External Morphology, Chondrocranium, Cranial Muscles, and Buccopharyngeal Features of Tadpoles of Pleurodema thaul (Anura: Leiuperidae): a Comparison with P. bufoninum

Abstract

This article describes the external and buccopharyngeal morphology, chondrocranium, and cranial muscles in tadpoles of Pleurodema thaul from Argentina. Further comparison was made with larvae of other Pleurodema species, particularly P. bufoninum. The larvae of P. thaul possess: (1) tooth row formula 2(2)/3(1), (2) single to double row of marginal papillae with wide rostral gap, (3) presence of long processus pseudopterygoideus, (4) pars alaris and pars corpora of the cartilago suprarostralis joined by both proximal and distal connections, and (5) larval processus oticus present. In the light of the available evidence, the larvae of Pleurodema are characterized by (1) medium size (total length = 35.4–48.7 mm); (2) medium-sized tail (0.63 times of total length); (3) rounded snout; (4) nostrils closer to the eyes than to the snout; (5) vent tube opening medial; (6) tail tip rounded; and (7) oral disc subterminal with angular constrictions and rostral gap present. In Leiuperidae, the cartilaginous distal connection between pars alaris and pars corpora of the cartilago suprarostralis is present only in Pleurodema. In addition, all Pleurodema studied to date have processus pseudopterygoideus (shared with Eupemphix and Physalaemus marmoratus). Finally, within Pleurodema, the larval processus oticus is present only in P. thaul and P. bufoninum.