Sphaenorhynchus carneus

Sphaenorhynchus carneus

External morphology. Description based on one tadpole at Stage 37 (LCS 599). Total length 30.1 mm. Body elongate oval in dorsal view and globular/depressed in lateral view (Fig. 46A, B). Snout rounded in dorsal view and truncate in lateral view. Eyes small, positioned and directed laterally. Nostrils small, oval, laterally positioned, near to eyes, with opening anterolaterally directed, with a small projection on the marginal rim. Oral disc (Fig. 46C) anteroventral, non-emarginate; marginal papillae triangular, uniseriate, without any interruption. Submarginal papillae absent. LTRF 1/2(1); P2 shorter than P1. Jaw sheaths narrow, finely serrated; anterior jaw sheath arch-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, cylindrical, long and narrow, 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 shallow, originating at the body-tail junction, convex; ventral fin shallow and convex. Tail tip rounded.

Colour. In preservative body and caudal musculature light olive brown with irregular dark brown marks; fins translucent with dark brown irregular marks; venter with two dark brown longitudinal stripes, one on each side of the gular region. Tadpoles of S. carneus from Colombia have dorsum green with a canthal line red; caudal musculature with a red line; fins green translucent; venter with two evident purple longitudinal stripes, one on each side of the gular region (Suárez-Mayorga & Lynch 2001).

Variation. LTRF 0/0 in Stages 25 and 26, 0/2(1) or 1/2(1) between Stages 26 and 29.

Metamorphs. Metamorphs yellowish green with a grey mark between the eyes (Fig. 46D, E).

Natural history. Eggs were not observed in Central Amazonia. Gravid females contain on average 152 ovarian eggs (Ĥdl 1990). Tadpoles are found in floating meadows in várzea floodplain lakes.

Comments. These tadpoles were illustrated by Lynch & Suárez-Mayorga (2011) from the eastern lowlands of Colombia and they differ from those herein characterized by presenting LTRF 1/3(1), dorsal gap in the marginal papillae row, and tail tip pointed.