Characteristics of the Family Myobatracidae Australian Frogs

Frogs belonging to the Myobatrachidae family are unique and are only found in Australia, New Guinea, and Tasmania. This family includes up to 100 species that are both currently living and extinct. All species of frogs of this family are terrestrial and can be found living in a diverse range of climates which include deserts, where they burrow underground, to mountain streams. The exception for this family is habitation of trees as there are no types of tree frogs found in the Myobatrachidae family.

Members of the Myobathachidae family are quite different from that of other frog families. Many of the characteristics are found no where else and are the best way to identify these types of frogs from others. Characteristics of frogs belonging to the Myobatrachidae family include a cartilaginous sternum, absence of rib bones, unusual forms of parental care given to the young, and, in the case of the burrowing species, the habit of burrowing head first.or by using their hind feet like spades for digging. The color and sizes of these frogs varies from species to species. Depending on the specific habitat of the frogs, the body type may be short and round with short legs or elongated with long legs.

Location of egg distribution and tadpole growth are what set this family apart from other frog and toad families. Eggs are often layed with out a water source and tadpoles often develop without the need to eat and simply rely on the absorption of their yolk sack.

The most unusual members of this family are the gastric brooding frogs. These females of the species actually swallow their own fertilized eggs and allow the eggs to hatch and develop into tadpoles while still inside the female’s stomach.  When the tadpoles metamorphose into froglets, they simply crawl out of the female’s mouth. Unfortunately, both species of gastric brooding frogs, the Southern gastric brooding frog (Rheobatrachus silas) and the Northern gastric brooding frog (Rheobatrachus vitellinus), have not been sighted since the mid 1980s and are listed as extinct species.

Another member of the Myobatrachidae family with an interesting method of raising its young is the hip pocket frog (Assa darlingtoni). Also known as the marsupial frog, female hip pocket frogs lay their eggs on the ground and the male fertilizes them. With the eggs still on the ground, both male and female hip pocket frogs guard the eggs in turn. After the tadpoles hatch from the eggs, the male coats himself with a slimy substance which allows the tadpoles to climb onto his body and crawl into small pockets that are located above each hind leg. The tadpoles carry out the rest of their development in these pockets until they are ready to emerge as froglets. The male can carry up to 6 tadpoles in each pocket and the tadpoles sustain themselves on yolk. These frogs are quite small measuring less than an inch long and are found living in the mountains of North Eastern Australia.

Like other unique animals to Australia and the surrounding countries, the Myobatrachidae family of frogs has evolved its own set of characteristics not found in any other frog family. Unfortunately, these frogs are now competing for food and living space with other frog and toad species that were introduced to Australia. Hopefully, the remaining species of these fascinating frogs will remain in the wild much longer than the highly unsual and greatly missed gastric brooding frogs.