Raorchestes mindat Köhler et al., 2025

Boruah, Bitupan, Deepak, V. & Das, Abhijit, 2025, Revision of bush frogs, Raorchestes and Philautus (Amphibia: Anura: Rhacophoridae) from the northeast Indian biodiversity hotspot with description of thirteen new species, Vertebrate Zoology 75, pp. 517-625 : 517-625

Raorchestes mindat Köhler et al., 2025

Figure 43; Tables 1, 2, S 12

Materials examined.

Three adult males ( WII-ADA 883 , WII-ADA 885 , WII-ADA 887 ) collected by BB and AD on 5 August 2021 from Fakim ( 25.80594°N, 94.97698°E, elevation 1940 m a. s. l.), Kiphire District, Nagaland, India .

Comments on taxonomic status.

Raorchestes mindat was recently described by Köhler et al. (2025) from Myanmar. With the following morphological exception, our three specimens from Nagaland we referred to R. mindat with support of molecular data (Figs 2 , 3 ). In the original description, tibia length is greater than thigh length (vs. tibia length smaller than thigh length in our collected specimens); tongue rounded, not notched (vs. tongue posteriorly notched in our specimens). Additionally, life colouration of the species was not provided in the original description as it was based on 20 years old specimens ( Köhler et al. 2025). Below we provided morphological description, life colouration, and variations of the species based on newly collected specimens.

Description of a freshy collected male ( WII-ADA 885 ).

An adult male (Fig. 43 A – E ) with vocal sac, SVL 17.9 mm; head slightly wider than its length ( HL / HW = 0.92); snout rounded in dorsal view and sub ovoid in ventral view, truncated in lateral view, slightly projected beyond the lower jaw, a bluntly conical projection on snout tip; snout length nearly equal to eye length ( SL / EL = 0.92) and equal to inter-upper eyelid width; nostril oval in shape, oblique and laterally positioned, equidistant from snout tip and eyes; internarial distance smaller than inter-upper eyelid width ( IN / IUE = 0.79) and greater than upper eyelid width ( UEW / IN = 0.84); inter upper eyelid space slightly convex; canthus rostralis smooth, slightly oblique; loreal region concave; tympanum round, indistinct, less than one third of eye length ( HTYD / EL = 0.28); eye moderate in size, less than half of head length ( EL / HL = 0.41).

Forelimbs slender, forearm length equal to hand length, nearly one third of snout-vent length ( FAL / SVL = 0.27); third finger longest, relative length of fingers = I <II <IV <III; fingers with rounded disc; circum-marginal groove present on each disc; disc on third finger widest and greater than the tympanic diameter ( HTYD / FID = 0.78); webbing absent between fingers; subarticular tubercles distinct, proximal one on finger III and IV smaller in size than that of upper one; supernumerary tubercles absent; palmar tubercles indistinct.

Hindlimbs slender; thigh longer than tibia ( TBL / TL = 0.94) and foot ( FOL / TL = 0.8); tibia longer than foot ( FOL / TBL = 0.85); fourth toe longest, relative length of toes = I <II <III <V <IV, toes with rounded disc; circum-marginal groove present on each disc; disc on fourth toe wider than tympanic diameter and slightly smaller than that of finger III; subarticular tubercles distinct, rounded, proximal one on toe IV very small; supernumerary tubercles absent; inner metatarsal tubercle present, outer metatarsal tubercle absent.

Skin on dorsal aspect of head and dorsum smooth; distinct and bluntly conical tubercles on upper eyelid, posterior part of head, posterior to upper eyelid and anterior part of dorsum; lateral aspect of head smooth, few rounded tubercles behind angle of jaw; supratympanic folds distinct; dorsum with dense spinules, spreading towards flank; forelimbs and hindlimbs smooth with indistinct tubercular projections; on ventrum, head smooth, abdomen, ventral aspect of lower arm, and thigh distinctly granular; numerous flat granules on palm and ventral aspect of foot.

Colouration in life.

Dorsally head, dorsum and limb dark brown, flank slightly paler; enlarged black patch between two white patches present on groin, covering posterior half of the flank; similar black and white patches of irregular size and shape present on lateral and ventral aspects of thigh, tibia, and lateral aspect of tarsus; one broad black or dark brown crossbar present on dorsal side of each forearm, thigh and tibia; irregular small pale bluish white spots on upper jaw present; ventrally dark brown; small irregular pale-bluish white spots present on gular region, forearm and hind arm, chest, abdomen and ventral side of tarsus; digital disc yellowish on dorsal aspect.

Colouration in preservative.

Dorsal aspect of head and dorsum similar to that of life colouration; dorsal aspect of limbs slightly paler brown than in life; ventral aspect pale brown, all white and black markings visible as when it was alive.

Morphological variation.

Details of morphometric variations are provided in Table S 12. Shape and size of the black and white patches on groin and hindlimbs varies among individuals; intensity of the small white spots on the ventral aspect of body and on chin varies among individuals of this species.

Phylogenetic relationship.

Raorchestes mindat is sister to a group containing R. huanglianshan and R. menglaensis with weak support in ML analysis (Fig. 2 ). In BI analysis, R. mindat recovered as a sister to R. annandalii with weak support (Fig. 3 ). The genetic divergence of R. mindat with its congeners included in this study are 2.4–7.4 % in the 16 S, 11.7–17.7 % in the cyt b genes (Table S 7 A – B).

Distribution and natural history.

Raorchestes mindat was known only from the type locality, between Hline Thoat village and Gyin Dwe village, Ovatmataung National Park of Mindat District, Myanmar. The present study reports this species from India for the first time (Fig. 19 B ) and it extends the northeast distribution boundary of the species by 548 km from the type locality in Myanmar. We recorded calling males in a degraded agricultural farm on the edge of Fakim Wildlife Sanctuary (Fig. 44 A ). Calling individuals were found on the hill slopes of an abandoned jhum field between 18: 00–19: 00 hrs on leaves of Eupatorium sp. , one metre above ground. The area was mostly covered in maize and soybean as well as invasive plants such as Eupatorium sp. and Parthenium sp. , on a slope with an incline of approximately 60 degrees.

Figures

Figure 2. A, B Maximum likelihood tree inferred from the concatenated data set (16 S, cyt b, COI and RHO) for Raorchestes species from northeast India, Indo-Burma and Indo-China. Outgroups are not shown in this tree. Numbers at the internal branches represent ultrafast bootstrap values (UFB). Values below 50 are not shown. Scale bar: substitutions per site.

Figure 3. A, B Bayesian tree inferred from the concatenated data set (16 S, cyt b, COI and RHO) for Raorchestes species from northeast India, Indo-Burma and Indochina. Outgroups are not shown in the tree. Numbers at the nodes represent posterior probability (PP) value. Values <0.5 are not shown. Scale bar: substitutions per site.

Figure 19. Distribution of Raorchestes species in northeast India. A Raorchestes garo and three others closely related new species; B Raorchestes kempiae, R. shillongensis, R. mindat and three new species. Type localities are denoted with stars.

Figure 43. Raorchestes mindat A – E WII-ADA 885 in preserved condition, A dorsal view, B ventral view, C lateral view of head, D v entral view of left feet, E ventral view of left hand. F, G WII-ADA 883 in preserved condition, F dorsal view, G ventral view. H – K WII-ADA 885 in life, H dorsolateral view, I ventral view, J lateral view showing groin, K posterior view of thigh. Inset image showing dorsal spinules on dorsum in F and granular skin on abdomen in I. Scale bar = 10 mm.

Figure 44. Habitats of Raorchestes mindat and R. annandalii A Landscape view of the hills at Fakim WLS and B landscape view at Darjeeling.