Full length paper

Descripción y comparación del condrocráneo en larvas de Hyla raniceps (Cope, 1862), Scinax granulatus (Peters, 1871) y Scinax squalirostris (A. Lutz, 1925) (Anura: Hylidae)

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Cuadernos de Herpetología 17 (1-2): 33-49, 2003 alcalde@ilpla.edu.ar

Abstract

The larval chondrocranium of 3 species of neotropical hylids, Hyla raniceps, Scinax granulatus and S. squalirostris is described, which present pond type, type IV, with exotrophic development, nektonic (Scinax spp.) or benthic (H. raniceps) tadpoles. The obtained data were compared with known information about Hyla andina, H. arborea, H. cinerea, H. geographica, H. lanciformis, H. microcephala, H. nana, H. pulchella, H. rosenbergi, Scinax acuminatus, S. fuscovarius, S. nasicus and S. ruber. The species of Scinax are differentiated from those of Hyla independently of the ecological type of their tadpoles by the presence of a process lateral to the ceratohyal?s condilus articularis (which is absent in Hyla spp.). The question about if this process is a sinapomorphy either for Scinax or the species that compound the rubra clade, could not be dilucidated. Seventeen characters vary among species independently of the environment and the diet of tadpoles: five of them are from the neurocranium, five from the mandibular arch and seven from the hiobranquium. The grade of development of the anterolateral process of the ceratohyale shows association with the feeding mechanism of tadpoles. Three characters support species groups on genus Hyla. Hyla lanciformis and H. raniceps (albopuntacta group) have the commissura quadrato-cranialis anterior a half of wide compared with the wide of the processus muscularis quadrati at its base, and a V-shaped pars reuniens. Hyla geographica (geographica group) presents a square-shaped pars reuniens. In Hyla nana (microcephala group), the sinus posterior hypobranchialis and the processus quadrato-ethmoidale are missing. The rostrata group from genus Scinax appears supported by the presence of a sindesmotic connection between corpus and ala of the cartilago suprarostrale. The existence of differences in the chondrocranial structures related whit diet in tadpoles that present the same microphagous feeding mechanism, indicates that this type of diet occurs by a series of structures and do not with a single particular morphology.

Key words:

Hyla; Scinax; larvas; condrocráneo

Received: Mar. 04, 2003 ▪ Accepted: Sep. 05, 2003

Associate Editor: M. Fabrezi
Alcalde, L. & Rosset, S.D. 2003. Descripción y comparación del condrocráneo en larvas de Hyla raniceps (Cope, 1862), Scinax granulatus (Peters, 1871) y Scinax squalirostris (A. Lutz, 1925) (Anura: Hylidae). Cuadernos de Herpetología 17: 33-49.