Southern+gastric+brooding+frog

__ Southern Gastric Brooding Frog __
 * __ Fertilisation: __**
 * Fertilization occurs externally however, development occurs internally.
 * The female lays the eggs in a watery environment where the male is able to fertilise them.
 * After they are fertilized by the sperm, the female swallows them.

__ FANCY FACTS ON THE FROG: __ à The scientific name is //Rheobatrachus silus////.// à Approximately 50mm à Became extinct in the 1980’s. à Breeding activity for the Southern Gastric-brooding Frog occurs between October and December.
 * __ Survival of Embryo __**
 * The Gastric brooding frog female swallowed the eggs after they had been fertilized and the tadpoles developed in female’s stomach (gastric-brooding).
 * The production of hydrochloric acid (digestive fluids) in the stomach of the female is stopped by the hormones produced by the young.
 * The female’s entire digestive system shuts down, which prevents the digestion of the young.
 * In the stomach, the eggs are nourished by absorbed nutrients from the mother. After 6-7 weeks the females give birth to up to 25 young, birth is accomplished by the female widely opening her mouth and dilating her gullet (oesophagus).
 * The young are propelled from the stomach to the mouth, and then hop away.
 * They emerge from the female’s mouth as fully former frogs and after 4 days the digestive tract of the female returns to normal and she recommences feeding.[[image:FrogRheobatrachusSilus.jpg width="265" height="206"]]

__ FERTILISATION: __ à Fertilised externally in a watery environment. Fertilisation is external however the development of the egg is internal. à The female releases the eggs and male will find the female’s eggs then fertilise them by the sperm,. Once they are fertilised the female then swallows the eggs. __ SURVIVAL OF EMBYRO: __ à This is beneficial to the eggs because rather than leaving the eggs to develop alone and unprotected, the young develop internally in the female’s stomach. This mechanism provides protection of the egg from infection and dispersal (scattering) of eggs which reduce the success rate of survive the offspring. à The production of hydrochloric acid (digestive fluids) in the stomach of the female is stopped by the hormones produced by the young. The female’s entire digestive system shuts down, which prevents the digestion of the young. à After 6-7 weeks the females give birth to up to 25 young! This is accomplished by the female widely opening her mouth and dilating her (oesophagus). The young are propelled from the stomach to the mouth and regurgitated, and then hop away already developed. They emerge from the female’s mouth as fully former frogs and after 4 days the digestive tract of the female returns to normal and she recommences feeding.