Keelback (Tropidonophis mairii)
Other common names: Freshwater Snake
Toxicity: Non-venomous.
Description: The Keelback is named for the distinctive ridges running lengthwise along the top and sides of the body. The head is distinct from the solid body. Colouring is uniform along the body ranging from grey through olive to brown. The brown colouring appears most common in the Tweed. The mouth is slightly upturned in a ‘smile’ and the scales on the upper lip have dark sutures between them. The scales are rough with a dull appearance. The underside is an off white, tinged with orange or pink along the edges. Keelbacks can grow to 90cm but are more common in the 50-75cm range.
The Keelback is similar in appearance to the Rough-scaled Snake which is highly venomous.
The Keelback is a member of the Colubrid family with the Green and Brown Tree Snakes.
General habits: The Keelback is distributed widely along the eastern and northern coast of Australia from around Grafton north. As it’s diet is heavily slanted to frogs, it’s favourite locales are around water sources. It is active during the day and night depending on temperature. It is a ground dweller but can climb. The Keelback is harmless but tends to dart around aggressively if cornered or threatened and can release a foul odour if handled. It is possible for this snake to shed it’s tail, but unlike a lizard, it will not regrow.
Diet: Mainly frogs and tadpoles including small Cane Toads.
Locally: Found in all locations in the Tweed. Despite the abundance of water and Cane Toads, this snake is relatively uncommon around houses.
Reproduction: Keelbacks lay 5-12 eggs.
The raised lines or keels running lengthwise along the snake give rise to it’s name.
Great shot of the head showing the loreal scale (unique to non-venomous snakes) the upturned mouth that looks like it’s smiling, and the dark lines between the scales on the upper lip. The Rough-scaled Snake doesn’t have a loreal scale, the mouth is flatter and there are no dark lines between the scales on the upper lip.