Rohanixalus nauli (Riyanto and Kurniati, 2014) comb. nov. Nauli Bubble-nest Frog (Figs. 1–2, 4, 7, 15; Tables 1, 3, 4) Original name and description. Chiromantis nauli Riyanto and Kurniati, 2014. Riyanto A. and Kurniati H. 2014. Three new species of Chiromantis Peters 1854 (Anura: Rhacophoridae). Russian Journal of Herpetology, 21: 65–73. Type. Holotype, MZB.Amph.14.916, by original designation. Type locality. “Teluk Nauli, Sibolga, North Sumatra Province ”, Indonesia. Current status of specific name. Valid name as Rohanixalus nauli (Riyanto and Kurniati, 2014) comb. nov. Taxonomic remarks. This taxon was originally described from North Sumatra based on a single specimen. We examined the type specimen and found that this species is more closely related to members of the genus Rohanixalus than to Chirixalus. Further, R. nauli is morphologically similar to R. baladika described from West Sumatra (for detailed discussion see taxonomic remarks under R. baladika). Subsequent new collections from North and West Sumatra show that R. baladika and R. nauli are likely to represent a single species, with a shallow divergence of 0.2–0.6%. Phylogenetically, the populations from North and West Sumatra are nested in the genus Rohanixalus (Fig. 1). The dorsal colour and markings are also highly variable among the type specimens of R. baladika as well as new collections from regions across North and West Sumatra, especially the prominence of dorsal spots and dorsolateral stripes (Fig. 14) that were originally used to distinguish the two species (Riyanto & Kurniati 2014). We also report a Rohanixalus population from North Sumatra that was observed guarding a nest (Fig. 7), which is suggested as a possible behavioural synapomorphy for diagnosis of the genus Rohanixalus (e.g., Li et al. 2009; Hertwig et al. 2013; present study). Hence based on available evidence, we propose to formally reallocate Chiromantis nauli Riyanto and Kurniati, 2014 (= Chirixalus nauli) as Rohanixalus nauli (Riyanto and Kurniati, 2014) comb. nov. However, R. nauli is likely to be a junior subjective synonym of R. baladika, pending further investigation. Diagnosis. Small-sized adults (male SVL 20.9 mm), with slender body; snout subelliptical to nearly pointed in dorsal view; dorsal skin shagreened to sparsely granular; the entire dorsum, lateral surfaces, and dorsal surface of limbs covered with fine dark brown speckles (in the type), some speckles clumping together to form dark irregular blotches or reticulation on the dorsum; a pair of obscure dorsolateral stripes present in the type (stated as absent in the original description); foot webbing moderate, up to the second subarticular tubercle on either side of toe IV; eggs light green in colour and laid in bubble nests. Populations from north Sumatra were observed to have variable dorsal markings and degree of prominence of the dorsolateral stripes (Fig. 14). Genetic divergence. Sequence data from North and West Sumatra, potentially representing Rohanixalus nauli and R. baladika respectively, shows shallow divergence of 0.2–0.6%.1.2 Distribution. Rohanixalus nauli is currently known only from its type locality in North Sumatra Province, Indonesia.

Published as part of 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), pp. 1-55 in Zootaxa 4878 (1) on pages 41-43, DOI: 10.11646/zootaxa.4878.1.1, http://zenodo.org/record/4424570