Trachycephalus coriaceus (Peters, 1867)

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 79-81

Trachycephalus coriaceus

External morphology. Description based on two tadpoles at Stages 36 and 37 (LCS 630, 645). Total length 35.9 mm (Stage 36) and 39.9 mm (Stage 37). Body elongate oval in dorsal view and triangular in lateral view ( Fig. 49A, B ). Snout truncate in dorsal and lateral views. Eyes medium-sized, positioned and directed laterally. Nostrils small, circular, laterally positioned near to snout, with opening anterolaterally directed, without a projection on the marginal rim. Oral disc ( Fig. 49C ) anteroventral, ventrolaterally emarginate; marginal papillae conical, biseriate, with a dorsal gap. Submarginal papillae present laterally. LTRF 4(1,2,4)/6(1); Ae1 and Ae2 shorter and fragmented, A1 continuous and A2 interrupted, both longer than others; P1 shorter than all other rows. Anterior jaw sheath wider than posterior jaw sheath, both finely serrated; anterior jaw sheath arch-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, conical, short and wide, posterodorsally directed, opening in the medial third of the body, with the centripetal wall 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 gradually tapering to a pointed tip. Dorsal fin of moderate height, originating on the posterior third of the body, convex; ventral fin shallow and convex. Tail tip pointed. Lateral lines visible.

Colour. In preservative body and caudal musculature grayish brown with wide black spots; venter translucent; fins translucent with scattered melanophores. In life body pale to dark grayish brown commonly with wide black spots; caudal musculature pale to dark brown, commonly with black spots, with one dorsolateral and one ventrolateral white stripe per side; fins transparent with or without melanophores; venter silvery white; iris golden to cooper ( Fig. 49D–E ) ( Schiesari & Moreira 1996).

Metamorphs. Dorsum bronze with black spots; venter white; eyes red; loreal area cream; black canthal stripe continues laterally until angles of jaw; limbs greenish brown, except for cream dorsum of arms and heels; fingers and toes translucent orange; bones green ( Fig. 49F ) ( Schiesari & Moreira 1996).

Natural history. One gravid female of T. coriaceus from Ecuador contained 1,430 ovarian eggs ( Crump 1974). Clutches from Peru contain from 1,150 to 1,350 eggs ( Duellman 2005). Pigmented eggs are deposited in a circular monolayer film on the water surface. The only reproductive event recorded in Central Amazonia occurred immediately after a heavy storm formed a large (400 m 2, 1 m deep), temporary, isolated forest pond in terra-firme forest ( Schiesari & Moreira 1996).

Comments. Tadpoles from the same lot described by Schiesari & Moreira (1996) differ from those herein characterized by presenting snout rounded in lateral view, spiracle lateroventral, oral disc non-emarginate, and marginal papillae row uniseriate to biseriate. Tadpoles of T. coriaceus from Peru described by Duellman (2005) differ from those herein characterized by presenting snout rounded in dorsal and lateral view, vent tube dextral, submarginal papillae absent, posterior jaw sheath V-shaped, LTRF 4(1,3,4)/7(1) and posterior tooth rows shorter than the anterior ones, being P6 and P7 the shortest and poorly developed.

Figures

FIGURE 49. Tadpole of Trachycephalus coriaceus (LCS 631) at Stage 35: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm). (D) lateral and (E) dorsolateral view of live tadpole, and (E) newly metamorphosed froglet. In (E) note conspicuous lateral line system.