Aquatic biologists at the Academy first began breeding Asian horned frogs (Megophrys nasuta) in captivity one year ago, and have now successfully raised over a dozen tadpoles into young frogs. Even after a year, around 40 of the frogs are still tadpoles, but more metamorphose every week, and seem to be in excellent health. The young frogs and tadpoles are being raised behind the scenes in the aquarium’s amphibian holding room.

Very few zoos and aquariums have been able to breed this species successfully, so our biologists have been learning as they go. One of the discoveries they made was that the size of an egg clutch can actually be as large as 1,400 eggs – a figure much higher than the popular literature suggested.

Native to the rainforest floors of Indonesia, Malaysia and Singapore, these frogs are not currently threatened in the wild, but are vulnerable to habitat destruction and exploitation by the pet trade industry. At the Academy, several adult Asian horned frogs can be seen on the Borneo level of the rainforest exhibit, blending into their leafy surroundings.

Photos: (c) Brian Freiermuth/California Academy of Sciences

Left: The much smaller male holds on to the large female in amplexus, the typical grasping behavior many frogs engage in prior to egg laying and fertilization.
Center: Tadpoles have upward turned mouths that allow them to filter feed at the water’s surface.
Right: A newly metamorphosed froglet still has some tail left, but already has tiny projections over the eyes like its adult counterparts.