Theloderma albopunctatum, (Liu & Hu, 1962) (Liu & Hu, 1962)

Ginal, Philipp, Schmitz, Lisa M. & Rödder, Dennis, 2022, Larval description of Theloderma albopunctatum (Liu & Hu, 1962) (Anura: Rhacophoridae) from Northern Vietnam, with comparison between the North-Vietnamese and North-eastern Thai clades, Zootaxa 5214 (4), pp. 595-599 : 597-598

Tadpole description.

The description of the tadpoles is based on one specimen at Stage 31. Body shape ( Fig. 1A ) oval and slightly elongated (MBW/BL 0.69); snout short and slightly pointed (RED/BL 0.30, BWN/BWE 0.65); nares small, rounded, located on dorsal side of body with lateral orientation, situated closer to snout than to eyes (RND/RED 0.44); eyes large (ED/BL 0.10), located on dorsal side of body with lateral orientation; internarial distance slightly smaller than interorbital distance (IND/IOD 0.83); single, sinistral spiracle not visible from dorsal view. Body moderately depressed in lateral view (MBH/MBW 0.75) with rounded snout; spiracle located below the longitudinal axis, on second half of body (RSD/BL 0.65), inner wall free from body, opening is round, spiracle tube short; maximum body height from front of base of tail on dorsal side to second half of body of ventral side; tail slightly longer than body, rounded at tip (TAL/BL 1.22, TAL/TL 0.57); musculature well developed (TMH/MTH 0.58, TMW/MBW 0.27); “V”-shaped myosepta visible along whole length of tail, most intensely at first half of tail; upper fin originates dorsally at base of tail, higher than lower fin (UF 1.97 mm, LF 1.65 mm); vent tube has medial position, emerges sagittal from abdomen between two hind limb buds, ends with short rounded opening. Oral disc ( Fig. 1B ) elliptical, located ventrally, size nearly half of body width (ODW/ MBW 0.40); small, rounded papillae located marginal at lower jaw sheath, absent at upper labium, except most lateral part; numbers of marginal papillae range from 54 up to 69; submarginal papillae present in some individuals, can also be absent, ranging from 0 up to 14 per individual; some papillae develop labial teeth; anterior labium contains one marginal tooth row, two tooth rows on each side of mouth; outermost row shorter than inner row; posterior labium contains three tooth rows; small medial gap in innermost tooth row, rows get shorter to outside; labial tooth row formula 3(2-3)/3(1); jaw sheaths black, with serrations on edges; upper jaw sheath wider and higher than lower jaw sheath, indentation at top.

Coloration in life. Tadpoles are ashy grey at body and tail; venter is slightly paler; tail translucent with dark pigmentation; vent tube unpigmented ( Fig. 1C ).

Colouration in preservative. Snout and dorsum of tadpoles dark grey with most pigmentation on dorsum; light symmetrical patches barely pigmented on lateral side and anterior eyes; pigmentation decreases as well towards posterior; eyes also surrounded by dark colouration; ventral side of snout dark grey; light patches starting laterally run around whole body, sharply differentiated by roof shaped outlining of dark area starting in centre of ventral side of body, directs towards posterior; patch equally becomes much lighter towards posterior body; vent tube unpigmented; anterior tail, especially base, more pigmented than second half, tail slightly lighter; fins coloured in light grey, slightly transparent; developing hind limb buds unpigmented, whitish as well as medially oriented vent tube.

Measurements. All nine tadpoles are considered, and measurements are given in mm, as median (range): MBH 7.3 (6.7–8.2); BL 14.7 (14.1–16.3); MBW 10.0 (8.9–11.2); ED 1.5 (1.2–1.9); IND 2.3 (2.1–2.6); IOD 3.5 (3.1–4.5); UF 1.9 (1.8–2.1); LF 1.7 (1.5–1.9); MTH 5.6 (5.0–6.2); END 2.7 (2.3–3.1); ODW 3.8 (3.2–4.1); RND 2.0 (1.9–2.3); RSD 9.8 (8.7–11.2); TAL 18.7 (17.6–22.1); TL 32.3 (30.9–36.4); TMH 3.3 (2.8–3.6); TMW 2.8 (2.3–3.6); BWE 8.6 (7.9–9.6); BWN 5.7 (5.4–6.9); RED 4.5 (4.1–5.6); MBW/BL 0.67 (0.59–0.72); RED/BL 0.31 (0.29–0.34); ED/BL 0.10 (0.09–0.13); RND/ RED 0.45 (0.41–0.50); IND/IOD 0.61 (0.50–0.83); TMW/MBW 0.28 (0.23–0.36); MBH/MBW 0.74 (0.72–0.77); TAL/BL 1.23 (1.20–1.43); TAL/TL 0.57 (0.56–0.61); TMH/MTH 0.56 (0.52–0.60); ODW/MBW 0.38 (0.36–0.41); RSD/BL 0.67 (0.60–0.69); BWN/BWE 0.68 (0.63–0.78); marginal papillae 64 (53–69); submarginal papillae 5 (0–14).

Comparison to other Theloderma tadpoles. Tadpoles from north-eastern Thailand described by Chunskul et al. (2021) are very similar to tadpoles in this study, which were assigned to specimens originating from northern Vietnam. Body shape and colour are alike, and minor differences regarding LTRF [some Thai individuals showed LTRF 2(2)/2(1)] can be interpreted as ontogenetic variations. The comparison of body measurements suggests that, although most proportions are similar, northern Vietnamese tadpoles have shorter tails (TAL/BL about 10% smaller than in Thai tadpoles) and wider oral discs (ODW/MBW about 10% larger in tadpoles here studied).

Table 1 shows summarized descriptions of tadpoles of 15 Theloderma species. All Theloderma tadpoles share a robust appearance with a distinctly flattened body, dorsally oriented eyes and nostrils, and dark body colouration ranging from dark brown, grey, blue to black (except for T. laeve , which is mainly unpigmented, fleshy, pinkish). Furthermore, they show similar spiracles, vent tubes, oral disc positions and shapes of lower and upper jaw sheaths. Most tadpoles are easily distinguishable from those of T. albopunctatum by their LTRF. Twelve species (including T. vietnamense where the lowest LTRF corresponds to young tadpoles) have high LTRF with 4 or 5 upper tooth rows. Only three species share the LTRF 3/3 of T. albopunctatum . Among them, tadpoles of T. bicolor are larger at comparable stages (almost twice the total length of Thai T. albopunctatum tadpoles), while tadpoles of T. lateriticum are slightly smaller. The features analysed do not allow to distinguish tadpoles of T. asperum from those here studied.

We are grateful for the technical assistance of Morris Flecks and Ursula Bott. Further, we thank Nils Behr and Timo Hartmann for reviewing the manuscript as well as Dr. Florencia Vera Candioti for editorial support.

Figures

FIGURE 1. Theloderma albopunctatum from northern Vietnam: (A) tadpole at Stage 31 (ZFMK 103953) in dorsal, lateral, and ventral views (hind limb buds excluded to show the vent tube), (B) oral disc, frontal view, (C) tadpoles at stages 37 and 42 in life, (D) juvenile frog in life. Photographed by Morris Flecks and drawn by Lisa M. Schmitz.