Uperodon systoma ( 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 : 65-67

S15. Uperodon systoma ( Schneider, 1799) ( fig. 32‒33 )

Larval series examined. WT 097 and WT 116 ( North Orissa University ( NOU), Baripada, Odisha, India; 21.929389 N, 86.765389 E). Tadpoles were reared from eggs collected on the university campus. In nature, tadpoles were found in small temporary pools and water ditches during early monsoon rains .

Notes. The taxonomic identity of the tadpoles was confirmed by rearing the tadpoles in ex-situ conditions. Detailed descriptions of external morphology for tadpoles of this species were published by Mohanty-Hejmadi et al. (1979) and Ray (1999), and the current description fits these descriptions.

External morphology. Description of a tadpole at Gosner stage 32. Body rounded with a truncated anterior and a tapering posterior end in dorsal perspective; body triangular and depressed with a rounded anterior and a broadly rounded posterior in lateral perspective ( fig. 32a‒b ). Body length 36.5 % of total length; maximum body diameter at the centre of abdomen. Snout broad and truncate in dorsal perspective and acutely rounded and flattened in lateral perspective. Eyes moderate; located, and oriented laterally; distance between eye and nostril 64 % of distance between eye and snout. Nostril opening (imperforate) depressed; closer to snout than to eye; placed on either side along the medial of dorsum; inter-narial distance 21.1 % of inter-orbital distance. Large spiracle located medially on ventral side; inner wall of tube not formed. Vent tube opening medial and imbedded into ventral fin. Tail tip sharply pointed (flagellated); musculature broad at body tail junction and linear till mid-length of tail, tapering beyond. Dorsal fin originating anterior to junction between body tail, ventral fin originating at ventral terminus; ventral fin wider than dorsal fin; maximum tail height at mid-length. Height of tail muscle 1.21 times width of tail muscle at body-tail junction. Tail (caudal) musculature accounting for 43 % of height of tail. Lateral line not visible. Glands absent on outer integument.

Oral opening anterior in location ( fig. 32c ); opening not emarginated; and visible dorsally; marginal or submarginal papillae absent; upper labial margin smooth with slight convexity medially and lateral commissures having a bulge; lower labium with a medial cleft. Keratinized structures absent.

Measurements of 25 tadpoles at various Gosner stages (27‒28, 30, 32, 40‒45) are given in tab. 15 .

Coloration. Tadpoles fixed in 4 % formalin and preserved in 30 % ethanol. Dorsal body brown with numerous tiny brown melanophores. Ventral integument dirty yellow, translucent and rarely spotted; gut coils visible. Tail musculature brown and spotted; dorsal and ventral fins transparent and spotted with tiny melanophores at anterior end; ventral fin sparsely spotted. Vent tube translucent and dotted with few melanophores.

Buccopharyngeal morphology. Buccal roof ( fig. 33a‒b ). Prenarial arena of roof smooth with one broad papilla located medially. Internal nares round; gap between nares narrow, about half the length of a nare; anterior narial wall low; three broad papillae on posterior wall, two short papillae at lateral corner and a tall papilla near to medial. Postnarial arena with a tall papilla located medially. Medial ridge papilla tall with a bifurcate tip; margin of papilla rugose. Lateral ridge papillae absent. BRA defined by three BRA papillae on posterior lateral corner of the roof; 20 pustules spread across anterior region of BRA. Glandular zone wide and prominent; secretory pits present at posterior corner. Dorsal velum margin tall and continuous.

Buccal floor ( fig. 33c‒d ). Prelingual arena smooth and composed of a dilated palp on each posterior lateral corner of the prelingual arena; palps dilated and broad with rugose margin, and oriented anteromedially. Tongue anlage broad; lingual papillae absent. BFA well defined; 10 pairs of conical papillae beginning posterior to buccal pockets converging posteromedially; BFA papillae long and conical; few papillae bifid with a rugose surface; BFA smooth with no pustules. Buccal pocket opening broad, deep and obtuse; a large, broad pre-pocket papilla; few pustules below posterior margin of buccal pockets. Ventral velum margin smooth, with about eight projections spaced far apart. Glottis exposed medially on ventral velum.

Figures

Figure 32. Uperodon systoma, Gosner stage 32. External morphology: (a) Lateral view, (b) Dorsal view, (c) Ventral view. Scale = 10 mm.

Figure 33. Uperodon systoma, Gosner stage 32. Buccopharyngeal region: (a) Buccal roof, Scanning Electron Microscopy photograph, scale = 0.2 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.