Rhinella marina (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 : 31-32

Rhinella marina

External morphology. Description based on nine tadpoles at Stages 36 and 37 (LCS 649). Total length 20.6 ± 0.6 mm (N = 9). Body oval in dorsal view and globular/depressed in lateral view ( Fig. 9A, B ). Snout rounded in both dorsal and lateral views. Eyes medium-sized, dorsally positioned and dorsolaterally directed. Nostrils medium-sized, oval, dorsally positioned closer to eyes than to snout, with opening anterodorsally directed, without a projection on the marginal rim. Oral disc ( Fig. 9C ) anteroventral, laterally emarginate; marginal papillae elongate, uniseriate, with wide dorsal and ventral gaps. Submarginal papillae forming an irregular row lateroanteriorly and lateroposteriorly. LTRF 2(2)/3; A1 and A2 of the same length; P1 slightly longer than P2; P3 shorter than P2. Jaw sheaths moderately wide, finely serrated; anterior jaw sheath arch-shaped, posterior jaw sheath U-shaped. Spiracle single, sinistral, slightly below the body midline, 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. Caudal musculature of moderate width; in lateral view gradually tapering to a pointed tip. Dorsal fin of moderate height, convex, originating at the tail-body junction; ventral fin of moderate height and parallel to the ventral margin of caudal musculature. Tail tip rounded.

Colour. In preservative, dorsum, flanks of body and dorsal half to 2/3 of the caudal musculature dark brown to black; ventral half to 1/3 of the caudal musculature unpigmented; chest dark grey, venter black, tail fins transparent. In life, body black, dorsal half to 2/3 of the caudal musculature black, venter black, ventral half to 1/3 of caudal musculature unpigmented, tail fins tansparent.

Natural history. Pigmented eggs are deposited in shallow water as two gelatinous strings with 4,000 to 10,000 eggs ( Lima et al. 2012). Tadpoles are found in the dry season in temporary and permanent ponds and lakes in terrafirme forest edge, deforested land and várzea and igapó floodplains. Tadpoles are unpalatable to fish and form ameboid, loosely aggregated schools ( Wassersug 1973). The black color is presumably aposematic. Tadpoles exhibit necrophagy. Tadpoles are preyed upon by the snake Helicops angulatus ( Kaefer & Montanarin 2011) .

Comments. Tadpoles of R. marina were previously described by Savage (1960) from Panamá, Kenny (1969) from Trinidad and Tobago, Duellman (1978) from Ecuador, Hero (1990) from Central Amazonia, Brazil, Rada de Martinez (1990) from Venezuela, Ford & Scott (1996) from Mexico, Duelman (2005) from Peru, and Lynch (2006) from Colombia. As expected for such wide geographic range, several chacteristics were found to vary between the tadpoles herein characterized, and those described from other locations. These are dorsal fin originating on the tail, nostrils with a small medial projection of the rim, spiracle posteriorly directed, and submarginal papillae scattered lateroanteriorly in tadpoles from Trinidad ( Fig. 29 in Kenny 1969) and Colombia ( Fig. 18 in Lynch 2006), absent in those from Peru ( Duellman 2005); tail tip pointed in tadpoles from Panamá ( Savage 1960); P2 shorter than P1 and, according to Figs. 1 and 2 snout sloped, and biseriate marginal papillae in tadpoles from Mexico ( Savage 1960); body ovoid in tadpoles from Ecuador ( Duellman 1978) and from Peru ( Duellman 2005); LTRF 2(2)/3[1] in tadpoles from Venezuela ( Rada de Martinez 1990); marginal papillae uniseriate, but frequently biseriate posteriorly in tadpoles from Mexico ( Ford & Scott 1996); posterior sheath broadly V-shaped and ventral fin convex in tadpoles from Peru ( Duellman 2005).

Figures

FIGURE 1. Larval amphibian habitat in Central Amazonia. (A) isolated forest pond, (B) streamside pond, (C) forest floor, (D) bromeliad, (E) treehole (with male Trachycephalus cunauaru), (F) stream, (G) river (blackwater), (H) várzea floodplain lake with floating meadows, and (I) igapó floodplain lake. Pictures by Marcelo Gordo (A, B, D, E, F, G, H) and LS (C, I).

FIGURE 2. Walter-Lieth climate diagram of Manaus representing mean monthly temperature (red line, left axis) and precipitation (blue line, right axis) from 1961 to 1990. Data from INMET, Instituto Nacional de Meteorologia (http://www.inmet.gov. br/portal/index.php?r=clima/graficosClimaticos, accessed October 4, 2015)

FIGURE 9. Tadpole of Rhinella marina (LCS 649) at Stage 37: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).

FIGURE 18. Tadpole of Boana fasciata (CZPB 199/448) at Stage 35: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).

FIGURE 29. Tadpole of Dendropsophus parviceps (LCS 619) at Stage 33: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) oral disc (scale = 1 mm).