Osteocephalus oophagus

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 62

Osteocephalus oophagus

External morphology. Description based on three tadpoles at Stages 33 and 37 (LCS 525). Total length 26.1 and 27.3 mm (Stage 33) and 31.2 mm (Stage 37). Body ovoid in dorsal view and globular in lateral view ( Fig. 34A, B ). Snout truncate in dorsal view and rounded in lateral view. Eyes small, dorsally positioned and laterally directed. Nostrils small, circular, dorsolaterally positioned, near to eyes, with opening anterolaterally directed, without a projection on the marginal rim. Oral disc ( Fig. 34C ) anteroventral, ventrally emarginate; marginal papillae conical, uniseriate on anterior labium and irregularly biseriate on posterior labium, with a dorsal gap. Submarginal papillae present laterally. LTRF 2(2)/3; A1 and A2 of the same length; P1 and P2 similar in length; P3 shorter than others. Jaw sheaths moderately wide, without serrations; anterior jaw sheath arch-shaped, posterior jaw sheath V-shaped. Spiracle single, lateroventral, cylindrical, 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 shallow and convex, originating at the tail-body junction; ventral fin shallow, convex. Tail tip rounded.

Colour. In preservative dorsum light grayish brown; anterior region of venter pigmented and posterior region without pigment; caudal musculature lighter than body and fins translucent. In life body transparent olive with a band of white chromatophores between the eyes and the mouth; tail transparent (as Osteocephalus sp. ; Hero 1990).

Metamorphs. Dorsal and lateral surfaces grey except for a black canthal stripe continuing as a supratympanic stripe, posterior to eye to insertion of the arm; dorsal surfaces of upper arm and proximal half of lower arm white; an orange spot on elbow; a large white spot, capped by a smaller orange one, on heel; another orange spot on knee and in some specimens on outer edge of the metatarsus; finger- and toe-discs orange; iris bright red ( Fig. 34E ) ( Jungfer & Schiesari 1995).

Natural history. Eggs and tadpoles are found in phytotelms including ground or epiphytic bromeliads, palm leaf axils, water-filled palm bracts lying on the ground or (less frequently) tree holes up to heights of about 35 m in terra-firme forest ( Fig. 34D ) ( Jungfer & Schiesari 1995). Egg clutches are deposited in clumps of 10– 69 eggs, totaling 111 to 506 eggs ( Jungfer & Weygoldt 1999). Parents periodically return to lay unfertilized, trophic eggs to nourish the offspring in phytotelms. If the mother does not provide eggs, tadpoles fail to reach metamorphosis ( Jungfer & Weygoldt 1999). Tadpoles are found in most months of the year.

Comments. Tadpoles of O. oophagus from Central Amazonia (Plate 17) were illustrated by Hero (1990) and described by Jungfer & Schiesari (1995) and Schiesari et al. (1996). All descriptions differ from tadpoles herein characterized by a body slightly depressed in lateral view.

Figures

FIGURE 34. Tadpole of Osteocephalus oophagus (LCS 361-17) at Stage 39: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm). (D) Eggs in water-filled bromeliad leaf. (E) Dorsolateral view of metamorph.