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About the draft report

This is a report of the potential impacts on the environment* of amending the 'List of Specimens Suitable for Live Import' for the purposes of the Environment Protection and Biodiversity Conservation Act 1999, to include the Tomato Frog (Dyscophus antongilii).

Contents

• 1. Provide a summary of the proposed activity
• 2. Provide information on the taxonomy of the species
• 3. Describe the current status of the species in its natural range
• 4. Describe the current status of the species in Australia
• 5. Assess the likelihood that the species could establish in the Australian environment, and Pest History
• 6. Assess the consequences of the species becoming established in the Australian environment
• 7. Provide information and results of any other similar assessments undertaken on the species
• 8. Provide information on all other relevant Commonwealth, State and Territory legislative controls on the species and the assessment upon which these controls were based
• 9. Assess what conditions or restrictions, if any, could be applied to the import of the species to reduce any potential for negative environmental impacts
• 10. Provide an overall assessment on the potential impacts of importing the species, include both the potential impacts of the particular import that is proposed and the potential impacts of the species per se
• References
• Please Comment

1. Provide a summary of the proposed activity

Live Tomato Frogs, Dyscophus antongilii, will be imported into Melbourne Zoo on behalf of the ARAZPA Reptile & Amphibian Taxon Advisory Group (TAG).

The TAG is proposing to import a total of six species within the genera Dendrobates, Pyxicephalus, Ceratophrys, Megophrys and Dyscophus for the purpose of exhibition and support the conservation of threatened species. The animals would undergo any quarantine and veterinary procedures as required by Australian Quarantine Inspection Services (AQIS) prior to importation, and all necessary post-arrival quarantine protocols. There is no intention to release any of the imported species or progeny into the Australian environment and there would be no transfers to private individuals.

All ARAZPA zoos holding frogs follow the agreed protocols for managing and treating chytrid fungus (Speare, 2001), both at the general level and, in the case of Melbourne Zoo, a specific institutional procedure.

2. Provide information on the taxonomy of the species

Kingdom	Animalia
Class	Amphibia
Order	Anura
Family	Microhylidae
Genus	Dyscophus
Species	antongilii (Grandidier, 1877)
Common name	Tomato frog

3. Describe the current status of the species in its natural range

This species of Malagasy Tomato Frog (there are three) is restricted to a less than 10 sites on the east coast of Madagascar. It is not listed by the IUCN, but is on Appendix 1 of CITES due to heavy collecting pressure (CITES, 2003).

4. Describe the current status of the species in Australia

This species is not currently found in Australia.

5. Assess the likelihood that the species could establish in the Australian environment, and Pest History

• Habitat Requirements
• Behavioural Characteristics
• Reproductive Characteristics
• Physical Characteristics

We have been unable to source any references or information recording instances this species escaping from captivity or having established a feral population.

The Tomato Frog has not been recorded as carrying any specific diseases. It is likely to be susceptible to the usual range of internal parasites and bacterial and fungal infections that can affect all amphibians.

This species is not difficult to keep in captivity and has been bred in captivity (de Vosjoli & Mailloux, 1990; Mattison, 1993).

Habitat Requirements

This species occurs on the east coast of Madagascar, which is subjected to rainfall throughout the year and constant temperatures of 25-30°C. The frogs occur amongst a range of vegetation on the forest floor, but usually close to or in shallow water (Duellman & Trueb, 1986; Glaw & Vences, 1992).

Although this habitat and climate would be matched by some areas in coastal north-east Queensland, this is a long way from Melbourne Zoo, which is the only institution planning to hold this species. It is highly improbable that, even in the unlikely event of an escape, that frogs would be able to survive and breed due to the cooler and wetter conditions that they would encounter around Melbourne.

Behavioural Characteristics

The Tomato Frog is a sedentary species, rarely moving far from preferred sites in the forest or close to shallow pools. It does not climb and is not a good swimmer, preferring to walk or slowly hop. During any lengthy dry periods, these frogs will tend to burrow into loose surface soil and leaf litter, emerging after rain (Glaw & Vences, 1992; Mattison, 1993).

A range of small insects are eaten. This is a quiet and inoffensive species, although frogs can inflate themselves if disturbed and produce a whitish skin secretion that can cause an allergic reaction in some people (Glaw & Vences, 1992).

Reproductive Characteristics

Males usually call at night, sometimes during the day, from swamps, shallow pools and sewage ditches, more often after heavy rain. A clump of spawn contains 1,000-1,200 small black-white eggs, deposited on the water surface. Tadpoles hatch after 36 hours and are filter feeders. Metamorphosis commences after about 45 days and the emerging froglets are brown-yellow, rather than red (de Vosjoli & Mailloux, 1990; Glaw & Vences, 1992; Mattison, 1993).

Physical Characteristics

Females reach 105mm in length, whilst males rarely exceed 65mm. The back is orange-red and the ventral surface yellowish, sometimes with black spots on the throat. The skin on the back is smooth, with two dorso-lateral folds (Glaw & Vences, 1992).

6. Assess the consequences of the species becoming established in the Australian environment

In the event that this species became established in Australia the main impact would be mainly on small invertebrates. These frogs no real threat to people, buildings or the environment generally, although they may compete with native frogs for food or access to shallow water bodies.

7. Provide information and results of any other similar assessments undertaken on the species (e.g. assessments of the species by the Vertebrate Pests Committee or any relevant State or Territory Agency)

This species has not been assessed by the VPC.

8. Provide information on all other relevant Commonwealth, State and Territory legislative controls on the species and the assessment upon which these controls were based

As this species is only intended for holding at Melbourne Zoo, it would be assessed against and listed under the Victorian Catchment & Land Protection Act.

9. Assess what conditions or restrictions, if any, could be applied to the import of the species to reduce any potential for negative environmental impacts

All amphibians entering Australian zoos from overseas are currently subjected to a range of stringent health import conditions, which have just being reviewed and updated by Biosecurity Australia-Australian Quarantine Inspection Service. These requirements, in concert with the high level of management in ARAZPA zoos, have resulted in no escapes of exotic frogs into the Australian environment. The current proposal calls for these frogs to be subject to ongoing permanent quarantine and strict management in a single ARAZPA institution.

In view of these factors, it is recommended that this species be added to the list of species approved for import, on the conditions that it is only held in high security display and research facilities and not transferred to private individuals.

10. Provide an overall assessment on the potential impacts of importing the species, include both the potential impacts of the particular import that is proposed and the potential impacts of the species per se (i.e. the potential impacts on the environment should the specimen(s) ever be released from effective human control)

It is not intended that these frogs ever be released from quarantine control and they would always be maintained in an ARAZPA zoo. In the event that they did escape and potentially become established, the likely environmental impact would be low:

• Unlikely to establish and breed due to distances between holding zoo and suitable habitat.
• Very small numbers are intended for importation and holding.
• This and similar species have been held in captivity, both in zoos and private collections, in Europe and the USA for many years with no records of escapes or establishment.
• The frogs are brightly coloured, which would aid them being seen should they escape.
• The frogs pose no threat to humans or the general environment, and, given the numbers of frogs involved, a relatively low risk to native Australian fauna.
• These frogs are very sedentary and do not move great distances in nature.
• This is not a venomous species.

References

CITES (2003) Appendices to the CITES Convention. Downloaded from www.cities.org on 9 October, 2003.

De Vosjoli, P. & R. Mailloux (1990) Breeding on thin ice: the husbandry and propagation of the Malagasy Tomato Frogs, Dyscophus antongilii and D. insularis. In, Uricheck, M.J. (ed.) Proceedings of the 13th International Herpetological Symposium on Captive Propagation & Husbandry, Western Connecticut State University; pp. 181-93.

Duellman, W.E. & L. Trueb (1986) Biology of Amphibians. McGraw-Hill Publishing Company & John Hopkins University Press, Baltimore.

Glaw, F. & M. Vences (1992) A Field Guide to the Amphibians and Reptiles of Madagascar. M. Vences, Cologne.

Mattison, C. (1993) Keeping and Breeding Amphibians. Blandford Press, Poole.

Speare, R. (2001) Developing management strategies to control amphibian disease: decreasing the risks due to communicable diseases. School of Public Health & Tropical Medicine, James Cook University, Townsville.

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