Pipa pipa, or the common Surinam toad, is an amphibian from South America. Like the other species of the Pipa genus, it is a purely aquatic toad. Its body is almost entirely flat and its broad, triangular head has no tongue. As a result, it captures its prey – mainly worms, insect larvae and crustaceans –by suction, by suddenly increasing the volume of its mouth. Unlike most amphibians, its fertilised eggs are not laid in water but become implanted into the female’s back, which swells to envelop them. The embryos then develop for three months in these ‘pockets’ and, since they also metamorphose here, they come out as tiny toads. Antonio Vallisneri senior, a physician and naturalist who lived between the 17th and the 18th century, whose collections formed the core element of our museum, received two specimens of this species from a London correspondent. He dissected them and, having ascertained that the internal anatomy of the reproductive organs was similar to that of the other toads and frogs, he thus refuted the hypothesis, then fashionable, that these animals had the uterus along their backs.
