Nature’s Oddity: Scientists Discover Unusual Frog That Breeds Upside-Down

A study reveals unique breeding behaviors in the Andamanese Charles Darwin’s frog, including upside-down egg-laying and intense male competition. The species faces habitat challenges, breeding in unnatural sites like trash, underscoring urgent conservation needs.

Researchers from the University of Delhi and Zoological Survey of India, Harvard University, and the University of Minnesota have discovered a unique breeding behavior in a species of frog endemic to the Andaman Islands of India. In a new study published in the Harvard Museum of Comparative Zoology’s journal Breviora, the scientists describe the frog’s unique combination of reproductive behaviors.

The Andamanese Charles Darwin’s frog, Minervarya charlesdarwini, belongs to the family Dicroglossidae, a large radiation of Asian frogs that comprises over 220 species. Charles Darwin’s frogs naturally breed as well as deposit terrestrial eggs above the water surface on the inner walls of water-filled tree cavities or root buttresses. Hatchlings then drop into the water below and complete their development through a free-swimming tadpole stage.