Notes on the observation of a 
deformed D. tinctorius found 
in French Guiana

David Massemin
Christian Marty

French Guiana is located on the North-East coast of South America, at a latitude between 2° and 6°North. Its climate is equatorial and the Neotropical rainforest covers more than 98% of the area (de Granville, 1988). One hundred and seven amphibian species are known from here (Lescure and Marty, in press). The family Dendrobatidae is represented by 7 species, including Dendrobates tinctorius. The aim of this note is to report the first finding in the wild of a deformed 'monster' specimen of this species in French Guiana. Amphibian malformations are reported from North America (Ankley et al. 1998; Gardiner and Hoppe 1999) but there is no mention of such phenomena in South America and more particularly in Neotropical rainforests (Jeffray A. Jundt, Coordinator to the North American Reporting Centre for Amphibian malformations, pers. com).

On the morning of the Nov. 20^th 1999, at the beginning of the rainy season, David Massemin found one specimen of Dendrobates tinctorius alive with obvious anatomical malformations. The animal was located at about 15 kilometres Northwest of the city of Saint Georges de l'Oyapock, which is on the Brazilian border. There, the forest is intact and uninhabited and without human activity, except hunting. Before being captured, the frog was observed with more than ten other Dendrobates tinctorius that were roughly the same size. The specimen had a third hind limb (fig. 1) that appeared to not be functional because it 'shuffled' without any active movement. The frog was caught and measured alive with callipers, which showed a snout-vent length of 31·7mm. It was kept in captivity in a vivarium for a few weeks during which time it was seen feeding on small insects. Finally, we took x-ray photographs of it.

On the pelvic girdle and hind leg radiography we saw that the supernumery leg is implanted on the right hip, just above the normal leg, at the level of the acetabulum area. This supplementary posterior member is as long as the other legs (35mm). From the articulation between tibia, fibula and tarsus, there are two opposed feet that begin free from the first phalanges. Those feet are opposed in a symmetric axis as are right and left normal feet. Their first toes are contiguous. On the supernumerary member, only the feet skeleton is divided. Up to now, we have no clues as to the cause of those malformations.

Acknowledgments
Thanks to Michel Blanc who maintained the captive animal, to Dominique Frenay for the radiography and to Christiane Massemin who helped us to translate the notes.