Duttaphrynus melanostictus ( Schneider, 1799 )

S3. Duttaphrynus melanostictus ( Schneider, 1799) View in CoL ( fig. 8‒9 View Figure 8 View Figure 9 )

Larval series examined. WT 159.11411(Wildlife Institute of India ( WII), Dehradun , Uttarakhand, India; 30.28414 N, 77.97547 E). Tadpoles of this species were collected along the shallow banks of a lake in WII campus. In other locations, tadpoles of this species were found to inhabit water puddles, streams (first-order) with little or no water current. The substratum of the pools was sandy with a good proportion of gravel and with little emergent vegetation GoogleMaps .

Notes. The taxonomic identity of the tadpoles was confirmed by rearing them from eggs collected from taxonomically identified adults of Duttaphrynus melanostictus at Wildlife Institute of India campus. Tadpole descriptions for this species were made by number of authors. However, further taxonomic validation that this species was involved in all cases is needed, given the wide geographical distribution currently credited to this species.

External morphology. Description of a tadpole at Gosner stage 33. Body ovoid and globular in dorsal and lateral perspectives ( fig. 8a‒b View Figure 8 ). Body length 40.3 % of total length; maximum body diameter at the middle of body. Snout rounded in dorsal and lateral perspectives. Eyes large, located and oriented dorsolaterally; distance between eye and nostril 31.8 % of distance between eye and snout. Nostril opening reniform with elevated rim, closer to eye than to snout, placed parallel to eye in dorsal view; inter-narial distance 52 % of inter-orbital distance; distance between nostril and snout 20 % of body length. Spiracle sinistral; inner wall of tube not completely formed; tube orientation posterolateral, its opening located below the medial and above the venter of lateral side. Distance between spiracle and snout 70.8 % of body length. Vent tube opening median, short. Tail tip round; height of tail musculature greatest at body tail junction, after which it tapers to tail tip. Dorsal fin originating at body tail junction, ventral fin originating at ventral terminus; both tail fins of equal height for most of their length. Maximum tail height at mid length. Height of tail muscle about 1.27 times that of width of muscle at tail-body junction. Tail (caudal) musculature accounting for 37 % of height of tail. Dermal pores of lateral lines on body faintly visible. Glands absent on outer integument.

Oral disc anteroventral in location ( fig. 8c View Figure 8 ). Rostral width of oral disc 62 % of maximum body diameter, emarginated, not visible dorsally; single row of marginal papillae spread on lateral commissures of oral disc but none seen on both labia; two to three submarginal papillae at lateral commissures; both labia of equal size. Labial tooth row formula A2(1)/P3. Order of lengths of labial tooth rows A1> P1> P2> P3> A2. Jaw sheaths very feeble, both moderately keratinized. Jaw sheath margins with small uniform serrations; supra-rostrodont convex, longer than wide, with median region slightly broad and protruding posteriorly, moderately keratinized and tapering to a long thin lateral process; infra-rostrodont V-shaped with a concave median region.

Measurements of 14 tadpoles at various Gosner stages (27‒29, 31‒32, 34) are given in tab. 3.

Coloration. In life, dorsal body black with many closely spaced tiny melanophores on both inner and outer integuments. In lateral perspective, flanks spotted with several tiny melanophores. Ventral integument olive colored, transparent with gut coils visible; ventral side spotted with several tiny melanophores. Both fins transparent and dorsal fin spotted in its anterior portion. Entire tail muscle spotted with several tiny melanophores, mostly along posterior region of tail. Spiracle, oral disc and vent tube translucent, dotted with few melanophores.

Buccopharyngeal morphology. Buccal roof ( fig. 9a View Figure 9 ). Prenarial arena of roof with a triangular transverse ridge bearing tiny papillae on lateral corners. Internal nares transverse; oriented anteromedially; gap between nares narrow, about half length of nare; anterior narial wall pustulose with few tiny pustules and no papilla; posterior wall tall, smooth and valvular, without pustules. Postnarial arena with three pairs of papillae arranged in an inverted ‘V’ oriented anteromedially. Second and third postnarial papillae conical and pustulose, second papilla being the longest; first papilla stubby. Median ridge papilla triangular with a smooth margin and bifid tip. A single trifid pustulose lateral ridge papilla perpendicular to median ridge. BRA demarcated with three pairs of long conical papillae on lateral border of the roof; about 30 tiny pustules spread across BRA. Glandular zone thick and prominent. Dorsal velum slightly raised and continuous, with a few tiny projections medially.

Buccal floor ( fig. 9b View Figure 9 ). Prelingual arena composed of a single dilated palp on each side of posterior lateral corners of jaw sheath. Each palp divided into two equal wide projections with many pustules on the margin. Tongue anlage round and low; two pairs of smooth lingual papillae, one at centre projecting inwards and other on lateral corners of tongue anlage, projecting outwards. BFA well defined; anterior region of BFA smooth; six long conical papillae beginning from middle of BFA and passing posterolateral; second BFA papilla largest and bifid; posterior region of BFA with about 20 pustules. Buccal pocket opening narrow and transversely arranged; few pustules in region between tongue anlage and buccal pockets; pre-pocket papillae absent. Ventral velum smooth with about 10 projections. Outer two projections on either side widely placed, all others concentrated at the centre. Median notch not prominent. Glottis exposed way behind ventral velum.

Each serration ( fig. 9c View Figure 9 ) on jaw sheath with a wide base and a rounded head.

Denticles ( fig. 9d View Figure 9 ) closely packed and strongly curved towards mouth at apex. Oral angle slightly obtuse; sheath narrow; body slightly broader. Tip of head broad with 10‒12 long and moderately rounded cusps on each denticle.