Family : NATRICIDAE
Species : Tropidonophis novaeguineae
Maximum Size : 82 cm

The New Guinea Keelback is one of the smaller species of the genus Tropidonophis, of which 13 species or more occur in PNG.

The specimen shown here was found in the Kutubu area of Southern Highlands Province at an elevation of around 700 metres. The area is dominated by limestone karst scenery and primary rainforest.

In Southeast Asia keelbacks are recognised as being semi-aquatic in their habits, however in karst areas there is little standing water and few permanent streams. It appears that various species of keelback in New Guinea have evolved away from a diet of aquatic frogs and fishes towards a diet of other vertebrates, such as leaf litter frogs and probably forest floor lizards such as skinks and geckos. However, little is reported about the ecology of this species.

The New Guinea Keelback has a head slightly larger than the body, large eyes, and a moderately long tail. The scales are slightly keeled (i.e. possess a raised ridge along the middle of each scale). Its body colour is greyish or brownish, patterned with darker irregular, oblique barring. It lacks a dark stripe behind the eye, which is present in most other Tropidonophis.

The species is known to occur in the Western, Gulf and Central provinces of PNG : the specimen shown here may be one of the first records for Southern Highlands Province. The species is also found in parts of the Indonesian province of Papua (formerly Irian Jaya).

Figs 1 and 2 : A 50 cm specimen from the Kutubu area of Southern Highlands Province, PNG, at en elevation of 700 metres.


References :

O'Shea, M., 1996. A Guide to the Snakes of Papua New Guinea. Independent Publishing Group Pty Ltd.