The Southern gastric-brooding frog is known to few as the Platypus frog, however, many of us know it as the `frog that gives birth through mouth’.
It is a fact that following external fertilization by the male, the female would swallow the fertilized eggs. It was never observed and hence not clear whether the eggs were laid on the land or in the water. While inside the female, the young ones developed into tadpoles and subsequently into froglets after which they were expelled into the mouth and then crawled out from the protective world to the real world. During this entire period (ranging between 6 to 7 weeks) when the female held the fertilized eggs inside her stomach till the froglets were expelled, the female would not eat anything and her digestive process would automatically shut down. The only source of respiration for the female would then be the gas exchange through her skin.
The Southern gastric-brooding frog was a native of Australia and was first discovered in 1972 (reported in 1973) in pristine rainforest in the ranges in south east Queensland, where it occupied a small range of less than 1,400km2. They were neither strictly nocturnal nor diurnal and although good swimmers, they were not very active and stayed still (floating or drifting) for hours in the water. Small insects from both land and water were the main feed for these frogs whereby the prey was caught with the tongue and forelimbs were then used to manoeuvre the prey into the mouth. While the soft-bodies insects were eaten at the water surface, the harder ones were consumed underwater.
In addition to the unique style of reproduction, another interesting fact associated with the Southern gastric-brooding frog was that the females were larger than the males.
The last of the species was seen in 1981, while a captive specimen in a laboratory died in 1983. Now believed to be extinct, the cause/s of the gastric-brooding frog’s extinction is however not clearly understood, although many attribute the extinction to degradation, pollution, loss of habitat loss and some fungal infection. In fact, it is now established that the southern gastric brooding frog was one of the first of a series of amphibian extinctions that occurred within Queensland around the late 1970s until the early 1990s.
The only other gastric-brooding frog was the Northern gastric-brooding frog, which too is considered extinct.