Sessional Committee on Environment and Sustainable Development Written Submissions Received Volume 2 Issues associated with the progressive entry into the Northern Territory of Cane Toads October 2003
Tabled Paper 1123
Tabled Papers for 9th Assembly 2001 - 2005; Tabled papers for 9th Assembly 2001 - 2005; Tabled papers; ParliamentNT
Tabled by Delia Lawrie
Made available by the Legislative Assembly of the Northern Territory under Standing Order 240. Where copyright subsists with a third party it remains with the original owner and permission may be required to reuse the material.
Dr Mahony Written Submissions Cane Toad Inquiry Report Volume 2 170 as is known, is restricted to one single mating with a single partner per season, and adults are relatively sedentary around established breeding sites. It is postulated that an effective way to control a highly fecund species, such as the Cane Toad, would be to reduce their reproductive potential. The aim of this project is to investigate genetic methods to produce sterile male Cane Toads that have libidos equal or greater than normal males. This project does not aim to study whether the population dynamics of the toad are amenable to this approach. We have taken the position that it is first necessary to determine whether sterile males can be produced, before this question should be considered. Apart from offering the possibility of a multi-pronged attack to control the toad, the proposal has the following advantages. It does not involve introducing viral pathogens or the testing of specificities of any pathogens (i.e. it does not involve introducing a disease to kill toads or the need to test a large array of native animals to ascertain whether the disease is harmless to them). It does not require a vector (i.e., there is not need to have a means to spread an introduced disease). It does not involve genetically engineered pathogens. The method of producing triploids does not require any harmful reagents. Objectives To produce sterile male toads that have a normal libido and seek to mate females. We aim to determine whether this can be achieved by producing triploid males that grow normally and have normal testes with respect to the production of male hormones, but which produce abnormal sperm. When these males mate with a female their sperm are either not capable of fertilising eggs or development will not proceed. Triploidy is known to result in sterility in numerous animal groups. To achieve this outcome a number of steps must be shown to be possible in the Cane Toad. Firstly, experiments need to be conducted to show that triploid animals can be produced. We have already successfully produced triploid cane toads using the simple method of cooling cane toad eggs immediately after fertilisation. The technology that would need to be geared up is already applied in some sections of the aquaculture industry. Methods successful used on fish and frogs include cold, heat and pressure shock, and the use of some specific biochemicals. Secondly, we would need to demonstrate normal growth and development of triploid toads. We have grown triploid cane toads through the larval stage to beyond metamorphosis and there is no major impediment to the concept at this stage of the life cycle. We have not grown young toads through to adulthood to confirm that this is possible. Thirdly, if triploids toads grow to adulthood we would need to assess whether they have normal libido (hormone profiles and microscopic examination of testes) and demonstrate that any sperm produced are abnormal.
Aboriginal and Torres Strait Islander people are advised that this website may contain the names, voices and images of people who have died, as well as other culturally sensitive content. Please be aware that some collection items may use outdated phrases or words which reflect the attitude of the creator at the time, and are now considered offensive.
We use temporary cookies on this site to provide functionality.
You are welcome to provide further information or feedback about this item by emailing TerritoryStories@nt.gov.au