Giant barred-frog
Giant barred frog. Photo: Steve Wilson
Common name: giant barred frog
Scientific name: Mixophyes iteratus
Family: Myobatrachidae (Australian water frogs)
Conservation status: This species is listed as Endangered in Queensland (Nature Conservation Act 1992) and nationally (Environment Protection and Biodiversity Conservation Act 1999). It is ranked as a medium priority under the Department of Environment and Resource Management Back on Track species prioritisation framework.
Description
A very large frog up to 115 mm with a pointed snout and well developed hind legs. The dorsal surface is dark olive to black, with darker blotches and an irregular dark vertebral band commencing between the eyes and continuing posteriorly. A dark stripe runs from the snout, through the eye and above the tympanum, terminating at a point above the forelimb.
There are irregular dark spots or mottling on the flanks. The limbs have a series of dark and pale crossbars of similar width. The hidden part of the thigh is black with a few large, yellow spots. The ventral surface is white to yellow with fine mottling on the chin. The pupil is vertical, while the iris is pale silvery-white to pale gold above, darker in the lower portion. The fingers lack webbing, while the toes are fully webbed, with only the last two joints of the fourth toe free. The outer metacarpal is poorly developed, the inner metatarsal tubercle is well developed, but only half as long as first toe. The skin is finely granular above, smooth below. The tympanum is distinct (Barker et al. 1995; Cogger 2000; Straughan 1968).
Habitat and distribution
This species occurs along shallow rocky streams in rainforest, wet sclerophyll forest and farmland from 100 to 1000 m (Covacevich and McDonald 1993) or deep, slow moving streams with steep banks in the lowlands (H. Hines pers.comm.).
The giant barred frog occurred along streams in the coastal ranges and lowlands from Belli Creek near Eumundi, in south east Qld to Warrimoo in mid-east NSW (26° 31'S, 152° 49'E - 33° 43'S, 150° 36'E) (Hines et al. 1999).
This species has experienced significant population declines in the north and south of its range during the late 1980's (Ingram and McDonald 1993; Mahony 1993). In south-east Queensland it is currently known from scattered locations in the catchments of the Mary, Upper Stanley, Caboolture and Coomera Rivers (Hines et al. 1999). Recent surveys have failed to locate the species in historical sites in the Bunya Mountains, Conondale Range, Cunningham's Gap and Main Range (Hines et al. 1999). It is found in Conondale, Bunya Mountains, Main Range, Lamington National Parks as well as Delicia Road and Neurum Creek Conservation Parks.
Latitude: Between 26&186; 31' and 33&186; 43'
Longitude: Between 151&186; 29' and 153&186; 15'.
Life history and behaviour
The giant barred frog call is a deep guttural grunt (Barker et al. 1995). Males call from crevices under rocks, banks or overhanging tree roots (Cogger et al. 1983; Straughan 1968).
Relatively little is known regarding the reproductive biology of this species. Amplexus is axillary, but egg deposition has not been documented. A gravid female was found to carry 4184 eggs with a mean diameter of 1.6 mm. Larvae are present throughout the year and probably over-winter. Laboratory reared metamorphs reach 28-30 mm. (Hero & Fickling 1996; Straughan 1966).
The tadpole has not been formally described. They are large and of lotic form, with suctorial mouth, muscular tail and reduced fins. Other species of Mixophyes are characterised by the presence of at least three upper rows of labial teeth and a complete papillary border surrounding the mouth disk (Davies 1991; Watson and Martin 1973).
Threatening processes
The causes of this and similar declines in other frogs of south-eastern Queensland remain unknown. As declines have occurred in undisturbed and disturbed rainforest, it is unlikely to be the result of habitat disturbance, but other possible causes have not been examined for this species.
Suspected threatening processes include:
- Habitat loss through clearing, timber harvesting and urban development.
- Degradation of water quality and riparian vegetation arising from logging, grazing, weed invasion and pollution.
- Predation by feral pigs.
- Disease.
Current research is examining the possibility that a disease may have caused the decline of this species (Berger et al. 1999). Information on disease investigations and management can be located at the James Cook University web site.
Recovery actions
The recovery plan for the stream frogs of South-east Queensland makes the following management recommendations:
- Conduct regular, long-term population monitoring and assessments of likely habitat.
- Conduct research to: further develop husbandry and translocation techniques; investigate the genetic structure of populations; and investigate the role of disease.
- Develop protocols addressing frog handling and contingency planning.
- Develop prescriptions for effective habitat protection and management.
- Develop and distribute a range of materials to increase public education and information.
Related information
Hines, HB and the South-east Queensland Threatened Frogs Recovery Team 2002. Recovery plan for stream frogs of South-east Queensland 2001-2005. Report to Environment Australia. Canberra. Queensland Parks and Wildlife Service, Brisbane.
Tyler, M.J. 1997. The Action Plan for Australian Frogs, Environment Australia, Canberra.
Tyler, MJ and Knight, F 2009. Field guide to the frogs of Australia. CSIRO Publishing, Collingwood Victoria.
References
Barker, J, Grigg, GC and Tyler, MJ 1995. A Field Guide to Australian Frogs. Surrey Beatty & Sons, Chipping Norton, NSW.
Cogger, HG 2000. Reptiles and Amphibians of Australia. Reed New Holland, Sydney.
Cogger, HG, Cameron, EE & Cogger, HM 1983. Zoological Catalogue of Australia. Vol. 1 Amphibia and Reptilia. Australian Government Publishing Service : Canberra.
Covacevich, JA and McDonald, KR 1993. Distribution and conservation of frogs and reptiles of Queensland rainforests. Memoirs of the Queensland Museum 34(1):189-199.
Davies, M 1991. Descriptions of the tadpoles of some Australian limnodynastine leptodactylid frogs. Transactions of the Royal Society of South Australia 115: 67-76.
Hero, JM and Fickling, S 1996. Reproductive characteristics of female frogs from mesic habitats in Queensland. Memoirs of the Queensland Museum 39: 306.
Hines, H, Mahony, M and McDonald KR 1999. An Assessment of Frog Declines in Wet Subtropical Australia. In Campbell, A (ed), 'Declines and Disappearances of Australian frogs'.(Environment Australia, Department of the Environment and Heritage: Canberra). 234 pp.
Ingram, GJ and McDonald, KR 1993. An update on the decline of Queensland's frogs. Pp 297-303 In Lunney, D. and Ayers, D. (eds), Herpetology in Australia. A diverse discipline. (Royal Zoological Society of New South Wales: Mosman). 414pp.
Mahony, MJ 1993. The status of frogs in the Watagan Mountains area of the Central Coast of New South Wales. Pp. 257-264 In Lunney, D. and Ayers, D. (eds), Herpetology in Australia. A diverse discipline. (Royal Zoological Society of New South Wales: Mosman). 414pp.
Straughan, IR 1968. A taxonomic review of the genus Mixophyes (Anura, Leptodactylidae). Proceedings of the Linnean Society of N.S.W. 93:52-59.
Watson, GF, and Martin, AA 1973. Life history, larval morphology and relationships of Australian leptodactylid frogs. Transactions of the Royal Society of South Australia 97 : 33-45.
Last updated 26 July 2011