Tuesday, 20 September 2011

Turtle Frog

Turtle frog, photo shot at the suburbs of Perth, Australia
Turtle frog at Northeastern suburbs of Perth, Australia.
Credit: "Myobatrachus gouldii" by Paul J. Morris at
Flickr Licensed under
Creative Commons Attribution-Share Alike 2.0.
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Myobatrachidae
Genus: Myobatrachus
Species: Myobatrachus gouldii
Conservation Status: Least Concern (Not threatened)
Common Names: Turtle Frog

As implied by its common name, the turtle frog is an odd looking frog, that has a body shape reminiscent of a turtle with no shell.

M. gouldii is a Western Australian frog and the sole representative of the genus Myobatrachus. The species is a common sight in the area between Geraldton and Fitzgerald River in the Perth region of Western Australia.

The turtle frog is usually found beneath logs and rocks in sandy soil, open woodlands, dense scrubs in sand hill and places where the soil is made of leached grey sand. Turtle frogs generally avoid hard substrates and drainage channels.

The estimated altitudinal range of the species is from 0 to 600 m, above sea level.

The turtle frog has a round, turtlish and bulbous body and a small head with reduced eyes. They grow to be about 5 cm (~2 in.) long.

Their color varies from grayish to brown and their bellies are smooth and grey with brown spots. The skin on the back is very smooth and shiny, with fine granulations.

Turtle frogs are highly adapted to the semi arid environment they usually inhabit. Although small, the limbs are strong and muscular allowing the species to burrow into the sand. Contrary to most other frogs, they dig forwards and not backwards, like turtles do.

Interestingly, turtle frogs skip the tadpole stage. The embryos undergo the entire developmental process while still inside their eggs. Hatchlings are fully developed and look like miniature adults.

A turtle frog out of its burrow
Turtle Frog
Credit: By Paul J. Morris (Myobatrachus gouldii)
[CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)],
via Wikimedia Commons

Turtle frogs feed exclusively on termites and can eat up to 400 termites at a time. This is why they inhabit areas associated with termite colonies.

Mating occurs from September to February, usually after a heavy rain that triggers the turtle frogs to come up to the surface. Males call for females and then the couples dig a deep burrow and remain together until autumn. This is one of the rare instances of extended pairing in the frog kingdom. Breeding occurs within the burrow several months later.

Females lay eggs in clutches, each containing 9-38 eggs. The eggs are laid 0.5-1.5 m underground and are quite big, amongst the biggest ones laid by Australian frogs, with an average diameter of 6 mm (max 7.5).

As aforementioned, the embryo goes through its entire development in the egg. The young turtle frogs emerge as small, fully-formed frogs.

Conservation Status
For the past five decades, the species' overall population appears to have a stable or perhaps a slightly increasing trend. Turtle frogs have no known threats and are distributed in an area with very little human disturbance.

The species is listed by the IUCN as of least concern and appears to have a bright future.

Other interesting facts about the turtle frog
- The species is named after John Gould(1804 -1881), a famous English ornithologist and bird artist.
- Turtle Frogs are closely related to the Sandhill Frogs and Forest Toadlet and share direct-developing young and forwards-burrowing habits.

References & Further Reading
- Barker, J., Grigg, G. C., and Tyler, M. J. (1995). A Field Guide to Australian Frogs. Surrey Beatty and Sons, New South Wales.
- Cogger, H.G. (1992). Reptiles and Amphibians of Australia. Reed Books, New South Wales.
- Tyler, M.J., Smith, L.A., and Johnstone, R.E. (1994). Frogs of Western Australia. Western Australian Museum, Perth.
- Roberts, J. (1981). Terrestrial Breeding in the Australian Leptodactylid Frog Myobatrachus gouldii (Gray) Wildlife Research, 8 (2) DOI: 10.1071/WR9810451
- Gray, J.E. 1841. Description of some new species and four new genera of reptiles from Western Australia, discovered by John Gould, Esq. Ann. Mag. Nat. Hist. Ser. 7 Vol. 42 pp. 86-91
- Jean-Marc Hero, Dale Roberts 2004. Myobatrachus gouldii. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>.