Duttaphrynus himalayanus ( Günther, 1864 )

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 : 11-15

S2. Duttaphrynus himalayanus ( Günther, 1864) ( fig. 6‒7 )

Larval series examined. WT 004.27608 ( Barot forest guest house, Palampur, Himachal Pradesh, India; 32.09218 N, 76.85088 E) ; WT 028.041009 ( Baran nala, Askot WLS, Uttarakhand, India; 29.86873 N, 80.37192 E) ; WT 035.29608 ( Ghar nala, Bir, Palampur Himachal Pradesh, India; 32.05299 N, 76.71197 E) ; and WT 160.2208 ( Jolib , Askot WLS, Uttarakhand, India; 29.86873 N, 80.37192 E) . Tadpoles of this species were collected in shallow side pools, water puddles and side streams with little or no water current. The substratum of the pools was sandy with little or no emergent vegetation. Algal growth was very minimal.

Notes. The taxonomic identity of the tadpoles was confirmed by partial sequence of 16S rRNA (OQ079485) generated from tadpoles of the series WT 160. The sequence showed about 1 % sequence divergence compared to the published Genbank sequence ( KT991345 ) from taxonomically identified Duttaphrynus himalayanus . Tadpoles of this species were described by Annandale (1906, 1912), Bhaduri (1944 b), Ray (1999) and Khan (2001, 2006).

External morphology. Description of a tadpole at Gosner stage 38. Body ovoid and globular in dorsal and lateral perspectives ( fig. 6a‒b ). Body length 37.5 % of total length; maximum body diameter at centre of abdomen. Snout rounded in dorsal and lateral perspectives. Eyes large, located and oriented dorsolaterally; distance between eye and nostril 35 % of distance between eye and snout. Nostril opening elliptical, closer to eye than to snout; placed parallel to eye in dorsal view; inter-narial distance 43.2 % of inter-orbital distance, distance between nostril and snout 20.3 % of body length. Spiracle sinistral and short; inner wall of tube not formed; tube orientation posterolateral, its opening located below the medial and above the lateral side of venter. Distance between spiracle and snout 56.2 % of body length. Opening of vent tube medial with a wide aperture. Tail tip broadly rounded; musculature linear on first third length of tail, tapering beyond. Dorsal fin originating at junction between body tail, ventral fin originating at ventral terminus; maximum height of caudal fin at distal end of tail, dorsal and ventral fins of equal heights. Height of tail muscle 1.33 times width of tail muscle at body-tail junction. Tail (caudal) musculature accounting for 43.6 % of height of tail. Lateral line visible. Glands absent on outer integument.

Oral disc anteroventral in location ( fig. 6c ). Rostral width of oral disc 42.5 % of maximum body width, emarginated, not visible dorsally; single row of marginal papillae on labia and lateral commissures; marginal papillae broadly interrupted on both labia medially; two rows of submarginal papillae at lateral commissures; both labia of equal size. Labial tooth row formula A2(2)/P3; A1 longest, A2 divided medially; P1 slightly shorter than P2, P3 the smallest labial tooth row on posterior labium. Order of lengths of labial tooth rows A1> P2> A2> P1> P3. Jaw sheaths well developed, both jaw sheaths moderately keratinized. Jaw sheath margins uniformly serrated with small fine serrations; supra-rostrodont longer than wide, with thin and convex extended lateral process; infra-rostrodont U-shaped, convex laterally and concave medially.

Measurements of 15 tadpoles of various Gosner stages (33‒34, 36‒40) are given in tab. 2.

Coloration. In life, dorsal body and flanks black with numerous dark spots. In lateral perspective, flanks iridescent black. Ventral integument translucent with gut coils visible. Musculature of caudal fin black with tiny melanophores; dorsal and ventral fins translucid black mottled with tiny melanophores evenly along its surface. Gular and belly regions translucent with gut coils visible; vent tube dark grey.

Buccopharyngeal morphology. Buccal roof ( fig. 7a‒b ). Prenarial arena of roof with a single pustulated ridge located medially. Internal nares transverse, oriented anteromedially; gap between nares narrow, about half the length of nare; anterior narial wall pustulose with few tiny pustules spread evenly; posterior wall tall, smooth and valvular, without pustules. Postnarial arena with five pairs of papillae arranged in two rows in an inverted ‘V’ oriented anteromedially; first row consisting of three stubby papillae on each side and two long conical papillae on second row behind; first papilla in second row located towards medial plane longest. Median ridge papilla triangular with a pustulated margin and bifid tip. Lateral ridge papillae bifid, pustulose and located perpendicular to median ridge papilla. Buccal roof arena (BRA) demarcated with three pairs of long conical papillae on lateral border of roof; about 20 tiny pustules spread across BRA. Glandular zone thick and prominent, with secretory pits distributed throughout the zone. Dorsal velum smooth and continuous converging posteriorly, its margin at posterior end with few tiny projections.

Buccal floor ( fig. 7c‒d ). Prelingual arena smooth, with a dilated palp on each side of posterior lateral corners of jaw sheath. Many pustules on margin of each dilated palp. Tongue anlage low; broader at anterior end and tapering towards posterior end; two pairs of long conical lingual papillae. BFA well defined; 14‒16 short conical papillae beginning from middle of BFA and converging posterior-laterally; all BFA papillae of equal size; a few papillae present in lateral region between BFA papillae and ventral velum; BFA with about 15 pustules. Buccal pocket opening narrow; few pustules between tongue anlage and buccal pockets; pre-pocket papillae absent. Ventral velum margin with many spicules bearing about 14 projections. Outer two projections on either side widely placed, and five projections on either side concentrated at the centre. Median notch prominent. Glottis exposed posterior to ventral velum.

Denticles ( fig. 7e ) closely packed and strongly curved towards mouth at the apex. Oral angle obtuse with head curved; sheath narrow followed by body, which is slightly broader; tip of head broadly curved; 8‒12 short and moderately rounded cusps on each denticle.

Each serration ( fig. 7f ) on jaw sheath with a wide base and a rounded head.

Figures

Figure 6. Duttaphrynus himalayanus, Gosner stage 37. External morphology: (a) Lateral view, (b) Dorsal view, (c) Ventral view. Scale = 10 mm.

Figure 7. Duttaphrynus himalayanus, Gosner stage 37. Buccopharyngeal and denticles: (a) Buccal roof, Scanning Electron Microscopy photograph, scale = 0.2 mm, (b) Buccal roof, Alcian Blue stained photograph, ventral view, scale = 0.5 mm, (c) Buccal floor, Scanning Electron Microscopy photograph, scale = 0.2 mm, (d) Buccal floor, Alcian Blue stained photograph, ventral view, scale = 0.5 mm, (e) Individual denticles, scale = 0.02 mm, (f) Jaw sheath serrations = 0.01 mm.