Different pathways are involved in the early development of the transient oral apparatus in anuran tadpoles (Anura: Leiuperidae)

VERA CANDIOTI FLORENCIA; HAAD MARIA BELEN; BALDO DIEGO

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 vol. 104 p. 330 - 345

0024-4066

The oral apparatus of anuran tadpoles is a unique structure composed of soft and keratinized parts surrounding the mouth. Among the many variations, a common oral apparatus involves a dorsal gap in the marginal papillae, keratinized  jaw  sheaths, and  two  upper  and  three  lower  rows  of  labial  teeth.  In  Leiuperidae,  besides  this generalized morphology, four configurations are distinguished by the arrangement of the lower marginal papillae and  the  number  of  lower  tooth  rows.  Study  of  the  early  oral  ontogeny  in  12  species  representing  these  five configurations shows variations in the development of the lower marginal papillae and the third lower labial tooth row. Similar configurations may result from similar pathways (e.g. Physalaemus cuvieri group and Pseudopaludicola falcipes) or different pathways (e.g. generalized oral discs of Pleurodema and Physalaemus). Different oral configurations may result from overlapping trajectories ending at different stages (e.g. Physalaemus riograndensis and Ph. biligonigerus) or different trajectories (e.g. Ph. henselii and Ph. gracilis). Further studies are needed to interpret  the  role  that  heterochrony  has  played  in  evolutionary  change  within  this  family.  The  unsuspected variation occurring in this transient structure highlights its evolutionary potential and might be insightful in studies of anuran phylogenies that are largely based on adult characters.