Posts Tagged ‘Eastern Brown Snake’

A Brown Snake, Pseudonaja textilis – notes on a post mortem examination

November 27, 2010

She was just trying to cross the road when the ute in front of us ran her over. Writhing in pain  her crushed lungs meant she had no chance of survival. My first thought was a DNA sample so we collected her (just alive ) and continued on our way home. She was DoA. She was 122mm from snout to tail and weighed 404 grams. She had 17 scales around her mid body. Her scales were nice but she had three black ticks and a couple of lumpy scars – presumably from previous ticks. Orange dots peppered her ventral side.  Her anal scale was divided and her post anal sub caudal scales were paired. She was a lovely brown but had subtle stripes around her body which were most noticeable in the mid section. She had a nice svelte line but with a bump of a previous meal. Lizards I expect.

I dissected her from vent to chin exposing her vital organs. There was a significant amount of fat in the anterior abdominal cavity – clearly spring had been good so far. It was in NSW east of Canberra, east of Carwoola  (35°28’56.02″S149°26’40.55″E ) on 20 November 2010.

There were nine eggs in total.  Each was about 26mm in length but there were no signs of development in the egg contents which we a yellowish thick liquid. Lungs were mush from the encounter with the vehicle tyres. Her gut contained a 180mm blue tongue lizard, and a smaller skink complete with its tail. Interestingly there were several shed tails, 3 more than actual skink bodies found. Perhaps she was happy to eat the tail dropped in haste although they do not seem to be substantial enough to be worth much as a food source. Another possibility is that the tails were somewhat harder to digest than the bodies themselves, perhaps even because the venom had not circulated into the tail before being dropped. The venom aids digestion inside the prey animal and starts getting to work breaking down the prey animals body immediately on injection.

I sampled the tip of her tail, her heart and a couple of eggs in 80% ethanol for someone who may wish to compare DNA as an investigation of the geographic distribution of clades in the species. I guess I will send the material, and the ticks, to Rick Shine’s lab at University of Sydney, or the Australian Museum, where there is probably the best chance of connecting the sample with someone who is interested making use of it – now or in the future.

Eastern Brown Snake Pseudonaja textilis