A living incubator
In the slow-moving, murky waters of the Amazon, the Surinam toad (Pipa pipa) engages in one of the most unusual reproductive strategies in the animal kingdom. The process begins when a male attracts a female with a series of sharp, metallic clicking sounds, produced by snapping the hyoid bone in his throat. He then clasps her in a mating hold called amplexus. The pair performs a series of aquatic somersaults that can last for more than 12 hours. While upside-down, the female releases between 60 and 100 eggs. As the pair rotates back to an upright position, the male fertilizes the eggs and gently pushes them onto the female’s back.
The female's back skin, which has become thick and soft, allows the eggs to adhere and sink into its surface. Over the next few days, her skin grows up and around each individual egg, forming a honeycomb-like group of pockets. Each egg becomes fully enclosed in its own dermal cyst, where it is protected and incubated. This method completely bypasses a free-swimming tadpole stage. The entire larval development happens within the safety of the mother's back.