Euphlyctis cyanophlyctis ( Schneider, 1799 )

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 : 19-22

S4. Euphlyctis cyanophlyctis ( Schneider, 1799) ( fig. 10‒11 )

Larval series examined. WT 017.2109 ( Mamidi Sala , Narjunasagar Srisailam Tiger Reserve, Andhra Pradesh, India; 16.06495 N, 78.91183 E); WT 026 and 031.10609 ( Beman waterfalls, Javadi Hills, Vellore Tamil Nadu, India; 12.60535 N, 78.86891 E); W T029.10609 ( Beman waterfalls, Javadi Hills, Vellore Tamil Nadu, India; 12.60533 N, 78.86893 E). Tadpoles of this species were collected in small streams with little or no water current. The substratum of the stream was muddy or with gravel.

Notes. The taxonomic identity of the tadpoles was based on a partial sequence of 16S rRNA (OQ079486) generated from the tadpole voucher WT 017. The sequence showed a 1 % sequence divergence compared to the published Genbank sequence ( AB290419 ) from a taxonomically identified specimen of Euphlyctis cyanophlyctis . Larval descriptions of morphology for tadpoles of this species were made by Mohanty-Hejmadi & Dutta (1979), Das (1994), Khan & Mufti (1995), Khan (1997, 2003 d) and Ray (1999). However, taxonomic uncertainty exists regarding these descriptions due to the wide distribution of the species.

External morphology. Description of a tadpole at Gosner stage 36. Body ovoid and globular in dorsal and lateral perspectives ( fig. 10a‒b ). Body length 38.4 % of total length; maximum body diameter attained at posterior end of body. Snout pointed in dorsal and rounded in lateral perspectives. Eyes large, located dorsolaterally and oriented laterally; distance between eye and nostril 42.8 % of distance between eye and snout. Opening of nostril reniform, closer to eyes than to snout, placed wide apart and parallel to eye in dorsal perspective; inter-narial distance 48.8 % of inter-orbital distance; distance between nostril and snout 26.2 % of body length. Spiracle sinistral and short; inner wall of tube formed but attached to body wall; tube orientation posterolateral, its opening located below the median and above the venter on lateral side of body. Distance between spiracle and snout 63.1% of body length. Vent tube opening dextral, with aperture not connected to ventral fin. Tail tip acute; musculature linear till 1/3 rd length of tail, after which it starts to taper. Dorsal fin originating at body-tail junction, ventral fin originating at ventral terminus; dorsal fin wider and more concave than ventral fin. Maximum tail height at about mid-length. Height of tail muscle 1.37 times of width at body-tail junction. Tail (caudal) musculature accounting for 61 % of height of tail. Lateral line along snout and lateral sides of body and tail fin. Glands absent on outer integument.

Oral disc nearly ventral in location ( fig. 10c ). Rostral width of oral disc 24.3 % of maximum body width, emarginated, not visible dorsally; single row of marginal papillae spread on lateral commissures of oral disc; gaps in distribution of marginal papillae seen medially on both labia; submarginal papillae none; both labia of equal size. Labial tooth row formula A1/P2. Order of lengths of labial tooth rows P1 = P2> A1. Jaw sheaths well developed with heavy pigmentation. Both jaw sheath margins with medium sized uniform serrations; supra-rostrodont longer than wide, convex with median region protruding towards posterior; infra-rostrodont U-shaped, convex laterally and concave medially.

Measurements of 22 tadpoles of various Gosner stages (28, 31, 34‒36, 38‒40, 42) are given in tab. 4 .

Coloration. In life, dorsal body olive with many melanophores. Flanks comparatively darker than dorsum. Ventral integument opaque and silvery white. Muscle region of tail dirty yellow with tiny melanophores extending from body-tail margin to tail tip. Both fins transparent with tiny melanophores dotted evenly. Spiracle was pigmented. Oral disc and vent tube devoid of melanophores.

Buccopharyngeal morphology. Buccal roof ( fig. 11a‒b ). Prenarial arena of roof smooth with no pustules. Internal nares transverse, oriented posteromedially; gap between nares narrow and about half the length of nare; anterior narial wall pustulose with few tiny pustules and a pustulose papilla at lateral corner; posterior wall smooth and valvular with region near to medial taller. Postnarial arena with three conical papillae arranged linearly immediately posterior to narial wall; papillae of medium height, with papillae closer to medial plane longer than papillae at lateral corners. Papilla on anterior narial wall and anterior papilla of postnarial arena of equal height. Median ridge papilla triangular with a papillated tip. Two lateral ridge papillae present on each side of lateral wall perpendicular to medial papilla; anterior lateral ridge papilla conical and short; posterior papilla broad with an uneven margin. BRA demarcated with five pairs of long conical papillae on lateral border of roof; about 40 tiny pustules spread in BRA. Glandular zone thick and prominent with secretory pits spread uniformly. Dorsal velum moderately tall, with many tiny projections present on velum.

Buccal floor ( fig. 11c‒d ). A single bifid palp on each side of the posterior lateral corners of the prelingual arena. Each palp divided into two equal long flattened projections with a smooth margin. No pustules in prelingual arena. Tongue anlage broad and elevated; a pair of smooth lingual papillae present; each lingual papilla tubular and papillated at the tip. BFA well defined; entire BFA smooth; 10 long conical papillae beginning parallel to mesad of BFA and passing posterolateral, converging posteriorly; most posterior BFA papilla largest; no pustules or papillae recorded on BFA. Buccal pocket opening broad and transversely arranged; one pre or one post pocket papilla present. Ventral velum margin composed of spicules with about four projections on each side; all projections on either side widely placed and of equal size. Median notch absent. Glottis exposed behind velum.

Denticles ( fig. 11e ) widely spaced and strongly curved at apex. Oral angle straight except for curved apex; sheath broad; head deeply curved and not cusped.

Each serration ( fig. 11f ) on jaw sheath with a short base and a triangular head.

Figures

Figure 10. Euphlyctis cyanophlyctis, Gosner stage 38. External morphology: (a) Lateral view, (b) Dorsal view, (c) Ventral view. Scale = 10 mm.

Figure 11. Euphlyctis cyanophlyctis, Gosner stage 37. Buccopharyngeal and denticles: (a) Buccal roof, Scanning Electron Microscopy photograph, scale =.2 mm, (b) Buccal roof, Alcian Blue stained photograph, ventral view, scale = 1 mm, (c) Buccal floor, Scanning Electron Microscopy photograph, scale = 0.2 mm, (d) Buccal floor, Alcian Blue stained photograph, ventral view, scale = 1 mm, (e) Individual denticles, scale = 0.02 mm, (f) Jaw sheath serrations = 0.01 mm.