Leptodactylus pentadactylus (Laurenti, 1768)

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 91-92

Leptodactylus pentadactylus

External morphology. Description based on one tadpole at Stage 36 (INPA-H 10321). Total length 73.4 mm. Body ovoid in dorsal view and globular/depressed in lateral view ( Fig. 58A, B ). Snout rounded in dorsal view and truncate in lateral view. Eyes small, dorsally positioned and dorsolaterally directed. Nostrils small, circular, dorsolaterally positioned in an intermediate distance between the eyes and the snout, with opening anterolaterally direct- ed, without a projection on the marginal rim. Oral disc ( Fig. 58C ) anteroventral, non-emarginate; marginal papillae blunt, uniseriate, with a dorsal gap. Submarginal papillae absent. LTRF 1/2(1); P2 shorter than P1. Jaw sheaths wide, finely serrated; anterior jaw sheath arch-shaped, posterior jaw sheath V-shaped. Spiracle single, 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 medial opening. As typical to tadpoles of L. pentadactylus group, tail long, corresponding to about 68% of total length; caudal musculature of moderate width; in lateral view gradually tapering to a pointed tip. Dorsal fin shallow, originating at the tail, convex; ventral fin shallow with margin parallel to the ventral margin of caudal musculature. Tail tip rounded.

Colour. In preservative dorsum grayish brown; venter cream; caudal musculature cream; fins translucent pale cream. In life body and caudal musculature dark grey or black; venter silver or ark silver; fins translucent ( Menin et al. 2010).

Metamorphs. Dorsal region reddish brown with well-defined, narrow transverse bands between the eyes and on the dorsum; each side has one dorsolateral stripe from eye to the middle of the urostyle and a thicker stripe beginning at the mouth, passing through nostrils and eyes, and making a downward curve and ending above the tympanum; mouth traversed by transversal bars through its entire width; venter with light patches on a dark gray background; limbs with transversal thick stripes.

Natural history. Eggs were not observed. Foam nests are deposited in burrows in clayish soil, within an excavated basin at the bottom of the burrow; the observed burrows had no water and were distant from water bodies ( Hero & Galatti 1990; Menin et al. 2010). Eggs were observed in the gut of one tadpole at Stage 29 ( Menin et al. 2010). All tadpoles examined had the abdomen heavily irrigated by wide, well ramified blood vessels visible from dorsal and lateral views. This morphological feature plus completely terrestrial development might argue that tadpole development is sustained by yolk, but the very large size attained by larvae and the observation of eggs in tadpole guts in the few nests found suggest that oral food consumption is obligate. In experiment L. pendadactylus was found to be a voracious amphibian egg-eater ( Magnusson & Hero 1991).

Comments. Tadpoles from Ecuador characterized by Duellman (1978) differ from those herein characterized by presenting snout rounded in lateral view, spiracle opening at midline of body, LTRF 2(2)/3, and tail tip pointed. Tadpoles from Central Amazonia were illustrated by Hero (1990) and described by Menin et al. (2010). Tadpoles from Peru were described by Duellman (2005). Tadpoles illustrated by Hero (1990) differ from those herein characterized by presenting dorsal fin parallel to the longitudinal axis of the tail. Tadpoles described by Menin et al. (2010) differ from those herein characterized by presenting snout rounded in dorsal and lateral views, and spiracle posteriorly directed. Tadpoles described by Duellman (2005) differ from those herein characterized by presenting snout rounded in dorsal and lateral views, vent tube dextral, and LRTF 2/3 with all tooth rows of same length ( Duellman 2005).

Figures

FIGURE 58. Tadpole of Leptodactylus pentadactylus (MNRJ 7843) at Stage 38: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).