GOLDBERG Francisco Javier
Giant tadpole and delayed metamorphosis of Pseudis platensis Gallardo, 1961 (Anura, Hylidae)
FABREZI, M.; QUINZIO, S.; GOLDBERG, F.J.
JOURNAL OF HERPETOLOGY
Año: 2009 vol. 43 p. 228 - 243
Pseudis platensis, like P. paradoxa, is a neotropical aquatic frog with a giant tadpole. Despite being one of the few anuran species whose larvae grow larger than adults, knowledge of its larval development is limited to prometamorphic stages. This study describes qualitative and quantitative variation through P. platensis larval development, including descriptions of various traits (lateral line, oral disc, vent tube, limbs) and their transformations during metamorphosis. We found equivalences with the development of other anurans at larval stages up to the end of prometamorphosis, but not with their metamorphic stages. For this species, we described key features to characterize thirteen ontogenetic stages as follows: four for prometamorphic larval morphologies, eight stages covering metamorphic changes, and one defining the posmetamorphic adult stage. At the end of prometamorphosis, tadpole body size in P. platensis is similar to adult size, but the tail shows extra development. Unlike most anurans, the disappearance of two larval traits (i.e. vent tube and tail) is delayed until later in metamorphosis. Larval development of P. platensis exhibits unique features not reported for other anurans and offers a model to study developmental and evolutionary aspects of anuran metamorphosis.