Is it heterochrony? Populational differences in tadpole of Corythomantis greeningi Boulenger, 1896 (Anura: Hylidae)

Corythomantis greeningi is a hylid widely distributed in the xerophilic and sub-humid morphoclimatic regions of northeastern Brazil. The morphology of C. greeningi tadpoles were described from specimens collected in the Bahia, however, we observed some differences in morphology of individuals from Piauí, northeastern Brazil. The tadpoles were collected during the 2019 rainy season and 14 individuals were used to compare the larval characters. We observed differences in external, internal oral and chondrocranial morphology in relation to specimens previously described, especially in oral disc, number and shape of oral cavity papillae and some chondrocranium structures, suggesting a heterochrony in the development of the species. Further studies involving a greater number of tadpoles at different stages, combined with genetic, acoustic, and morphological factors of adult may establish the variation degree of C. greeningi in different regions of northeastern Brazil.