Trachycephalus typhonius (Linnaeus, 1758)

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 82-83

Trachycephalus typhonius

External morphology. Description based on one tadpole at Stage 39 (MZUSP 64364). Total length 37.6 mm. Body elongate oval in dorsal view and triangular in lateral view ( Fig. 51A, B ). Snout rounded in dorsal and lateral views. Eyes medium-sized, positioned and directed laterally. Nostrils small, oval, dorsolaterally positioned in an intermediate distance between the eyes and the snout, with opening anterolaterally directed, without a projection on the marginal rim. Oral disc ( Fig. 51C ) anteroventral, ventrolaterally emarginate; marginal papillae conical, biseriate, with a dorsal gap. Submarginal papillae present laterally. LTRF 3(1,3)/3(1); Ae1 fragmented and A2 slightly shorter than A1; P1, P2, and P3 similar in the length. Anterior jaw sheath wider than posterior jaw sheath, both finely serrated; anterior jaw sheath arch-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, lateroventral, 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 dextral opening. Caudal musculature of moderate width; in lateral view gradually tapering to a pointed tip. Dorsal fin high, originating on the posterior third of the body, convex; ventral fin high and convex. Tail tip pointed. Lateral lines visible.

Colour. Tadpoles of T. typhonius (as Phrynohyas venulosa ) from Peru have dorsum pale brown with darker brown spots; venter bluish gray; dorsal edge and midlateral part of the caudal musculature dark brown; two cream stripes present on the tail; fins translucent ( Duellman 2005). In life not observed, but tadpoles of T. typhonius (as Phrynohyas venulosa ) from Peru have body brown dorsally, with a few scattered dark brown flecks; venter dull white; caudal musculature cream with brown stripes, but distal part of the tail bluish gray; iris reddish bronze ( Duellman 1978, 2005).

Variation. LTRF varied from 2/3 at Stage 25; 3/4 at Stages 30, 31, and 38; 3/5 at Stages 34, 35, 39, and 40, and 4/5 at Stage 36 (presence and position of gaps not indicated) (Schiesari et al. 1996).

Natural history. Eggs were not observed in Central Amazonia. Gravid females of T. typhonius from Peru contain from 1,230 to 1,820 pigmented eggs ( Duellman 2005). Eggs are deposited as a surface film on the surface of the water in temporary ponds ( Duellman 1978, 2005). In Central Amazonia T. typhonius occurs in várzea floodplains and deforested land. Eggs and tadpoles were found in several small pools formed in disturbed areas in Eastern Amazonia, Pará, Brazil ( Caldwell & Araújo 2005). Ponds ranged from very small to 4 m in diameter and lacked vegetation, and tadpoles aggregated in two large, loosely organized schools ( Caldwell & Araújo 2005).

Comments. Tadpoles of T. typhonius were described by Kenny (1969) as Phrynohyas zonata from Trinidad; Duellman (1970) as Phrynohyas venulosa from Panamá and México, and Duellman (1978, 2005) from Ecuador and Peru, respectively; Schiesari et al. (1996) as Phrynohyas venulosa from northern Amazonia, Roraima, Brazil; Rossa-Feres & Nomura (2006) as Trachycephalus venulosus from Southeastern Brazil, Lynch (2006) from Colombia, and by Schulze et al. (2015) from lowland Bolivia. Tadpoles differ from those herein characterized by presenting snout sloped in lateral view, LRTF 4(1,2,4)/6(1,6), and posterior jaw sheath V-shaped ( Rossa-Feres & Nomura 2006; Duellman 1970); snout rounded in lateral view, vent tube dextral, posterior jaw sheath V-shaped, LTRF 3(1,3)/6(1,6), being the inner anterior and the outer posterior rows present only laterally (although Fig. 13.14C shows a short ventral P6; Duellman 2005; Lynch 2006); vent tube sinistral ( Duellman 1978) and LRTF 3(1)/6 with a weak P6 row; vent tube dextral and absence of submarginal papillae ( Duellman 2005); uniseriate row of marginal papillae and LRTF 3(1,3)/5(1,2,3) ( Fig. 26 ; Kenny 1969); oral disc slightly emarginate posteriorly, marginal papillae irregularly uniseriate to biseriate, posterior jaw-sheath V-shaped ( Schulze et al. 2015). Moreover, Schulze et al. (2015) considered the tail as possessing a broad flagellum and commented that LRTF is very variable with regard to tooth rows and gaps, 3-4(1,3,4)[2]/4-6(1,6)[3,5], explaining the difference in these characters in the several descriptions. This variation encompasses the difference in LRTF considered by Pyburn (1967) to differentiate P. spilomma from T. typhonius (as P. venulosa ).

LEPTODACTYLIDAE . Tadpoles of the leptodactylid species occurring in Central Amazonia belong to three genera with free-swimming ( Leptodactylus and Lithodytes ) or terrestrial endotrophic tadpoles ( Adenomera ). The morphology of these genera is very distinctive.

Genus Adenomera . Tadpoles of genus Adenomera found in the Central Amazonia share the following combination of morphological characteristics: small size; body oval elongate in dorsal view and globular/depressed in lateral view; spiracle absent; vent tube medial; oral disc anteroventral; marginal papillae uniseriate with dorsal and ventral gaps; LTRF 0/0.

Figures

FIGURE 13. Tadpole of Ceratophrys cornuta (MNRJ s/n) at Stage 38: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).

FIGURE 26. Tadpole of Dendropsophus leucophyllatus (MZUSP 64335) at Stage 39: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).

FIGURE 51. Tadpole of Trachycephalus typhonius (MZUSP 64364) at Stage 39: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).