Leptobrachium smithi (Matsui, Nabhitabhata & Panha, 1999)

Raj, Prudhvi, Vasudevan, Karthikeyan, Dutta, Sushil Kumar, Sahoo, Gunanidhi, Mahapatra, Susmita & Sharma, Richa, 2023, Larval morphology of selected anuran species from India, Alytes 39 - 40, pp. 1-140 : 53-57

S12. Leptobrachium smithi (Matsui, Nabhitabhata & Panha, 1999) ( fig. 26‒27 )

Larval series examined. WT 053‒055.231109 ( Kwanpui stream, Aizwal, Mizoram, India; 23.97097 N, 92.69192 E); WT 057‒058.231109 (Sihhmui stream, Aizwal, Mizoram, India; 23.79973 N, 92.64905 E). Tadpoles were collected in first-order streams with moderate water current. Substratum of the stream was sandy with no vegetative growth .

Notes. The collected tadpoles were reared ex-situ until metamorphosis for taxonomic verification. External morphological description for tadpoles of this species from specimens collected from India was made by Sahu (1994) and currently fits in the current description. However, the species is known to occur from a wide geographical area and species identity of tadpoles described by Matsui et al. (1999) and Inthara et al. (2005) must be verified.

External morphology. Description of a tadpole at Gosner stage 37. Body ovoid and globular in dorsal and lateral perspectives ( fig. 26a‒b ). Body length 38.2 % of total length maximum body diameter at the centre of abdomen. Snout rounded in dorsal and lateral perspectives. Eyes large; located and oriented dorsolaterally; distance between eye and nostril 43.3 % of distance between eye and snout. Nostril opening reniform, closer to eye than to snout; placed parallel to eye in dorsal view; inter-narial distance is 56 % of inter-orbital distance. Spiracle sinistral; inner wall of tube completely formed but attached to body wall; tube orientation posterolateral, its opening located below the medial and above the lateral side of venter. Distance between spiracle and snout 61.4 % of body length. Opening of vent tube dextral with right wall displaced dorsally and anteriorly. Tail tip rounded; musculature greatest at body-tail junction tapering beyond. Dorsal fin originating at junction between body tail, ventral fin originating at ventral terminus; dorsal and ventral fins of equal height. Maximum height of caudal fin at mid length of tail. Height of tail muscle 84 % width of tail muscle at body-tail junction. Tail (caudal) musculature accounting for 58.7 % of height of tail. Lateral line not conspicuous. Glands absent on outer integument.

Oral disc near-ventral in location ( fig. 26c ). Rostral width of oral disc 35.8 % of maximum body width, not emarginated at lateral commissures; single row of marginal papillae spread on both labia and at lateral commissures with a narrow dorsal gap; ventral labium lobed medially; five to six submarginal papillae at lateral commissures; both labia of equal size. Labial tooth row formula A5(2‒5)/P6(1‒6); about six to eight small labial tooth rows oriented laterally at lateral commissures; A1 smallest and A5 longest tooth rows on anterior labium; P1, P2, and P3 labial tooth rows of equal size with P4 and P5 decreasing in size on posterior labium; lateral commissures of P6 labial tooth rows curved inwards. Jaw sheaths well developed, both jaw sheaths heavily keratinized. Jaw sheath margins uniformly serrated with large serrations; supra-rostrodont inverted ‘V’ shape with long lateral arms; infra-rostrodont U-shaped, concave medially.

Measurements of 34 tadpoles at various Gosner stages (25‒35, 37) are given in tab. 12 .

Coloration. In life, dorsal body and tail dirty yellow speckled with few medium-sized blotches of melanophores on dorsum. Ventral integument dirty yellow and transparent with gut coils visible; Caudal fin musculature with two large dark spots at anterior end. Dorsal and ventral fins translucent. Spiracle, oral disc and vent tube translucent with no melanophores.

Buccopharyngeal morphology. Buccal roof ( fig. 27a ). Prenarial arena of roof smooth with no pustules. Internal nares transverse; directed medially; gap between nares narrow; about less than half the length of a nare; anterior narial wall pustulose with a few pustules; posterior wall tall, smooth and valvular with a tall narial projection near medial end. Postnarial arena with seven papillae; three pairs present directly behind nares; other papilla present medially; papillae arranged in an inverted ‘V’; shortest papilla medially at anterior end, and longest papillae at lateral corners; surface of papillae rugose. Median ridge papilla triangular with a trifid tip. A long, bifid lateral ridge papilla present on each side perpendicular to median ridge. BRA well defined with eight to nine pairs of long conical papillae present on lateral border of roof; about 50 tiny pustules uniformly spread across BRA. Glandular zone narrow and prominent with numerous secretory pits medially. Dorsal velum margin raised and discontinuous with many tall projections.

Buccal floor ( fig. 27b ). Prelingual arena composed of three pairs of palps; tiny anterior palp situated slightly anterior to posterolateral margin of jaw sheath; two laterally dilated pustulated palps located dorsally and ventrally at posterolateral margin of jaw sheath; dorsal palp broadly dilated; ventral palp with five long finger projections; a pair of papillae located posteromedially between the two posterior palps on jaw sheath. Tongue anlage broad; lingual papillae absent. BFA well defined by 25 pairs of BFA papillae; BFA papillae beginning posterior to tongue anlage run parallel to mesad plane of floor; papillae not converging at posterior end; BFA papillae conical, tall and pointed with a few branched; BFA composed of 70‒80 pustules spread across arena mainly concentrated at posterior end. Buccal pockets narrow and transverse, oriented 45 degrees to mesad; pocket papillae absent. Region lateral to BFA free of any pustules. Ventral velum wide and sinuate; margin with 14 projections; on each side, outer four projections smaller and widely spaced, and inner three projections longer and concentrated around centre; median notch prominent. Glottis exposed posterior to ventral velum.

Figures

Figure 26. Leptobrachium smithi, Gosner stage 37. External morphology: (a) Lateral view, (b) Dorsal view, (c) Ventral view. Scale = 10 mm.

Figure 27. Leptobrachium smithi, Gosner stage 37. Buccopharyngeal region: (a) Buccal roof, Alcian Blue stained photograph, ventral view, scale = 1 mm, (b) Buccal floor, Alcian Blue stained photograph, ventral view, scale = 1 mm.