Vitreorana ritae

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 34-36

Vitreorana ritae

External morphology. Description is based on six tadpoles at Stage 25 (INPA-H 1592). Total length 13.2 ± 0.3 mm (N = 6). Body elongate oval in dorsal view and very depressed in lateral view ( Fig. 12A, B ). Snout truncate in both dorsal and lateral views. Eyes extremely small, dorsally positioned and dorsolaterally directed and without pigmentation. Nostrils small, rounded, dorsolaterally positioned closer to snout than to eyes, with opening dorsolaterally directed, without a projection on the marginal rim. Oral disc ( Fig. 12C ) ventral, non-emarginate; marginal papillae triangular, uniseriate, positioned lateroposteriorly. Submarginal papillae absent. LTRF 0/2; P1 slightly longer than P2. Jaw sheaths wide and strongly serrated; anterior jaw sheath arch-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, conical, very short and wide, posteriorly directed, opening in the posterior third of the body, with the centripetal wall fused to the body wall, with a free distal edge and of the same length as the external wall. Vent tube medial, fused to the ventral fin, with a medial opening. Caudal musculature of moderate width; in lateral view gradually tapering to a pointed tip. Dorsal fin low, slightly convex, originating at the tail-body junction; ventral fin low and parallel to the ventral margin of the caudal musculature. Tail tip rounded.

Colour. In preservative, dorsum and caudal musculature from pinkish to light brown with dark melanophores, venter whitish, tail fins translucent. In life, because of the absence of pigment, tadpoles present dorsum reddish brown, since the underlying blood vessels are unmasked; venter whitish, tail muscle reddish and tail fins transparent ( Menin et al. 2009a).

Variation. LTRF 0/0 or 0/1 at Stage 25.

Natural history. Eggs are laid on the upper or underside surfaces of leaves overhanging (from 0.5 to 1 m above water surface) streams in terra-firme forests ( Menin et al. 2009a; Lima et al. 2012). Clutches contain from 12 to 18 pale green eggs distributed as a single layer (mean 16 eggs; N = 4; Fig. 12D, E ). Upon hatching tadpoles fall in the water and assume their typical fossorial habits: tadpoles live burrowed in leaf mats and gravel, using its long and strong muscular tail with shallow fins especially for digging ( Menin et al. 2009a). Tadpoles at Stage 25 hatched in the laboratory still had a relatively undifferentiated gut, a cream-colored abdomen and a very small opening of the vent tube which may be suggestive of reliance on endotrophy at this stage. Larvae are found in all months of the year. Eggs are preyed upon by phorid fly larvae (Ĥdl 1993). In experiments tadpoles were found to be preyed upon by fish ( Hero 1991).

Comments. Tadpoles from Central Amazonia were illustrated by Hero (1990; Plate 5) and described by Menin et al. (2009) as Vitreorana oyampiensis , and they differ from those herein characterized by presenting body elongate rectangular in dorsal view and spiracle posteriorly directed.

CERATOPHRYIDAE

Genus Ceratophrys . Only one species of Ceratophrys is found in Central Amazonia.

Figures

FIGURE 12. Tadpole of Vitreorana ritae (INPA-H 1592) at Stage 25: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm). (D) Eggs and (E) embryos.