Chiasmocleis hudsoni, Parker, 1940

Schiesari, Luis, Rossa-Feres, Denise De Cerqueira, Menin, Marcelo & Hödl, Walter, 2022, Tadpoles of Central Amazonia (Amphibia: Anura), Zootaxa 5223 (1), pp. 1-149 : 96-97

Chiasmocleis hudsoni

External morphology. Description based on nine tadpoles at Stage 33 (INPA-H 16958). Total length 11.5 ± 0.4 mm (N=9). Body rectangular in dorsal view and triangular/depressed in lateral view ( Fig. 62A, B ). Snout broad and bluntly rounded in dorsal view and rounded in lateral view. Eyes small, positioned and directed laterally. Nostrils not perforated until Stage 33. Mouth terminal ( Fig. 62C ). Anterior lip large, fleshy, covering the oral opening; posterior lip narrow, generally with the border arched. Jaw sheaths, papillae, and tooth rows absent. Spiracle single, long and wide, positioned ventromedially; distal border projecting over the vent tube. Vent tube dextral, 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, originating at the tail-body junction, convex; ventral fin shallow and convex. Tail tip pointed.

Colour. In preservative dorsum transparent brown with dark melanophores, venter whitish with melanophores on the anterior part; caudal musculature light brown; fins translucent; caudal musculature and fins with melanophores ( Rodrigues et al. 2008). In life dorsum transparent brown or orange, venter whitish and tail transparent ( Rodrigues et al. 2008).

Variation. External nostrils no perforated and dorsally positioned, consisting of a rounded whitish spot at Stages 41, 42 and 44 ( Rodrigues et al. 2008).

Metamorphs. Dorsum reddish brown with small white spots; one silver stripe from the snout to the dorsolateral region.

Natural history. Eggs are deposited amid roots in the soil or in fallen tree trunks near streamside or isolated ponds in terra-firme forests; tadpoles hatch at stages 26 and 27 and reach the pond after rainfall floods the nest ( Rodrigues et al. 2008). Clutches contain about 350 eggs ( Rodrigues et al. 2008). Tadpoles are found in the rainy season. In experiments tadpoles of C. hudsoni were preyed upon by dragonflies and fish ( Hero 1991).

Comments. Tadpoles of Chiasmocleis hudsoni from Central Amazonia were illustrated as C. cf. ventrimaculata by Hero (1990), and described as C. hudsoni by Rodrigues et al. (2008). These tadpoles differ from those herein characterized by presenting a spiracle that does not projected on the vent tube (Hero 1990), and a vent tube positioned along the ventral midline (Hero 1990; Rodrigues et al. 2008).

Figures

FIGURE 62. Tadpole of Chiasmocleis hudsoni (INPA-H 16958) at Stage 33: (A) lateral view, (B) dorsal view (scale = 10 mm), and (C) mouthparts (scale = 1 mm).