Reproduction and larval morphology of Adenomera diptyx (Anura: Leptodactylidae) from the Argentinean humid Chaco and Brazilian Pantanal. pp. 1-9.
Abstract. Whereas the external larval morphology of some species of Adenomera has been described, their internal morphology remains poorly studied. In this work, we provide information on the reproductive features and larval morphology of populations of Adenomera from northeastern Argentina and southwestern Brazil, including the first description of the chondrocranium and hyobranchial apparatus for a member of the genus Adenomera. We found that, morphologically, the buccal cavity of A. diptyx is more similar to that of the species of the Leptodactylus fuscus group than to that of A. marmorata, the only species of Adenomera whose buccal cavity is known. Adenomera diptyx shares with the species of the L. fuscus group a semicircular crest in the prenarial region, two pairs of infralabial papillae, four lingual papillae, and few papillae on the roof and the floor of the cavity. The chondrocranial morphology of A. diptyx exhibits all the characters that characterise all members of the genus Leptodactylus and several characters that are shared with the L. fuscus group: wide suprarostrals with U-shaped corpora in frontal view, long and narrow cornua, long and finger-like processi anterolaterali on the otic capsules, a posterior curvature of the palaquadrate at the level of the point of attachment of the processus ascendens of the orbital cartilage, a processus ascendens that is almost perpendicular to the main axis of the body, a connection between the processus ascendens and the orbital cartilage just posterior to the oculomotor foramen, and a processus branchialis that is open between ceratobranchials II and III. Considering that the phylogenetic relationships between Adenomera and Leptodactylus are still discussed and that information on the larval morphology of Adenomera species is scarce, new studies are necessary for a more exhaustive analysis, including further data about the internal larval morphology of Adenomera species.
Key words. Underground chamber, foam nest, tadpole, chondrocranium, oral cavity.