Atelopus manauensis

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 29-31

Atelopus manauensis

External morphology. Description based on two tadpoles at Stages 34 and 37 (LCS 611, 646). Total length 11.9 mm (Stage 34) and 13.9 mm (Stage 37). Body oval in dorsal view and globular/depressed in lateral view ( Fig. 8A, B ). Snout rounded in dorsal view and truncate in lateral view. Eyes small, dorsally positioned and laterally directed. Nostrils small, oval, dorsally positioned closer to eyes than to snout, anterolaterally directed, without projection on the marginal rim. Oral disc ( Fig. 8C, D ) ventrally positioned and directed, almost as wide as maximum body width, non-emarginate, marginal papillae conical with flat apexes, uniseriate, continuous on anterior labium and with a wide ventral gap representing 80% of posterior labium. Submarginal papillae absent. LTRF 2/3; A1 and A2 of the same length; P1, P2 and P3 of the same length. Jaw sheats not serrated; anterior jaw sheath narrow, archshaped, posterior jaw sheath moderately wide, U-shaped. The oral disc is followed by a large and very distinctive abdominal disc, rectangular-shaped, that occupies about 1/2 to 2/3 of the venter ( Fig. 8C ). Spiracle single, sinistral, conical, short and wide, posterodorsally directed, opening in the medial third of the body, with the centripetal wall not fused to the body wall and longer than the external wall. Vent tube medial, fused to the ventral fin, with a medial opening. Caudal musculature of moderate width; in lateral view, tapering abruptly and not reaching the rounded tip of tail. Dorsal fin of moderate height, convex and originating on the anterior third of the tail; ventral fin of moderate height and parallel to the ventral margin of caudal musculature. Tail tip rounded.

Colour. In preservative, body and caudal musculature brown, with dark brown large spots on dorsum, flanks and caudal musculature; fins translucent. In life, tadpole grayish brown with creamy white large spots; dorsum coppery brown; tail fins translucent.

Natural history. Eggs not observed in Central Amazonia. Eggs of related A. spumarius from Ecuador are moderately large, unpigmented, and laid in water in small jelly strings ( Duellman & Lynch 1969). Tadpoles in Central Amazonia are found in fast-flowing terra-firme forest streams, 1.5 to 4 m wide and up to 1 m deep, with a substratum consisting of sand, gravel, stones and leaf-litter. Tadpoles are benthic and adhere to the substratum by means of the abdominal disc.

Comments. Tadpoles from Central Amazonia were described as Atelopus pulcher by Gascon (1989a). They differ from those herein characterized by presenting eyes anteriorly directed, spiracle posteriorly directed (according to Fig. 1 , pg. 236), caudal musculature extending until the tail tip, and abdominal disc semicircular in shape.

Genus Rhinella . Tadpoles of genus Rhinella found in Central Amazonia share the following combination of morphological characteristics: body oval in dorsal view and depressed in lateral view; body length equals one half of the total length; tail tip rounded; oral disc anteroventrally positioned and directed, emarginate, with one row of marginal papillae except for very wide dorsal and ventral gaps; LTRF 2(2)/3.

Figures

FIGURE 1. Larval amphibian habitat in Central Amazonia. (A) isolated forest pond, (B) streamside pond, (C) forest floor, (D) bromeliad, (E) treehole (with male Trachycephalus cunauaru), (F) stream, (G) river (blackwater), (H) várzea floodplain lake with floating meadows, and (I) igapó floodplain lake. Pictures by Marcelo Gordo (A, B, D, E, F, G, H) and LS (C, I).

FIGURE 8. Tadpole of Atelopus manauensis (LCS 611) at Stage 37: (A) lateral view, (B) dorsal view, (C) ventral view (scale = 10 mm), and (D) oral disc (scale = 1 mm).