A quick look at the parts of the uterus in a female stillborn piglet. You may need to click on the speaker icon to hear the voiceover by our lovely assistant Mr Vivi as he points out ovaries, uterine horns, uterus (uterine body)
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.
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.
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!
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
If I had a testis for every time I got a phone call or an email asking if I can supply rats we’d never be out of stock.
Raising and euthanasing whole animals has never been my thing and thinking about all the paperwork involved with licenses and permits and animal ethics approvals just about puts me into a bureaucratic coma.
Consequently the short answer is – “No, we’ don’t supply rats, sorry.” Miss Vivi is, however, very happy to recommend Southern Biological in Victoria and Pisces Enterprises in Brisbane as suppliers of rats for dissection. They both come highly recommended by lab technicians we personally know and love – and trust to know where to go for the good stuff.
Another question I get asked is “Do you know where to get toads?” and invariably my reply is “Do you know any 13 year old boys?”
A little bird tells me, though, that the demand for rats for science in Australia is so great that everyone is having trouble getting enough. So there is a lovely little niche sitting there just waiting to be filled by someone who is willing to have a go at it. Sounds like a job for a labbie to me.
UPDATE MAR 2014: We now supply cane toads ethically euthanased via CO2 asphyxiation in accordance with the latest method endorsed by Biosecurity Queensland. Dissection Connection no longer endorses the use of rats or mice sourced from the pet food industry as no ethical or health standards are applied to the practices of the breeders or suppliers.