External morphology, buccopharyngeal anatomy and development rate of the tadpoles of two Asian Ranidae (Amphibia: Anura), Hylarana humeralis (Boulenger, 1887) and Hylarana leptoglossa (Cope, 1868)

Abstract

Descriptions of external morphology and buccal features are provided together with ontogenetic data of the tadpoles of Hylarana humeralis and Hylarana leptoglossa. These tadpoles are compared to known tadpoles of the genus Hylarana as defined by recent phylogenetic analyses here grouped in subgenera as previously proposed. The content of the subgenus Humerana is re-evaluated. The occurrence of three relevant larval characters (keratodont row formula, presence of long marginal papillae on the lower labium and presence of glands) is examined among the different subgenera and clades inferred from molecular phylogenies to assess their homogeneity regarding larval morphology. The smaller eggs of H. humeralis hatch into larger tadpoles and subsequently larger adults than the bigger eggs of H. leptoglossa. The reasons for the observed shift in size during stage 25 for these two species are briefly discussed in the light of literature data.

Keywords:

• Ranidae
• tadpoles
• morphology
• morphometry
• growth