Cane Toads - Frozen Biology Specimen

Introduction

Cane toads, Rhinella marina, were introduced into Queensland in 1935 to control scarab beetles, which were pests to sugar cane. The cane toad is tough, adaptable, as well as being poisonous throughout its life cycle and has few predators in Australia. This is bad news for competing native amphibians, and it may be responsible for the population decline of the few snakes and other species that do prey on it.

Cane toads have been very successful as an invasive species, expanding their range through Queensland, northern New South Wales, the Northern Territory, and the north of Western Australia.

Dissection & Processing

Cane toad dissection allows teacher to cover many aspects of body systems in amphibians including skeleton, musculature, heart and arterial, venous, digestive and respiratory, urogenital and nervous systems in a series of practicals using the same specimen.
Male and Female toads are available, These specimens are suitable for dissections, wet specimens mould & Casting and skin mount taxidermy

Euthanasia

Toads are collected and placed in a fridge for 24 hours before being placed in the freezer for euthanasia. this process is consider humane. This research monitored body temperatures and the brain activity of cane toads throughout cooling and freezing which shows that they slip into a coma-like state (called torpor) during the cooling period which inhibits brain activity and prevents their brain from recognising the pain experienced from ice crystals forming in their veins which occurs during freezing.
This confirms that cooling and then freezing is a humane method of euthanasia

Delivery & Collection

Specimens are packed individually in a heat sealed leak proof bag, all specimens are shipped frozen

Western Australian residences can arrange to collect purchased specimens from West Perth 6005
Frozen specimens are shipped by Australia post.
To ensure the specimens stay in good condition please make arrangements to refrigerate or refreeze immediately after arrival. Overnight freight or express post can be arranged with additional changes applied

Specimen preparation

After euthanasia, toads are measured. Those with minimum snout-vent-length (SVL) of 80mm are kept.
Toads are sexed frozen overnight and vacuum packed individually.

Cane toads paratoid glands can be removed and saved frozen, the glands can then be used to create lures for tadpole trapping.
Cane toads paratoid glands can be sent frozen to Watergum community for Environment.

Workplace health and safety

Using the correct personal protective equipment when handling biological materials is essential when conducting necropsies. Risk assessments of the classroom/labs and specimens should be conducted when processing biology materials

Nitrile gloves and safety glasses to be warn when handling cane toads and conducting dissections as toxins may be present on the skin of the toad.
Aprons can be useful to reduce any contamination exposed to cloths.

Disposal of cane toads

As with all dissection material, toads that have been dissected should be securely wrapped in several sheets of newspaper and double bagged before disposal in general refuse for deep burial in landfill sites.
Secure wrapping and double bagging will generally deter animals from eating dissected toads in garbage bins, in preference for more easily attained food sources.

Useful reference:

https://journals.biologists.com/bio/article/4/7/760/1463/Is-cooling-then-freezing-a-
humane-way-to-kill

https://watergum.org/humane-euthanasia-and-disposal-of-cane-toad-adults/

file:///C:/Users/teori.shannon/Downloads/ASSIST%20-%20Dissecting%20cane%20toads%20in%20WA%20-%202019-02-22%20(2).pdf