Archive for the ‘biology’ Category

Leech Eats a Water snail

April 10, 2011

This leech was hanging around the pond attached to a new water lily. I put it in the petri dish to have a look under the scope – left a small snail in the dish too. Needless to say the leech emptied the contents of the snail shell over half an hour or so. In 15 minutes its intestines darkened and you could see the food through its translucent body. A few photos are more revealing. It is about 11mm long.

A Copperhead (Austrelaps ramsayi)

March 27, 2011

This one was killed on the road at 35°36’44.58″S 149°33’6.16″E on the Captains Flat to Braidwood road on 26 march 2011. Probably dead for a day or so.

Not sure how widespread they are in the district – NSW DEC Atlas of wildlife seems to be broken today.

Should be a good year for them now and next given that there are a lot of frogs around after the good rain. You can see a distinct vertebral stripe clearly in this one which was about a metre long.

Australeps ramsayi

Austrelaps ramsayi

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

Acetone Yoghurt

November 3, 2010

My favourite breakfast had a bit of spritz about it but it wasn’t out of date. I like my passionfruit yoghurt but did wonder why it seemed a bit lively and tangy this one morning. The following day I was crook with a cold which lingered and so did not have my ‘normal’ breakfast for a week or so. But then, when I cranked out the large tub of favourite yoghurt (still not past it’s use by date) I was overpowered by the acetone smell that emerged. The concentration must have been high as it smelt stronger even than a close up whiff of nail polish remover.

I read a bit online about bacteriological produced acetone. Clostridium acetobutylicum, the most well documented, is sometimes called the “Weizmann Organism”, after Chaim Weizmann, who in 1916 helped discover how C. acetobutylicum culture could be used to produce acetone, butanol, and ethanol from starch using the ‘Acetone Butanol Ethanol process’.

Still this organism seemed a little unlikely in this case as it produces acetone et al in anaerobic conditions, and a tub of yoghurt in the fridge at 4 degrees C didn’t seem like the ideal conditions for acetone production. I froze a sample on the off chance it might be useful later and streaked the yoghurt on nutrient agar in an effort to isolate the relevant organism. Clearly I will have to isolate it from the Lactobacillus and Streptococcus species I expect to find in the yoghurt. I wonder if this is a well known bacteria? I will update if I can identify it.