Rheobatrachus silus
Copyright © Hal Cogger
Distribution map
Distribution Map of Rheobatrachus silus
Copyright © Hal Cogger & Frogs Australia Network
Status
IUCN Classification:
Extinct
(International Union for Conservation of Nature)
Bioregion occurrence:
(this is not a distribution map)
State occurrence:
Links
- Southern Gastric Brooding Frog
Queensland Environmental Protection Agency page on Rheobatrachus silus
Search on this family or genus
Rheobatrachus silus
Family: Myobatrachidae
Common names: Southern Gastric Brooding Frog; Gastric Brooding Frog; Southern Platypus Frog
Description: This frog varied from black to olive brown on its back with darker blotches. The arms and legs had dark barring above and were yellow underneath. There was a dark streak from the eye to the base of the arm. The belly was smooth and white. The toes were webbed. The toes (included the webbing) and fingers were pale with brown flecks. The skin on the back was finely granular. The last individual was seen in the wild in September 1981.
Size: 50 mm
Habitat: This frog lived in wet sclerophyll forests around rocky mountain streams. This aquatic species often hid under rocks in the water.
Call: Sounded like "eeeehm…eeeehm" with an upward inflection.Call available in 
Windows Media or 
Quicktime audio. Recording Copyright © Keith McDonald.
Breeding: Males called from the water's edge in summer. This frog's breeding habits were very unique - it was a gastric brooder. The female swallowed the eggs after they had been fertilized and the tadpoles developed in her stomach. The froglets were eventually regurgitated.
Eggs: Were large and fertilized by the male before the female swallowed them.
Tadpoles: Developed by feeding on their large egg yolks, in their mother's stomach.
Similar species: This species can be distinguished from Rheobatrachus vitellinus by its distribution, colour pattern and mottled webbing.
Conservation Information
Suspected threatening processes
- Inappropriate catchment management, including degraded water quality
- Disease/pathogens (e.g. chytrid fungus, viruses)
Population size: An estimate of the total number of adults present in the species entire range is 0-1000 individuals. Some factors affecting population size and distribution are known, but 1 or more major factors are unknown.
Population trend in Australia over the past 50 years: Population size known to be decreasing.
Knowledge of population trend in Australia: Nation-wide monitoring, but not with statistical sensitivity.
Population concentration: Majority concentrates at more than 25 locations. (e.g. the number of sites in which individuals group together either seasonally, such as breeding sites, or they may occupy discrete habitat patches within the broader landscape, such as discrete water bodies or drainage units.)
Ongoing management activities in Australia: Management mostly related to enforcement of conservation laws.
Reproductive potential for recovery: The average number of eggs deposited per adult female per year is 1-50 eggs/female/year. Minimum age at which females are known or suspected to first reproduce is 2-3 years.
Range size in Australia: The size of the geographic area over which the taxon is distributed: < 100 km².
Distribution trend: Area occupied has declined by 75-100%. (This is an estimate of change in the portion of the total range that is occupied or utilised; it may not equal the change in total range.)
Knowledge of distribution in Australia: Distribution is well known and occurrence can be accurately predicted throughout the range.
References
Barker, J., G.C. Grigg and M.J. Tyler. 1995. A Field Guide to Australian Frogs. Surrey Beatty & Sons: Chipping Norton.
Cogger, H.G. 2000. Reptiles and amphibians of Australia. Reed Books: Sydney.
Robinson, M. 2002. A Field Guide to Frogs of Australia. Australian Museum/Reed New Holland: Sydney.
Swan, G. 2001. Green Guide to Frogs of Australia. New Holland: Sydney.