentheri was described in 2007 (Ziegler, Böhme & Schmitz) from a live animal as well as a museum specimen originally identified as Varanus indicus. With the description of this species and the absence of any reliable specimens of indicus from Halmahera, the presence of Varanus indicus s. str. on this island needs to be reconfirmed.

Rainer Günther’s monitor inhabits saltwater environments including coastal areas, mangroves, and Nypa palm swamps (Weijola 2010).

Distinctive Features (from Ziegler, Böhme & Schmitz 2007)

Background color: Greyish-black

Dorsal pattern: Blackish ocelli with yellow centers, arranged in transverse rows

Tail pattern: Transverse rows of ocelli as on the dorsum; banded towards the tip

Throat/ventral pattern: Ventral surface cream to greyish; throat unpatterned; ventral surface possessing faint bands (Note: Due to questions regarding the origin of the holotype, there is still debate as to exactly what constitutes Varanus rainerguentheri; see Weijola 2010. The description given here is that of the holotype as given in the species’ description)

Post-ocular stripe: Present, though this feature varies widely among individuals (Weijola 2010)

Tongue color: Pink with a dark grey tip

Range

Currently known to occur throughout Halmahera as well as on Morotai, Ternate, Tidore, Gebe, Bacan, Kasiruta, and Obi (Weijola 2010). Its range has recently been expanded to include Buru (Somma & Koch 2012) and is likely even more widespread in the Moluccas.

Originally recognized as an unknown indicus-type animal, an examination of similar museum specimens (Somma & Koch 2012) has identified these specimens as likely juvenile rainerguentheri. No information available concerning specific locality. Photos courtesy of Firdaus Karim.

Note barred throat which necessarily distinguishes it from Varanus indicus sensu stricto. This specimen is also pictured in Somma & Koch 2012.

 

Note a strong resemblance to the photograph of a suspected juvenile Varanus rainerguentheri which appears in Ziegler et al 2007.

Status in Captivity

Specimens corresponding to the description of Varanus rainerguentheri have been imported though usually described as generic 'indicus'. This confusion is due to this species' close resemblance to many other indicus-complex monitors and the fact that determining the taxonomy of these animals to a certainty is rarely a high priority among importers and dealers. Nor is this the first time in which "Varanus indicus" have been sold only to prove to be some other described taxon (see Varanus juxtindicus).

Sources

Somma, M. & A. Koch (2012): New morphological and distributional data of Varanus rainerguentheri Ziegler, Böhme & Schmitz, 2007 (Squamata: Varanidae), an endemic and little-known monitor lizard species of the Moluccas, Indonesia. Salamandra 48: 207-212.

Weijola, V. S. A. (2010): Geographical distribution and habitat use of monitor lizards of the north Moluccas. Biawak 4 (1): 7-23. (http://www.varanidae.org/Vol4_No1.pdf)

Ziegler, T., Böhme, W. & A. Schmitz (2007): A new species of the Varanus indicus group (Squamata, Varanidae) from Halmahera Island, Moluccas: morphological and molecular evidence. Mitt. Mus. Nat.kd Berlin, Zool. Reihe 83 (2007) Supplement, 109-119.