Hylodes uai Nascimento, Pombal & Haddad, 2001

Weber, Luiz Norberto & Caramaschi, Ulisses, 2013, A survey of the internal oral morphology in larvae of the genus Hylodes Fitzinger, 1826 (Amphibia, Anura, Hylodidae), Zootaxa 3635 (5), pp. 557-568 : 565-567

Hylodes uai Nascimento, Pombal & Haddad, 2001

Material: one specimen (stage 30) and two specimens (stage 36).

Ventral aspect ( Fig. 8 A): Buccal floor triangular, wider than long; one or two pairs of infralabial papillae present, being almost not discernible the lowest pair; the outer pair has a complex structure and is longer than wide, with five to eight finger-shaped projections of irregular margin that touch each other; the posterior pair approximately equivalent to half the length of the lingual papilla, and it is small, with irregular truncate apex surface; two filiform lingual papillae present, placed side by side, tapered; lingual papillae closer to the first papilla of the buccal floor arena than to the infralabial papilla; there are about 20–30 papillae on each side, enclosing the buccal floor arena and extending from the region near the tongue rudiments to near the ventral velum; papillae directed to the arena center, finger-shaped and curved; arena papillae arranged similar to a U; there are about 15–20 small conical papillae on the base of arena; the bigger papilla of the floor arena is bifurcate, located in the middle portion of the arena; some arena papillae show irregular margin; about two to three prepocket papillae, small to medium-sized, similar to those from the buccal floor arena; large number of pustules present on the arena surface, evenly distributed; ventral velum with accentuated median notch, undulated margin and about six to eight fingershaped projections, well developed, above the glottis.

Dorsal aspect ( Fig. 8 B): Buccal roof triangular, somewhat shaped as the floor; prenarial arena with low crest and shaped as a reversed V, low distinctive in some specimens; reniform choanae, separated and oriented at an angle of 45° in relation to the transverse plane; distance between choanae slightly lower than the width of the median-ridge; diminute and conical pre-choanal papillae, about three or four per choana; postnarial arena with six to ten papillae, arranged on each side in a separate row, papillae with varied sizes and finger-shaped; largest papillae postero-located, finger-shaped, with sharp apex, irregular antero-margin, and directed to the center; cluster of papillae in postnarial arena forming an inverted V; presence of a small papilla ahead of the median ridge, not covered by it; complex lateral-ridge papillae, hand-shaped with five to six ramifications of anterior margin finely serrate and directed to the center, the first ramification less developed than the others; the median ridge triangularshaped with irregular margin; buccal roof arena bordered by 11-12 papillae on each side, finger-shaped, tapered and with anterior margin aliasing, directed up and to the arena center; absence of bifurcate papilla in the arena; presence of about ten small conical papillae on the base arena; arena papillae forming an approximate U design; pustules are present and evenly distributed; distinct row with about five to thirteen lateral papillae on the roof arena; not distinct glandular area; dorsal velum medially interrupted, having about seven to nine projections of medium to long size.

Discussion

Hylodes nasus (Wassersug and Heyer 1988; treated as Hylodes cf. asperus in error according to Costa et al. 2010a), H. asper (Costa et al. 2010a); H. charadranaetes (Costa et al. 2010b), H. ornatus (Costa et al. 2012) and H. magalhaesi (Gomes et al. 2012) have the oral internal morphology previously described. Our study corroborates the comparison proposed by Costa et al. (2012) within these species. The former of the structures and the overall aspect is very similar within, differing in the quantity of some papillae and structures, as projections or pustules. We also discriminate two patterns in buccal floor and buccal roof arena, about the arrangement of the papillae: in V or U and in two almost parallel lines.

Comparison among Hylodes species. Ventral aspect: To distinguish the lowest pair of infralabial papillae is critical. In some ( H. asper , H. charadranaetes , H. dactylocinus , H. heyeri , H. magalhaesi , H. meridionalis , and H. nasus ), are discernible but in others the diminute size or the proximity with the larger pair of infralabial papillae difficult their characterization ( H. ornatus , H. phyllodes , H. sazimai , and H. uai ). This condition is also present intraspecifically ( H. phyllodes , H. sazimai , and H. uai ). The largest infralabial pair is discernible in all species and the number of finger-liked projections is variable (four to eight), being four projections the most common pattern. The number (two) and the shape (filiform) of lingual papillae is constant in all species (except in one ondividual at stage 26 of H. phyllodes occurred just one lingual papilla). The arrangement of the buccal floor arena papillae and pustules is similar a U/V or the arena papillae are arranged in two, almost parallel lines directed to the center of buccal arena. The number of the finger-shaped papillae of the buccal floor arena is variable among species, and the presence of a large bifurcate papillae in floor arena occurs in all species. The presence of conical little papillae close to the posterior surface of the buccal floor arena is common in most species, not so evident in H. asper , H. dactylocinus , and H. heyeri . It is also common the presence of pustules in the surface of the arena, more posterior concentrated. The presence of projections above the glottis is common in all species of the genus, but the size is different between them: projections with little or small size ( H. dactylocinus and H. sazimai ); projections with medium size ( H. asper , H. aff. lateristrigatus, H. meridionalis , H. nasus , and H. ornatus ); and projections developed/well developed ( H. charadranaetes , H. heyeri , H. magalhaesi , H. phyllodes , and H. uai ).

Dorsal aspect: Prenarial arena with low crest and shaped as a reversed V, but poorly distinctive in some specimens, is common. Pre-choanal papillae, when present, are difficult to observe. A cluster of papillae in postnarial arena forming an inverted V is present in all species. The presence of complex lateral-ridge papillae, hand-shaped with four to eight ramifications, occurs in all species. The median ridge triangular-shaped is the most common ( H. asper , H. charadranaetes , H. dactylocinus , H. aff. lateristrigatus, H. meridionalis , H. phyllodes , and H. uai ). The number and position of the buccal roof papillae and pustules are variable among the species. Two patterns are discernible: in U/V ( H. asper , H. dactylocinus , H. heyeri , H. aff. lateristrigatus, H. meridionalis , H. nasus , H. sazimai , and H. uai ) and in two almost parallel lines ( H. charadranaetes , H. magalhaesi , H. ornatus , and H. phyllodes ). The number of pustules in the buccal roof arena is variable among species, but the most species have a large number of them ( H. charadranaetes , H. heyeri , H. aff. lateristrigatus, H. magalhaesi , H. ornatus , H. phyllodes , H. sazimai , and H. uai ), some species has an intermediary number ( H. meridionalis and H. nasus ) or just some little pustules are present ( H. asper and H. dactylocinus ). The glandular zone is not so discernible in H. asper , H. dactylocinus H. heyeri , H. meridionalis , and H. nasus .

Figures

FIGURE 8 (A) Floor and (B) roof of the buccal surface in a Hylodes uai tadpoles at stage 36. Scale = 1 mm.