Nidirana noadihing, Boruah & Deepak & Das, 2023

Boruah, Bitupan, Deepak, V. & Das, Abhijit, 2023, Musicians in the marsh: a new species of music frog (Anura: Ranidae: Nidirana) from Arunachal Pradesh, India, Zootaxa 5374 (1), pp. 51-73 : 56-68

Nidirana noadihing sp. nov.

urn:lsid:zoobank.org:act:619C0524-1B26-42E4-B9C3-5500DEE8BD55

Holotype ( Figures 3 and 4 ). WII-ADA1766 , an adult male collected from ~ 2.3 km southeast of Gandhigram village (27°15ˊ53.12˝ N and 96°56ˊ17.12˝ E, 1086 m elevation) and ~ 0.2 km east from the confluence of NoaDihing river and Yakhulo river, Changlang district, Arunachal Pradesh, India ( Figure 1 ) on 16 September 2022 by Abhijit Das, Bitupan Boruah and Naitik G. Patel.

Paratypes ( Figure 5 ). One adult male ( WII-ADA1765 ) and one adult female ( WII-ADA1789 ) were collected along with holotype from the same locality and same date . One adult female ( WII-ADA3154 ) and one adult male ( WII-ADA3156 ) collected from Gandhigram (27°16ˊ43.27˝ N, 96°53ˊ22.85˝ E, 1067 m elevation) ( Figure 1 ) on 17 September 2022 by Abhijit Das, Bitupan Boruah and Naitik G. Patel .

Referred materials. Two juveniles ( WII-ADA3003 , WII-ADA3004 ) collected from near Glaw lake , Kamlang Tiger Reserve (27°41ˊ45.66˝ N, 96°26ˊ44.42˝ E, 1202 m elevation) ( Figure 1 ) on 2 September 2022 by Abhijit Das, Bitupan Boruah and Naitik G. Patel . One juvenile ( WII-ADA3138 ) collected from Gandhigram (27°16ˊ09.36˝ N, 96°55ˊ51.53˝ E, 1063 m elevation) on 15 September 2022 Abhijit Das, Bitupan Boruah and Naitik G. Patel. Juvenile samples were excluded from the morphological description and comparison .

Diagnosis. Body robust with SVL 46.5–59.1 mm (n = 3) in adult males and SVL 60.6–66.0 mm (n = 2) in adult females. Snout rounded in dorsal view, longer than eye diameter. A pair of subgular vocal sacs and nuptial pad with fine granules in two patches on first finger present in adult males. Toe tips slightly dilated and oval, circum-marginal grooves present on all toes. Dorsal skin smooth with scattered small tubercles. A longitudinal maxillary ridge followed by a rictal gland present. Tympanum large, supratympanic fold absent. A large supra-brachial gland present behind the rictal gland in adult males. A pair of dorsolateral fold present on dorsum. A pale cream coloured mid dorsal line from the snout tip to the vent present. Hindlimbs with dark cross bars.

Description of the holotype. Body robust, SVL 59.1 mm. Head length longer than its width (HW/HL= 0.9). Snout rounded in dorsal view and obtuse in lateral view, protruding in ventral view. Snout length slightly larger than eye diameter (ED/SL= 0.93), nostril small, oval, obliquely oriented, laterally positioned, a rim surrounded posterior part of the nasal and a small tubercle ventrolaterally present at the posterior end. Nostril equidistant from the eye and snout tip (EN/NS= 0.97). Canthus rostralis smooth and rounded, loreal concave and oblique. Eyes moderately large (ED/HL= 0.36). Tongue cordiform, deeply notched behind. Choanae oval, vomerine teeth distinct in two oblique rows, anterior to choanae, closer to each other than choanae. A pair of subgular vocal sacs present and a pair slit like openings present at posterior of lower jaw. Inter upper eyelid width smaller than internarial distance (IUE/IN= 0.86) and larger than upper eyelid width (UEW/IUE= 0.92). inter upper eyelid space flat. Tympanum distinct, nearly rounded, relatively large (HTYD/ED= 0.62).

Forelimbs comparatively robust, FAL 0.2 of SVL and HAL 0.24 of SVL. First finger longer than second and fourth finger. Fourth finger is the shortest finger. Relative length of fingers IV<II<I<III. Finger tips rounded and slightly dilated. Circum-marginal grooves barely visible on third and fourth fingers only. Palmer tubercles distinct, inner one largest and oval, middle one rounded and outer one narrow and elongated. Supernumerary tubercles not visible except a single one on fourth finger is barely visible. Dermal fringe present only on second and third finger along inner lateral side. Nuptial pad with fine granules, in two patches on first finger, upper one at the level of subarticular tubercle covering ventrolateral to dorsal surface of the finger, lower nuptial pad near base of the palm from the outer margin of inner metacarpal tubercle to dorsal side of the hand. Webbing absent.

Hindlimbs robust, tibia length half of SVL (TBL/SVL= 0.5) and foot length more than half of SVL (FOL/SVL= 0.53). Thigh length slightly smaller than tibia length (TL/TBL= 0.99), foot length greater than thigh length and tibia length (TL/FOL= 0.94, TBL/FOL= 0.95), heels overlapping when hindlimbs flexed at right angles to axis of body. Relative length of the toes I<II<III<V<IV. Inner metatarsal tubercle narrow and elongated, outer one absent. Dermal fringe present on all toes on both sides. Toe tips slightly dilated and oval, circum-marginal grooves present on all toes, not meeting at the tips. Webbing moderate, I1–1 - II½–2III1–2 - IV2–1 + V.

Dorsal skin on head and upper eyelids smooth with scattered small tubercles, lateral side of the head smooth. A longitudinal maxillary ridge starting below nostril, running below the lower border of eyes and tympanum to mandibular region, posteriorly more prominent, followed by a rictal gland. A large supra-brachial gland present behind the rictal gland. Pineal ocellus indistinct. Anterior dorsum smooth and numerus small tubercles present, posterior dorsum with more prominent and densely placed tubercles, Flank smooth with scattered small tubercles. A pair of dorsolateral fold starting from posterior end of the upper eyelids to above the groin. Supratympanic fold absent. Dorsally forelimbs smooth, a few small tubercles scattered, indistinct longitudinal ridges present on lower arm. Thigh, tibia, tarsus dorsally smooth, distinct tubercles on it, thin longitudinal ridges present on tibia. Ventral skin on throat, chest and belly smooth, skin on ventral side of thigh smooth, granular at the rear end, a few large tubercles scattered above and below the vent. Ventrally tibia smooth, small tubercles spread over tarsus.

Colouration in life ( Figure 3 ). Dorsally snout, head and back is light brown, a pale cream coloured mid dorsal line from the snout tip to the vent which is not prominent on snout as posterior dorsum, edges irregular. Edges of the mid dorsal line slightly dark brown. A few small, irregular shaped and sized spots on upper eyelids and anterior dorsum. Posterior dorsum with dark olive coloured patches of irregular shape and size.A dark brown stripe starting in front of nostril, covering the loreal region through lower border of the eyes to the space between eye and tympanum. Longitudinal fold on upper jaw and the rictal glands golden yellow. Eye pupil surrounded by a golden rim, iris dark brown with golden spackle over it. Tympanum light brown with pinkish tinge, centre pale yellowish. Flank paler than dorsum with numerous dark olive patches of irregular shape and size, starting behind the tympanum to groin below the dorsolateral folds. Light yellow and dark olive patches on suprabrachial gland. Forelimbs light brown with dark olive patches which are dense on lateral sides, no complete cross bars. Dorsally hindlimbs light brown with dark olive cross bars on thigh, tibia, tarsus and base of foot. Six cross bars on each thigh of which outer two are incomplete or broken. Four cross bars on each tibia, and two other pair of cross bars towards the heel but those are disjunct by large gap dorsally. Three cross bars on each tarsus followed by two pairs of incomplete cross bars. Two cross bars on the base of foot present. Groin and outer lateral surface of thighs pale yellow with irregular dark olive patches. Ventrally throat, forelimbs, thighs and tibia pale brown with pinkish tinge, chest and belly cream coloured with golden tinge.

Colouration in preservative ( Figure 4 ). Snout, dorsum, flank and limbs light greyish brown, markings and cross bars dark brown. Ventrally off-white with light brown mottling on throat, on lower jaw it is denser. Palms and foot including webbing are with dense brown mottling. Dark brown patches on ventral side of the forearms.

Sexual dimorphism. Males have a pair of subgular vocal sacs and a pair of internal slits like openings at the rear of jaw. A large suprabrachial gland present in males ( Figure 3 D ) and absent in females. Two separate patches of nuptial pad present on first finger in males ( Figure 4 G ). In female nostril closer to the eyes than snout tip.

Morphological variation. Measurements of the type series are given in the Table 2 . Markings on dorsum, flank, limbs and number of cross bars on limbs are variable among the individuals. Pineal ocellus not visible in WII-ADA1765, WII-ADA1789 and WII-ADA3156; barely visible in WII-ADA3154, circum-marginal grooves on fingers are not visible in WII-ADA1765, supernumerary tubercles are not visible in WII-ADA1765, WII-ADA1789 and WII-ADA3154, single supernumerary tubercle on each first and fourth finger of WII-ADA3156 are barely visible. Dark brown blotches on flank and thighs of the paratypes are not dense compared to the holotype. Number of cross bars on thigh and tibia varies (3–4) among the paratypes.

TABLE 2. (Continued)

Morphological comparison. Detail comparison among the extant species of Nidirana and the new species is provided in Table 5. The new species differs from N. chapaensis (Bourret, 1937) , N. chongqingensis Ma and Wang, 2023 , N. daunchina (Chang, 1933) , N. guangxiensis Mo, Lyu, Huang, Liao, and Wang, 2021 , N. hainanensis (Fei, Ye, and Jiang, 2007) , N. nankunensis Lyu, Zeng, Wang, Lin, Liu, and Wang, 2017 , N. okinavana ( Boettger, 1895) , N. yaoica Lyu, Mo, Wan, Li, Pang, and Wang, 2019 , N. yeae Wei, Li, Liu, Cheng, Xu, and Wang, 2020 by larger body size in adult males, SVL= 46.5–59.1 mm, and adult females, SVL= 60.6–66.0 mm (vs. SVL= 36.8–44.2 mm in adult males and 41.0– 51.8 mm in adult females of N. chapaensis, SVL = 41.8–43.3 mm in adult males of N. chongqingensis, SVL = 44.0–53.0 mm in adult males of N. daunchina, SVL = 49.9–51.0 mm in adult females of N. guangxiensis, SVL = 32.8–44.4 mm in adult males of N. hainanensis, SVL = 33.3–37.1 mm in adult males and SVL= 37.8–39.5 mm in adult females of N. nankunensis, SVL = 35.5–42.8 mm in adult males and SVL= 44.6–48.8 mm in adult females of N. okinavana, SVL = 40.4–45.9 mm in adult males of N. yaoica , 41.2–43.5 mm in adult males of N. yeae ).

Further, the new species differs from N. chapaensis by presence of tubercles on dorsum (vs. absent or few above vent); from N. hainanensis by presence of nuptial pads on first finger (vs. nuptial pad absent), presence of tubercles on dorsum (vs. absent); from N. adenopleura ( Boulenger 1909) , N. chongqingensis , N. daunchina , N. guangdongensis Lyu, Wan, and Wang, 2020 , N. guangxiensis , N. guibeiensis Chen, Ye, Peng, and Li, 2022 , N. mangveni Lyu, Qi , and Y.-y. Wang, 2020, N. nankunensis , N. occidentalis Lyu, Wan, and Wang, 2020 , N. pleuraden ( Boulenger, 1904) and N. xiangica Lyu and Wang, 2020 by presence two nuptial pads on first finger (vs. single nuptial pad on first finger), presence of tubercles on dorsum (vs. absent or few above vent); from N. okinavana by presence two nuptial pads on first finger (vs. single nuptial pad on first finger), presence of tubercles on dorsum (vs. absent), subgular vocal sacs present in males (vs. absent); from N. yaoica and N. yeae by presence two nuptial pads on first finger (vs. single nuptial pad on first finger), presence of tubercles on dorsum (vs. absent).

The new species differs from N. chongqingensis , N. daunchina , N. guangxiensis , N. leishanensis Li, Wei, Xu, Cui, Fei, Jiang, Liu, and Wang, 2019 by presence of tubercles on dorsum (vs. absent); differs from guibeiensis by heels overlapping when thighs are held at right angle to body (vs. heels not overlapping), presence of tubercles on dorsum (vs. present on posterior dorsum); differs from N. leishanensis by presence of two nuptial pads on first finger (vs. nuptial pad present on first and second finger); differs from N. occidentalis and N. pleuraden by presence of circum-marginal grooves on toes (vs. absent), tubercles present on anterior to posterior dorsum (vs. tubercles or spinules present only on posterior dorsum), from N. shiwandashanensis Chen, Peng, Li and Liu, 2022 by presence of tubercles on dorsum (vs. absent), heels overlapping (vs. not overlapping).

The new species is morphologically close to N. lini ( Chou, 1999) , however it differs by the presence of circum-marginal groove only on third and fourth finger (vs. present on all fingers), outer metatarsal tubercle absent (vs. small and round outer metatarsal tubercle present), spinules scattered on whole dorsum (vs. spinules present on posterior half of dorsum).

TABLE 3. (Continued)

Acoustics. Advertisement call of Nidirana noadihing sp. nov. consists of 2–3 notes. First note is (Type I) different from the later ones (Type II) in structure and temporal parameter ( Figure 6 ). The first note (Type I) is followed by one or two Type II notes. Notes are amplitude modulated. At an ambient temperature 24.5º C call duration ranged from 0.58– 0.92 s (0.67 ± 0.13 s, n = 10) with an inter call interval of 20.87– 38.72 s (27.64 ± 5.78 s, n = 9). Duration of note Type I is relatively shorter than that of note Type II. The duration of Type I notes varied between 0.15– 0.19 s (0.17 ± 0.01 s, n = 10) and duration of Type II notes varied between 0.2– 0.29 s (0.26 ± 0.03 s, n = 12). Inter note interval ranged from 0.13– 0.28 s (0.16 ± 0.04 s, n = 12). Dominant frequency of the calls was 473.7 Hz (n = 10).

Acoustic comparisons. The call of Nidirana noadihing sp. nov. differs from that of congeners by having 2–3 notes and first note different from the latter notes vs. call containing 2–5 identical regular notes in N. adenopleura , 3 notes in N. chapaensis , 2–5 notes with a specific first note in N. daunchina , 6–11 identical regular notes in N. guangxiensis , 2–4 identical regular notes in N. guangdongensis , two identical regular notes in N. hainanensis , single note in N. leishanensis , 2–7 identical regular notes in N. mangveni , 5–7 identical regular notes in N. lini , 10–25 fast-repeated regular notes in N. okinavana , 13–15 fast-repeated notes in N. nankunensis , 5–7 identical regular notes in N. pleuraden , two identical regular notes in N. shiwandashanensis , 1–3 rapidly repeated, identical, regular notes in N. yaoica .

Further calls of the new species differ from that of its congeners by call duration 0.58– 0.92 s (vs. 4.45– 11.98 s in N. guangdongensis , 1.01– 1.92 s in N. guangxiensis , 1.55– 7.77 s in N. guibeiensis , 4.24– 17.23 s in N. mangveni , 3.32– 6.25 s in N. xiangica ), inter note interval of 0.13– 0.28 s (vs. 1.04– 2.45 s in N. adenopleura , 0.8– 2.63 s in N. guangdongensis , 0.7– 1.83 s in N. guangxiensis , 1.25– 2.21 s in N. guibeiensis , 0.59– 1.93 s in N. mangveni , 0.85– 1.95 s in N. xiangica ), duration of note Type I 0.15– 0.19 s (vs. 1.53– 2.32 s in N. guibeiensis , 1.48– 2.33 s in N. xiangica ), duration of note Type II 0.2– 0.29 s (vs. 0.71– 0.93 s in N. guibeiensis , 6.01– 1.28 s in N. xiangica ).

Dominant frequency of the calls of Nidirana noadihing sp. nov. is 473.7 Hz (vs. 1894.9 Hz in N. guangxiensis , 516.8 Hz in N. yaoica ).

Etymology. We name this species after Noa-Dihing river of Arunachal Pradesh, India. The type locality of the new species lies at the catchment of Noa-Dihing river. The specific epithet “ noadihing ” is a noun in apposition.

Suggested common name. Noa-Dihing Music Frog.

Natural history and geographical distribution. We encountered adult males and females of Nidirana noadihing sp. nov. in a marshy area ~ 0.2–0.5 km from of Noa-Dihing river at night between 15 and 17 September, 2022. The marshy habitat is dominated by the Rotala sp. and surrounded by forested habitat of various degradation state. Males were calling from circular shallow water filled pits among the Rotala vegetation ( Figure 7 B ). Calling males and the females of the species were recorded among the marshy areas near crop lands. Individuals were calling from forest edges of a newly constructed fish pond near Gandhigram Village. We recorded the juveniles along newly constructed roadside between Gandhigram and Vijayanagar on 15 September, 2022. On roadside, we observed one juvenile with skin lesion on dorsum. In Kamlang Tiger Reserve, we heard distinctive calling of the species from the marshy edges of Glaw lake both night in day time. Juveniles were recorded along stream near Glaw lake between 2 September and 3 September, 2022. Juvenile individuals were also recorded among wet grasses near wallowing pools of domestic buffaloes close to Noa-Dihing river. Other sympatric anuran species present in the habitat with Nidirana noadihing sp. nov. were Minervarya sp. at Gandhigram and Xenophrys sp. , Rhacophorus cf. suffry , Amolops sp. at Kamlang Tiger Reserve. Currently the new species was only recorded from Kamlnag Tiger Reserve around Glaw lake at an elevation 1202 m a.s.l. and at Gandhigram at an elevation 1063–1086 m a.s.l. ( Figure 1 ).

Figures

FIGURE 1. Map showing the type localities of Nidirana species. 1. Nidirana noadihing sp. nov., 2. referred material locality of N. noadihing sp. nov., 3. N. occidentalis, 4. N. daunchina, 5. N. pleuraden, 6. N. lini, 7. N. chapaensis, 8. N. yeae, 9. N. chongqingensis, 10. N. leishanensis, 11. N. guanxiensis, 12. N. shiwandashanensis, 13. N. guibeiensis, 14. N. yaoica, 15. N. hainanensis, 16. N. xiangica, 17. N. guangdongensis, 18. N. nankunensis, 19. N. mangveni, 20. N. adenopleura, 21. N. okinavana. Insert map: 1. Gandhigram, 2. Glaw lake, Kamlang Tiger Reserve. Inset image: Nidirana noadihing sp. nov..

FIGURE 3. Holotype (WII-ADA1766) of Nidirana noadihing sp. nov. in life. A. dorsal view of full body, B. ventral view of full body, C, D. dorsolateral view of left and right side respectively, inset image showing rictal gland (rg) and suprabrachial gland (sbg), E. groin, F. showing vent and outer lateral side of thighs.

FIGURE 4. Holotype of Nidirana noadihing sp. nov. (WII-ADA1766) in preserved condition. A. dorsal view, B. ventral view, C. right side lateral view of the head, D. left side lateral view of the head, E. ventral view of palm, F. ventral view of feet, G. showing the nuptial pads on first finger marked with yellow arrow. Scale bar= 10 mm.

FIGURE 5. Paratypes of Nidirana noadihing sp. nov. Dorsal view on left and ventral view on right. A, B. WII-ADA1789; C, D. WII-ADA3154, E, F. WII-ADA1765. Scale bar= 10 mm.

FIGURE 6. Advertisement call of Nidirana noadihing sp. nov. (holotype, WII-ADA1766). A. call with two notes, B. call with three notes. 1. Oscillograms, 2. Spectrograms.

FIGURE 7. Habitats of Nidirana noadihing sp. nov. at Gandhigram. A. Landscape view of the Noa-Dihing river basin where the population of the new species was discovered. B. Microhabitat of Nidirana noadihing sp. nov. Water filled pits where calling males were observed are indicated with yellow arrows.