Rohanixalus shyamrupus ( Chanda and Ghosh, 1989 ) Biju & Garg & Gokulakrishnan & Chandrakasan & Thammachoti & Ren & Gopika & Bisht & Hamidy & Shouche, 2020

Biju, S. D., Garg, Sonali, Gokulakrishnan, G., Chandrakasan, Sivaperuman, Thammachoti, Panupong, Ren, Jinlong, Gopika, C., Bisht, Karan, Hamidy, Amir & Shouche, Yogesh, 2020, New insights on the systematics and reproductive behaviour in tree frogs of the genus Feihyla, with description of a new related genus from Asia (Anura, Rhacophoridae), Zootaxa 4878 (1), pp. 1-55 : 45

Rohanixalus shyamrupus ( Chanda and Ghosh, 1989) comb. nov.

Shyamrup’s Bubble-nest Frog

( Figs. 1–2 , 4 , 7 , 18–19 ; Tables 1 , 3 , 4 )

Original name and description. Philautus shyamrupus Chanda and Ghosh, 1989 . Chanda S. K. and Ghosh A. K. 1989. A new frog of the genus Philautus Gistel , from the proposed Namdapha Biosphere Reserve, Arunachal Pradesh, northeast India. Journal of the Bombay Natural History Society, 86: 215–217. Type. Holotype, ZSIC A 7944 (formerly ZSI-KZ 313), by original designation. Type locality. “Hornbill, Namdapha Tiger Reserve”, Arunachal Pradesh, India. Current status of specific name. Valid name as Rohanixalus shyamrupus ( Chanda and Ghosh, 1989) comb. nov.

Taxonomic remarks. Chanda & Ghosh (1989) originally placed this species in the genus Philautus . The original description, as well as Chanda & Sarkar (1997), did not compare this taxon with any known Philautus species from Eastern Himalayas or neighbouring regions, other than with unrelated ranid species ( Dubois 1999; Bossuyt & Dubois 2001). Based on the description and available photograph ( Chanda & Sarkar 1997), Bossuyt & Dubois (2001) suggested that the species is not a member of Philautus due to characters such as longitudinal bands or lines on the body or flanks, smooth chest and belly, extensive webbing, and lack of inner and outer metatarsal tubercles. They provisionally transferred it to the genus Chirixalus , without stating any potentially close taxa. We examined the holotype of Philautus shyamrupus and found that it represents a member of the genus Rohanixalus due to characters such as the presence of dorsolateral stripes and dorsal spots. We have further confirmed the identity and generic placement of Rohanixalus shyamrupus ( Chanda and Ghosh, 1989) comb. nov., both morphologically and phylogenetically, based on new topotypic and additional collections from Northeast India ( Figs. 1 , 2 ; Table 1 ).

Diagnosis. Small-sized adults (male SVL 18–21 mm, female SVL 24–25 mm) with a slender body; snout nearly pointed in dorsal view; dorsal colouration light to dark brown with a reddish tinge; the entire dorsum, lateral surfaces, and dorsal surfaces of limbs covered with fine dark brown speckles, some speckles clumping together to form dark and irregular blotches on the dorsum; a dark and continuous dorsolateral stripe starts from the tip of the snout, extends through the eyes, and reaches close to the vent on either side; lateral surfaces of the head, including tympanic region, darker than dorsum; foot webbing moderate, just above the second subarticular tubercle on either side of toe IV. Further, the eggs are light green in colour and laid in bubble nests.

Genetic divergence. For the mitochondrial 16S gene, Rohanixalus shyamrupus differs from other genetically known congeners ( Fig. 1 ) by average uncorrected genetic distance of: 9.4–10.1% from R. baladika , 8.2–10.2% from R. hansenae , 3.0–3.4% from R. senapatiensis , and 8.6–10.1% from R. vittatus . Some previously sampled populations from the geographically close Putao district in Kachin state of Myanmar (‘ Feihyla vittata ’ Group I of Aowphol et al. 2013; R. cf. shyamrupus in the present study, Fig. 1 ) are related to R. shyamrupus by 2.8% divergence. Further studies are required to ascertain the identity of Putao populations, as well as two additional unidentified lineages ( Rohanixalus sp. 1 and Rohanixalus sp. 2). For detailed intra-generic comparisons see Table 3 .

Distribution. Rohanixalus shyamrupus was originally described from Changlang district in the state of Arunachal Pradesh, India. In the present study, we genetically confirm the identity and phylogenetic relationship of the species based on topotypes from Namdapha Tiger Reserve, Changlang district. Additionally, this species is known from West Kameng district in Arunachal Pradesh; and Kohima and Peren districts of Nagaland. Previous reports of R. vittatus from Nagaland ( Romer 1951 “1949”; Kiyasetuo & Khare 1986) are likely to refer to this species.

Figures

FIGURE 1. Maximum Likelihood tree showing phylogenetic relationships among 124 representative taxa from all recognised genera of the subfamily Rhacophorinae. Relationships are inferred based on 1,937 bp of mitochondrial (12SrRNA, tRNAVAL, 16SrRNA) and nuclear (RHO and RAG1) genes. Numbers above and below the branches indicate Bayesian Posterior Probabilities and RAxML bootstrap support values, respectively.

FIGURE 2. A–B. DNA Barcoding based on mitochondrial 16S rRNA sequences: A. genus Feihyla; B. genus Rohanixalus gen. nov.; C. distribution of the new genus Rohanixalus. Images represent the corresponding species and their broad geographical ranges.

FIGURE 4. Distribution of genetically confirmed records of all known Feihyla and Rohanixalus members (indicated by circles) and their respective type localities (indicated by triangles). Numbers corresponding to each species are indicated alongside the distribution spots.

FIGURE 7. Members of the genus Rohanixalus. A. Dorsolateral view of R. hansenae from the type locality, Nong Khor, Thailand; B. dorsolateral view of R. marginis (holotype) from Perlis State Park chalets, Perlis, Peninsular Malaysia; C. dorsal view of R. cf. nauli, from Batang Gadis National Park, North Sumatra, Indonesia with a jelly-nest; D. dorsolateral view of R. cf. nauli, from Batang Gadis National Park, North Sumatra, Indonesia; E. dorsolateral view of R. cf. nauli, from Bukit Barisan Forest Park, North Sumatra, Indonesia; F. dorsolateral view of R. punctatus (Paratype, JBS 9274) from Gwa, Rakhine State, Myanmar (CC Public domain 3.0; AmphibiaWeb); G. dorsolateral view of R. vittatus from Rangat, Middle Andaman Islands, India; H. dorsolateral view of R. senapatiensis from Manipur, India; I. dorsolateral view of R. shyamrupus from Namdapha, Arunachal Pradesh.

FIGURE 18. Feihyla shyamrupus in preservation and life. A–G. Holotype, ZSIC A 7944 (formerly ZSI-KZ 313): A. dorsal view; B. ventral view; C. lateral view; D. lateral view of head; E. ventral view of hand; F. ventral view of foot; G. schematic illustration of webbing on foot; H–O. Topotypes from Northeast India, in life: H. dorsolateral view; I. dorsal view; J–K. dorsolateral view; L. enlarged view of skin over the tympanic region showing star-shaped speckles; M. ventral view; N. ventral view of hand; O. ventral view of foot.

FIGURE 19. Male advertisement calls of Feihyla shyamrupus recorded at Nagaland, India. A. Oscillogram of 10 s call segment; B. oscillogram of 1 s call segment; C. oscillogram of 0.1 s call segment; D. spectrogram of 0.1 s call segment.