Dendropsophus minutus (Peters, 1872)

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 55

Dendropsophus minutus

External morphology. Description based on four tadpoles between Stages 32 and 38 (LCS 583/1, 585). Total length 31.6 mm (Stage 38). Body ovoid in dorsal view and triangular in lateral view ( Fig. 28A, B ). Snout rounded in dorsal view and sloped in lateral view. Eyes medium-sized, positioned and directed laterally. Nostrils small, oval, laterally positioned near to snout, anterolaterally directed, without a projection on the marginal rim. Oral disc ( Fig. 28C ) anteroventral, non-emarginate; marginal papillae conical, uniseriate ventrally and biseriate laterally, with a dorsal gap. Submarginal papillae absent. LTRF 1/2; P2 slightly longer than P1. Jaw sheaths moderately wide, both finely serrated; anterior jaw sheath M-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, conical, short and wide, posteriorly 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 dextral, fused to the ventral fin, with a dextral opening. Caudal musculature of moderate width. Dorsal fin of moderate height, convex, originating on the posterior third of the body; ventral fin of moderate height, convex. Tail with flagellum.

Colour. In preservative dorsum and caudal musculature whitish with small gray flecks; venter whitish, opaque; fins translucent. In life body transparent with a silver venter tail transparent (Hero 1990).

Variation. LTRF 0/1 or 1/2 at Stages 27 and 28.

Metamorphs: Metamorphs coppery grey ( Fig. 28D ).

Natural history: Gravid females contain on average 212 ovarian eggs (Ĥdl 1990). Tadpoles are found in isolated temporary ponds of forest, forest edge and deforested land (Hero 1990). Tadpoles are found in the late rainy season. Tadpoles are nektonic.

Comments. As expected, considering the wide geographical distribution of D. minutus , some morphological characters vary among populations, especially the number of marginal papillae rows and LTRF. Marginal papillae rows vary from uniseriate ( Trinidad, Kenny 1969; Venezuela, Duellman 1997; northeastern Brazil, Dubeux et al. 2020; southeastern Brazil, Pezzuti et al. 2021), biseriate ventrally (Mato Grosso do Sul, Brazil, Bokermann 1963, although Fig. 21 shows biseriate also laterally; Colombian Amazonia, Lynch & Suárez-Mayorga 2011), biseriate ventrally and laterally ( Ecuador, Duellman 1978; southeastern S„o Paulo, Brazil, Heyer et al. 1990), uniseriate anteriorly, uni- or biseriate laterally and bi- or triseriate ventrally (lowlands of Bolívia, Schulze et al. 2015), and uniseriare ventrally and biseriate laterally (northwestern S„o Paulo, Brazil, Rossa-Feres & Nomura 2006), as those described here from Central Amazonia, which differ from those with uniseriated marginal papillae illustrated in Hero (1990) for the same region. The labial tooth row formula varies from 0/1 ( Bokermann 1963; Duellman 1997) to 0/2 ( Duellman 1978), 0/0-2 ( Schulze et al. 2015) and 1/2 ( Kenny 1969: Cei 1980; Heyer et al. 1990; Dubeaux et al. 2020, Pezzuti et al. 2021; this study). It is important to note that LTRF in the same population can vary from 0/0 to 0/1 and 1/2 ( Vizotto 1967; Rossa-Feres & Nomura 2006). Consistent with such variation, Duellman (1997) suggested that D. minutus could be a species-complex.

Figures

FIGURE 21. Tadpole of Boana punctata (LCS 650) at Stage 39: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).

FIGURE 28. Tadpole of Dendropsophus minutus (LCS 585) at Stage 38: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm). (D) Dorsolateral view of newly metamorphosed froglet.