Scientists from Boston University have discovered that the Yellow Treefrog (Dendropsophus ebraccatus), a native to Panama and other regions throughout Central America, is able to lay its eggs on land or in water. So far, no other egg-laying vertebrate is capable of such reproductive flexibility. According to researchers Justin Touchon and Karen Warkentin, the Yellow Treefrog may "represent an intermediate stage in the evolution of terrestrial reproduction, combining a retained ancestral capacity for aquatic development with a derived ability for terrestrial oviposition and development".

The research team examined several ponds where Yellow Treefrogs breed. In areas where the ponds were exposed with little vegetation and shade, the frogs laid the majority of their eggs (76 percent) in water. In locations where there was sufficient shade and vegetation covering the pond, the frogs deposited their eggs on vegetation hanging over the pond. When the eggs hatched, the young tadpoles dropped from the leaves to the water below.

The ability of the Yellow Treefrog to lay eggs in both aquatic and terrestrial environments may enable it to better adapt to fluctuations in climate and habitat alteration.

Find out more:

• Reproductive Mode Plasticity: Aquatic and Terrestrial Oviposition in a Treefrog (PNAS)
• Reproductive Plasticity Revealed (Science Daily)

Photo © Justin Touchon and Karen Warkentin / Boston University. Mating yellow treefrogs (Dendropsophus ebraccatus) laying egg larvae in water. The egg masses can be at the water surface and under water.