Giant Tadpole and Delayed Metamorphosis of Pseudis platensis Gallardo, 1961 (Anura, Hylidae)

FABREZI, MARISSA; QUINZIO, SILVIA INÉS; GOLDBERG, JAVIER

JOURNAL OF HERPETOLOGY

SOC STUDY AMPHIBIANS REPTILES

Año: 2009 vol. 43 p. 228 - 243

0022-1511

Pseudis platensis, like Peudis 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 developmnet 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 similarities 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 charcaterize 13 ontogenetic stages as follows: four for prometamorphic larval morphologies, eigth 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 uniques features not reported for other anurans and offers a model to study developmental and evolutionary aspects of anuran metamorphosis.