A hundred-year-old mystery-the reproductive mode and larval morphology of the enigmatic frog genus Allophryne (Amphibia; Anura; Allophrynidae).

Frogs of the Allophrynidae are an enigmatic family from South America. To date, published information is lacking regarding this group's reproductive biology and larval morphology. Here, we provide the first detailed description of the reproductive mode, developmental mode, and tadpole morphology for Allophryne ruthveni. We developed a captive breeding and rearing protocol for this species and then conducted a series of observations to describe aspects of its reproductive biology. In captivity, this species exhibits aquatic oviposition, where single eggs are laid ungrouped within a simple jelly capsule and are scattered free in the water column before sinking to develop on benthic substrates. We did not observe parental care nor any parental interactions with eggs post-fertilization. Tadpoles are characterized by an oval body, anteroventral oral disc, a labial tooth row formula of 2(2)/3, and a dextral vent tube. The buccopharyngeal cavity is marked by the presence of two pairs of infralabial papilla and four lingual papillae. Cranial morphology is characterized by the presence of the commissura quadratoorbital. This species possesses an additional slip of the m. rectus cervicis and of the m. levator arcuum branchialium III. We discuss our results in comparison with glassfrogs (Centrolenidae).

Harlequin frog tadpoles-comparative buccopharyngeal morphology in the gastromyzophorous tadpoles of the genus Atelopus (Amphibia, Anura, Bufonidae), with discussion on the phylogenetic and evolutionary implication of characters.

The Neotropical genus Atelopus is the most diverse genus of bufonids comprising 99 species. Tadpoles of these frogs are readily distinguished based on the presence of a belly sucker, used by them to stay attached to rocks in fast-flowing streams. Despite their intriguing biology, information about their anatomy is scarce and many morphological systems are unknown. We describe the buccopharyngeal cavity of five Atelopus species. The Atelopus buccopharyngeal cavity is characterized by (1) presence of a pendulum-like papillae in the prenarial arena, (2) presence of a glandular zone in the prenarial arena, (3) narial vacuities, (4) conical median ridge, (5) absence of buccal roof arena papillae, (6) absence of buccal roof pustulations, (7) single pair of infralabial papillae, (8) absence of lingual papillae, and (9) absence of pustulations in the buccal floor. We propose that characters 1, 2, and 3 are new synapomorphies for the genus. We also propose that the presence of a single pair of infralabial papillae is a synapomorphy for bufonid. Finally, we discuss the convergent evolution of gastromyzophorous and suctorial tadpoles withing anurans.

Anatomical features of the phytotelma dwelling, egg-eating, fanged tadpoles of Rhacophorus vampyrus (Anura: Rhacophoridae).

Tadpoles of the Vampire tree frog Rhacophorus vampyrus differ substantially from other rhacophorid tadpoles, by having profound modifications in external morphology. The morphological peculiarities of this species likely correlate with their arboreal microhabitat and strict oophagous diet. In this work, we examine buccal and musculoskeletal anatomy and compare them to other rhacophorid and egg-eating larvae. The shape and arrangement of cartilages of the lower jaw are unique among tadpoles, and the lack of a palatoquadrate suspensorium is only known in the distantly related macrophagous tadpoles of the dicroglossid Occidozyga baluensis. The cranial musculature is massive, and the morphology of several mandibular, hyoid, and abdominal muscles could be related to the ingestion and transit of large eggs. In the buccal cavity, conspicuous aspects are the absence of ridges and papillae, and the development of a unique glandular zone in the buccal floor. Finally, observations of the skeletal support of keratinized mouthparts allow us to present a topography-based hypothesis of homology of the conspicuous fangs of these tadpoles.

The remarkable larval anatomy of Proceratophrys minuta Napoli, Cruz, Abreu and Del-Grande, 2011 (Amphibia: Anura: Odontophrynidae).

The free living larvae of anurans (i.e., tadpoles) are a key element in the evolution and diversification of this group, and as such, their morphology is an important element to understand the phylogenetic relationships of frogs. However, the lack of data on larval morphology prevents us from fully understanding larval evolution in several lineages. The Neotropical genus Proceratophrys currently comprises 39 species, but descriptions of the internal morphology of larvae in this group are rare and restricted to few aspects of their buccopharyngeal cavity, chondrocranium, and muscles. In the present study, I describe the internal anatomy of the tadpole of P. minuta and report a new remarkable myological character state for the species. Given the rarity of this material, the description of this species' buccopharyngeal and musculo-skeletal elements is based on two tadpoles in developmental stages 30 and 31. Several new apomorphic character states are described: (a) the presence of a conical papilla in the interior of the nostril; (b) a row of five short, conical papilla preceding the tall, postnarial papilla; and (c) the m. mandibulolabialis inserting in the gular skin. This latter feature is a remarkable, newly discovered character state that had never been reported in the literature before and is probably related to a particular feeding habit of the tadpoles of this species. The function of the m. mandibulolabialis in P. minuta is unknown.

The poverty of adult morphology: Bioacoustics, genetics, and internal tadpole morphology reveal a new species of glassfrog (Anura: Centrolenidae: Ikakogi) from the Sierra Nevada de Santa Marta, Colombia.

Ikakogi is a behaviorally and morphologically intriguing genus of glassfrog. Using tadpole morphology, vocalizations, and DNA, a new species is described from the Sierra Nevada de Santa Marta (SNSM), an isolated mountain range in northern Colombia. The new taxon is the second known species of the genus Ikakogi and is morphologically identical to I. tayrona (except for some larval characters) but differs by its genetic distance (14.8% in mitochondrial encoded cytochrome b MT-CYB; ca. 371 bp) and by the dominant frequency of its advertisement call (2928-3273 Hz in contrast to 2650-2870 Hz in I. tayrona). They also differ in the number of lateral buccal floor papillae, and the position of the buccal roof arena papillae. Additionally, the new species is differentiated from all other species of Centrolenidae by the following traits: tympanum visible, vomerine teeth absent, humeral spines present in adult males, bones in life white with pale green in epiphyses, minute punctuations present on green skin dorsum, and flanks with lateral row of small, enameled dots that extend from below eye to just posterior to arm insertion. We describe the external and internal larval morphology of the new species and we redescribe the larval morphology of Ikakogi tayrona on the basis of field collected specimens representing several stages of development from early to late metamorphosis. We discuss the relevance of larval morphology for the taxonomy and systematics of Ikakogi and other centrolenid genera. Finally, we document intraspecific larval variation in meristic characters and ontogenetic changes in eye size, coloration, and labial tooth-rows formulas, and compare tadpoles of related species. Ikakogi tayrona has been proposed as the sister taxon of all other Centrolenidae; our observations and new species description offers insights about the ancestral character-states of adults, egg clutches, and larval features in this lineage of frogs.