Theloderma corticale ( Boulenger, 1903 )

Gawor, Anna, Chapuis, Simone, Pham, Cuong The, Nguyen, Truong Quang, Schmitz, Andreas & Ziegler, Thomas, 2012, Larval morphology of two species of the genus Theloderma (Tschudi, 1838) from Vietnam (Anura: Rhacophoridae: Rhacophorinae), Zootaxa 3395, pp. 59-64 : 62-63

Theloderma corticale ( Boulenger, 1903)

The following larval description of T. corticale is based on a single captive bred specimen in Gosner stage 32 (IEBR A.2011.6, GenBank accesssion number JX046476 ) preserved at the Amphibian Breeding Station in Hanoi ( Fig. 1 B), which derived from parents from Tam Dao National Park, Vinh Phuc Province, Vietnam.

Tadpole matching: for a specific assignment of the tadpole IEBR A.2011.6, its molecular 16S sequence was compared to that of an adult specimen (IEBR 3267, GenBank accesssion number JX046477 ) from Tam Dao National Park, Vinh Phuc Province, Vietnam, which largely agreed with the original description for T. corticale provided by Boulenger (1903). Comparison of the resulting 512 bp long fragment of the 16S rRNA between the adult and the tadpole showed a complete identity of the two sequences and therefore, an unambiguous assignment of this tadpole to the species T. corticale is guaranteed.

Colour pattern. Colouration in life: body uniform dark grey to black pigmented; dorsal and dorsolateral pigmentation of body more dense than on ventral side; skin of oral disc and throat dark greyish; gills and heart not visible; intestinal spiral region laterally and ventrally slightly brighter than dorsally; intestinal spiral yellowish to slightly reddish and visible through skin; blood vessels of intestinal spiral visible; vent tube and developing hind limbs whitish and unpigmented; tail musculature, whitish in basic colour, uniformly greyish pigmented; upper and lower tail fin opaque and greyish pigmented, except for unpigmented edges of both upper and lower tail fin; iris black ( Fig. 1 B).

Colouration in preservative: Under preserved conditions colour pattern and colouration the same as in living tadpole. Merely, the body of preserved tadpole became slightly brighter and skin more transparent.

Description in dorsal view. Body oval-shaped (maximum body width 0.72 of body length; body length 0.76 of tail length); snout round; eyes small (maximum eye diameter 0.11 of body length), dorsally located at end of first third of body and anterior directed; interpupilar distance 0.41 maximum body width; nares rounded, slightly rimmed, dorsally positioned and anterolaterally directed; nares in the middle between tip of snout and pupil (rostro-narial distance 1.03 of naro-pupilar distance); internarial distance 0.52 of interpupilar distance; tail musculature of remarkable size, widest at base (width of tail musculature at base 0.33 of maximum body width); spiracle sinistral in dorsal view ( Fig. 3 A).

Description in lateral view. Body slightly depressed in mouth and eye region before becoming round-bellied in region of intestinal spiral (maximum body height 0.67 of maximum body width); spiracle sinistral and ventrolaterally positioned in the middle of body; spiracle opening of remarkable size (1.8 mm in diameter (vertical axis), vertical slotshaped), oriented in posterior direction; inner wall of spiracle opening attached to body; vent tube ventromedially located directly at end of body between limbs; posterior part of vent tube coadunate with lower tail fin; musculature of tail at base remarkably developed (height of tail musculature at base 0.85 of maximum body height, and 0.75 times of maximum tail height). In lateral view, height of tail musculature from base to middle of tail half parallel before gradually tapering to the end of tail, not reaching the tail tip. Upper tail fin starts in the middle of last third of body length. Both, upper and lower tail fin slightly convex, nearly parallel. Upper tail fin slightly higher in the middle of tail length (maximum height of upper tail fin 1.42 of maximum height of lower tail fin) ( Fig. 3 B).

Oral disc. Anteroventrally positioned (oral disc width 0.30 of maximum body width); upper labium with a large medial gap; marginal papillae in corners of upper labium and on lower labium present; submarginal papillae absent; papillae finger-shaped, short and all of equal length; number of papillae> 100; labial tooth row formula: 4(2-4)/3(1); jaw sheaths black and serrated; lower jaw sheath M-shaped ( Fig. 3 C).

Measurements (in mm). BH 10.5; BL 21.9; BW 15.8; ED 2.5; IND 3.3; IP 6.4; LF 3.3; MTH 11.9; NP>100; NPD 3.6; ODW 4.8; RND 3.7; SS 14.4; TAL 29.0; TL 50.9; TMH 8.9; TMW 5.2; UF 4.7.

Although 23 species are currently recognised within the genus Theloderma , larval descriptions are available only for seven species (30.4% of the species number), namely T. asperum , T. bambusicolum , T. horridum , T. moloch , T. nebulosum , T. palliatum , and T. stellatum ( Leong & Lim 2003; Frost 2011; Rowley et al. 2011; Orlov et al. 2012).

According to Leong & Lim (2003), Rowley et al. (2011) and Orlov et al. (2012), the tadpoles of T. asperum , T. horridum , T. moloch , T. nebulosum , T. palliatum and T. stellatum as well as the herein described two tadpoles of T. bicolor and T. corticale share a similar colour pattern: uniform dark brown, greyish or black bodies. The larvae of T. bambusicolum are unpigmented, semi-transparent and whitish on dorsum ( Orlov et al. 2012).

Besides, the tadpoles of Theloderma bicolor and T. corticale can be distinguished from the remaining known Theloderma larvae by having different numbers of keratodont rows (thus, different labial tooth row formulae), which are 3(2-3)/ 3 in T. bicolor and 4(2–4)/3(1) in T. corticale , instead of 3(2-3)/3(1) in T. asperum , 4(2–4)/ 3 in T. bambusicolum , T. nebulosum , T. palliatum and T. stellatum , as well as in T. horridum and T. moloch ; however, in the latter two species sometimes also the tooth row formula 4(2–4)/3(1) can occur, which, in this case, is identical with the tooth row formula herein described for T. corticale (see Leong & Lim 2003; Rowley et al. 2011; Orlov et al. 2012).

Figures

FIGURE 1. Tadpoles in life in the Amphibian Breeding Station (Hanoi, Vietnam). A) Theloderma bicolor (2009) and B) Theloderma corticale (2010). Photos: Thomas Ziegler.

FIGURE 3. Drawings of the preserved tadpole of Theloderma corticale (stage 32) from the Amphibian Breeding Station (Hanoi, Vietnam). A) dorsal view (scale bar 10 mm), B) lateral view (part of lower tail fin including musculature cut for tissue sample; scale bar 10 mm) and C) oral disc (scale bar 1 mm). Drawings: A. Gawor.