Despite being a bit like Penny from The Big Bang Theory when it comes to craft I do like to have a go from time to time. As long as it is easy, doesn’t involve waiting around too much for glue or paint to dry or a special trip to the shops I’m usually up for it.
Enter the DIY Papercraft Skull with Articulated Jaw from Skull-A-Day. TaDa!
papercraft skull made with free printable from skull-a-day
Assemble and run around the house snapping the jaws and making Unh Unh Unh noises
I reckon this has got end of year classroom activity written all over it. Add a bit of glitter, felt and cotton wool and you’d have yourself a Snapping Santa Skull.
So, I thought it would be a good idea to prep a duck head and feet set to display the bones. Sounds like a good idea, right? You can make comparative anatomy displays for the classroom. Fabulous!
I started with this:
Duck Head and Feet Set
Threw the lot into a pot and simmered it for about two days. It didn’t smell as bad as I thought it would. Kind of like soup.
5 things I learned about preparing bones for display:
Take as much of the skin, muscle and viscera off the bones as you can BEFORE you start. Now I have spent at least an hour picking bits of meat and skin off tiny bones and checking meticulously that I haven’t missed anything.
Put the separate pieces into SOMETHING before you start. Bags made of old pantyhose would have done the trick. Now I have no idea which bones belong to the left foot and which to the right foot.
Cleaning bones and laying them out on a tray made me feel just like Temperance “BONES” Brennan – even though I had no idea what I was looking at most of the time.
It was a VERY good idea not to throw the chicken head and feet into the pot at the same time!
As this kid laments, there is next to no info on the web about articulating bird skeletons. I will definitely post a picture of the finished product with some more tips and tricks for you because you are going to be hard pressed to find it elsewhere. Stay tuned, Vivsters.
To help satisfy the demand for whole animal specimens we’ve decided to stock cane toads. Mr Vivi has been collecting and packaging toads all summer and we now have a freezer full of the hoppers. They are packaged individually and identified by sex. So, consult the current price list and choose whether you want boys or girls. Available until they run out and collection starts again in spring.
Cane toads. Female on the left, male on the right. Notice the distinctive markings which can be partially used to sex a toad.
Dissection
A cane toad dissection allows the biology teacher to cover many aspects of body systems including, skeleton, musculature, heart and arterial, venous, digestive and respiratory, urogenital and nervous systems in a series of practicals using the same specimen. Dissection Connection stocks cane toads with a snout vent length (SVL) of over 80mm that have been sexed and packaged as individual male and female specimens. In stock soon, ‘The Zoology Coloring Book’ by Lawrence M. Elson to compliment your class.
Many methods have been suggested. Step-wise cooling and freezing was for some time the recommended method but recent work has found this method can cause distress and pain to the animal evidenced by behavioural responses to this and other methods. One of the mechanisms that cause pain in this method includes freezing in the blood, producing ice crystals that are transported around the vascular system and cause pain.
A joint project between The Australian Government, The New South Wales Government and The University of Wollongong (CAN001 Methods for the field euthanasia of cane toads, T. Sharp, A. Lothian, A. Munn and G. Saunders: 2011) found the preferred methods were:
stunning followed by decapitation
gassing with carbon dioxide (CO2) for >4 hours
Due to the numbers handled and the requirement for an intact specimen for dissection, Dissection Connection has opted for method 2, gassing with CO2.
This CO2 euthanasia SOP is that recommended on the Queensland DETE animal ethics website and by Biosecurity QLD. We follow the procedures in the original scientific paper which outlines a number of extra steps that DETE don’t mention.
Specimen preparation
After successful euthanasia, toads are measured. Only those with minimum snout-vent-length (SVL) of 80mm are kept. Toads are sexed as per Narayan, Christi, Morely and Trevenen (2008) based on external morphological features and presence/absence of vocal sac openings in the mouth.
Toads are then set in trays, frozen overnight and vacuum packed.
Workplace health and safety
Use nitrile or chemical gloves to handle, NOT vinyl gloves for handling toads. I used vinyl gloves for about half an hour handling dead toads, my fingers were tingling for about an hour afterwards.
Nitrile gloves should be used when handling dead toads and conducting dissections as toxins may be present on the skin of the toad.
Have fun with this, it’s a great dissection!
References
Narayan, E., Christi, K., Morely, C., and Trevenen, P. (2008). Sexual dimorphism in the cane toad Bufo marinus: a quantitative comparison of visual inspection methods for sexing individuals. Herpetological Journal 18: 63-65.
Sharp, T., Lothian, A., Munn, A. and Saunders, G. (2011). CAN001 Methods for the field euthanasia of cane toads
