Cranial features of dendrobatid larvae (Amphibia: Anura: Dendrobatidae)

Abstract

The larval neurocranium and visceral arches of seven dendrobatid species representing four genera are described, based on cleared-and-stained and serially sectioned specimens. A variety of characters is shared by all seven species. Larval features do not substantiate the assumption of close ranoid affinities of the Dendrobatidae. Instead dendrobatid larvae share features such as the special quadripartite cartilago suprarostralis, the lack of the larval processus oticus, the presence of three foramina acustica, and the lack of a foramen perilymphaticum accessorius with many bufonoid larvae. The first of these characters is unique to bufonids, hylids, dendrobatids, and some New World leptodactylids; the other characters also occur in pelobatids and are presumably plesiomorphic for the Neobatrachia. The free proximal ends of Ceratobranchialia II and III are an autapomorphy of the Dendrobatidae supporting the monophyly of the family. Some features of the cranium are paedomorphic: low cartilago orbitalis, lack of connection between cartilage orbitalis and otic capsule (most species), and vestigal taeniae tecti. New anatomical terms are introduced.

Chondrocranial development in larval Rana sylvatica (Anura: Ranidae): Morphometric analysis of cranial allometry and ontogenetic shape change

“…The number of studies describing tadpole chondrocranial morphology in a wide variety of groups has increased dramatically in recent years and some studies have shown extensive qualitative variation even among closely related species (Ruibal and Thomas, 1988;Haas, 1995Haas, , 1996Larson and de Sá , 1998;Wild, 1997Wild, , 1999. However, little information exists on the factors contributing to differences among species.…”

Ontogeny, phylogeny, and morphology in anuran larvae: Morphometric analysis of cranial development and evolution inRana tadpoles (Anura: Ranidae)

“…Comparative studies of chondrocranial anatomy in larval anurans have historically been largely qualitative (e.g., Haas, 1995Haas, , 2003Fabrezi and Vera, 1997;Larson and de Sá , 1998;Haas and Richards, 1998;Maglia et al, 2001;Pú gener et al, 2003), and while such studies are extremely valuable, it is possible that more subtle shape variation may be overlooked. For example, chondrocranial anatomy in Rana larvae is overall conserved, with very little discrete variation apparent (Larson, in prep).…”

“…The larval anuran chondrocranium is a complex structure that has been shown to vary considerably in morphology, even among closely related species (Haas, 1995;Wild, 1997Wild, , 1999Haas and Richards, 1998;Larson and de Sá , 1998), and recent research suggests that there may be considerable phylogenetic signal in chondrocranial datasets (Haas, 1996(Haas, , 2003Larson and de Sá , 1998;Maglia et al, 2001;Pú gener et al, 2003). Furthermore, given that much of the chondrocranium is intimately associated with muscles involved in gill irrigation and/or feeding, the shapes of chondrocranial cartilages provide valuable ecomorphological data that can be useful in identifying adaptational trends among larval anuran ecotypes (Gradwell, 1968(Gradwell, , 1972aWassersug and Hoff, 1979;Satel and Wassersug, 1981;Haas and Richards, 1998;Larson and Reilly, 2003).…”

Supplemental Material for 'Phylogenetic systematics of dart-poison frogs and their relatives (Amphibia, Athesphatanura, Dendrobatidae). (Bulletin of the AMNH ; no. 299)'

“…Hedges and Maxson's (1993) neighbor-joining analysis of 12S mitchondrial DNA (mtDNA) sequences also placed dendrobatids among hyloids, as did Hay et al's (1995) and Ruvinsky and Maxson's (1996) neighborjoining analyses 12S and 16S mtDNA data. Haas (1995) described an additional dendrobatid synapomorphy (viz., proximal ends of Certatobranchialia II and III free, lacking synchondritic attachment). He failed to find evidence of a ranoid relationship, but discovered a number of character-states shared with hyloid taxa; however, these characters are of uncertain polarity, and no hylodine was included to rigorously test Noble's hypothesis.…”