New Discovery: Fang-Bearing Tadpoles of the Vampire Flying Frog (Rhacophorus vampyrus)

The year 2011 has barely begun, but it is already supplying amphibian enthusiasts with exciting news items.  One of the most surprising is the discovery that the tadpoles of the newly-described Vampire Flying Frog, Rhacophorus vampyrus, sport hard, sharp fangs…a previously unknown amphibian adaptation.

A Surprise in the Treetops

Biologists from Australia, Vietnam and the USA (North Carolina Museum of Natural Sciences) uncovered the new frog and its odd tadpoles while surveying montane forest canopies on the Langbian Plateau in southern Vietnam.  Their findings, published in the journal Zootaxa (please see article below), have left herpetologists wondering just why tadpoles might need such odd mouthparts…certainly not to puncture veins, as their common name suggests!

The unique tadpoles seem to hatch from eggs deposited in water-filled tree hollows high above the ground, but beyond that we know nothing of their natural history.

Tadpole Teeth

Tooth structure is an important means of identifying tadpoles, especially given that so many are difficult to distinguish by eye.  Most bear circular rings of rasping teeth or beak-like mouthparts; those of the Vampire Flying Frog sport a pair of hard, sharp black fang-like structures that arise from the lower jaw.  While Horned Frog and some other tadpoles are highly carnivorous, none have evolved such specialized dentition.

The New Frog and its Relatives

The Vampire Flying Frog is classified within the family Rhacophoridae, a widespread group of 319 largely arboreal frogs (please see photos for examples).  Several, including Wallace’s Flying Frog and the Golden Treefrog, have evolved the ability to glide (please see drawing) and are popular in the pet trade.

As of now, the Vampire Treefrog is known only from the Bidoup-Nui Ba National Preserve in southern Vietnam.  In common with other Vietnamese amphibians living at high altitudes, it is threatened by the expansion of coffee farms.  Its discovery brings the number of known amphibians to 6,138, many of which have been found only in the past 2 decades.