Nyctibatrachus dattatreyaensis, Bhatta, Gopalakrishna, 2008

Bhatta, Gopalakrishna, 2008, A new species of Nyctibatrachus Boulenger (Amphibia: Anura: Nyctibatrachidae) from the surroundings of Bhadra Wildlife Sanctuary, Western Ghats, India, Zootaxa 1914, pp. 45-56 : 46-54

Nyctibatrachus dattatreyaensis sp. nov.

( Figures 1 , 2 , 3 & 4 ; Table 1 )

Holotype: an adult male, 40.0 mm SVL, ZSI/ WGFRS /V/A/ 646 (Zoological Survey of India, Western Ghats Field Research Station, Calicut), collected on 27th December 2006 at 19.00 hours by Dinesh, K.P. and M.L. Dilip Kumar along a slow flowing rivulet upstream of Manikyadhara falls (13 0 25’ N latitude; 75 0 46’ E longitude; altitude approx 1515 m above sea level), Dattatreya Peeta, Bhadra Wildlife Sanctuary, Chickmagalur district, Karnataka state, Southwestern India.

Paratypes: Two females (ZSI/ WGFRS /V/A/647, 648) and one male (ZSI/ WGFRS /V/A/649) collected on 9th November 2006 by K.G. Emiliyamma and party from the type locality; two males (ZSI/ WGFRS /V/A/650, 651), collection data same as holotype.

Diagnosis: The new species is assigned to Nyctibatrachus due to the combination of following set of characters; contracted pupil rhomboidal; dorsum with fine set of folds; habitus short and squat; omosternum forked at base; vomerine teeth present; median lingual process absent; femoral glands present and widened finger and toe tips.

N. dattatreyaensis sp. nov. can easily be distinguished from all other species in the genus by the following combination of characters: head wider than long, snout slightly projecting beyond mouth; whole of dorsum corrugated with several transverse folds, the anterior three folds very prominent and with a longitudinal dorsolateral fold on either side; lateral part of the body with two longitudinal folds; a well defined supratympanic fold from posterior corner of eye to shoulder; a small fold from eye to the posterior corner of mouth commissure; fingers and toes with disks, circummarginal grooves restricted to toe discs; webbing on toes medium (3/ 4th); femoral glands and thumb pad very prominent in adult males; body, colored reddish-brown to blackishbrown dorsally with two yellowish dorsolateral bands and pale ventrally.

Description of the holotype: Some morphometric data are given in Table 1 . The holotype is in good condition.

A medium sized species of Nyctibatrachus (SVL 40.0 mm); body mode compact and squat; head wider (HW 15.2 mm) than long (HL 12.2 mm; MN 10.2 mm; MFE 8.2 mm; MBE 4.2 mm), convex; snout slightly pointed (SL 7.0 mm), marginally protruding, its length longer than horizontal diameter of eye (EL 5.0 mm); canthus rostralis rounded; loreal region concave; interorbital space flat (IO 4.0 mm) and double the upper eyelid width (UEW 2.0 mm); maximum distance between the upper lids larger (IUE 9.2 mm), three times more than the internarial distance (IN 3.0 mm); distance between back of eyes (IBE 14.0 mm) is more than double the distance between front of eyes (IFE 6.0 mm); nostrils oval, without a flap of skin, nearer to eye (EN 2.8 mm) than to snout tip (NS 3.8 mm); eyes large (EL/HL= 0.40) protruding upside the head, its diameter more than eye to nostril distance (EL/EN=1.7); pupil rhomboidal black; tympanum indistinct; pineal ocellus absent; vomerine ridge present posterior to choanae bearing 3 sharp spinose teeth randomly on each ridge, ridges are close to each other than to choanae; symphysial knob ‘W’ shaped very prominent; tongue moderate, oval slightly emarginated, median lingual process absent; parotoid glands, cephalic ridges and co-ossified skin absent.

Forelimbs (FLL 9.2 mm) strong and equal to hand (HAL 9.2 mm) length; Fingers thin, long, rounded (TFL 4.8 mm) without any dermal fringes and webbing absent; relative length of fingers, shortest to longest: I<II<IV<III; tips of fingers enlarged with disk, circum marginal groove absent, dorsal longitudinal groove present on all the finger disks; subarticular tubercles moderate, round, minute one each on finger I and II and two each on finger III and IV; prepollex and palmar tubercle indistinct.

Parameters 646* 647# 650# 651# mean ± standard devia- 648# 649# mean ± standard devia-

tion (range) tion (range)

Sex Male Male Male Male Female Female

* Holotype; # Paratypes

Hindlimbs moderately long; tibia length (TL 18.8 mm) more than two times longer than wide (TW 6.8 mm), longer than thigh length (FL 17.6 mm) and sub equal to the distance from base of inner metatarsal tubercle to tip of toe IV (FOL 18.2 mm); heels separate widely when the tibia are bent right angles to the body; toes thin and long; toe IV long (FTL 10.4 mm) more than double the distance from base of tarsus to tip of toe IV (TFOL 25.0 mm); relative length of toes, shortest to longest: I<II<V<III<IV; tips of toes with enlarged disks, disks with circummarginal grooves; webbing medium(3/4th) (I 0- 1 II 0- 1 III 0- 1 IV 1-0 V) ( Fig. 4 b) (MTTF 11.2 mm; MTFF 11.8 mm; TFTF 5.8 mm; FFTF 5.4 mm); dermal fringe along toe V distinct; subarticular tubercles simple, moderate, oval all present; inner metatarsal tubercle short prominent, spade shaped; its length (IMT 3.2 mm) subequal to length of toe I (ITL 3.4 mm); inner tarsal ridge present; outer metatarsal tubercle, supernumerary tubercles and tarsal tubercles absent.

Male secondary sexual characters: In life males have transparent vocal sacs in front of shoulders; a nuptial pad covering the entire dorsal surface of the first finger ( Fig 4 a) and a pair of much raised glandular femoral glands which are two times more in length (FGL 7.6 mm) than width (FGW 3.4 mm), (is conspicuous both in life and preservative).

General skin fold pattern: Skin is highly corrugated on the dorsal and lateral surfaces of the body, forelimbs and hind limbs with short longitudinal folds; snout with a ‘Y’ shaped fold from middle of upper lip, its arms bifurcating in-between the nares and running towards the orbit; eye lids finely vermiculated with short longitudinal folds; a horizontal fold of 3.0 mm at the interorbital space at the anterior corner of the eyes; a second horizontal fold of 6.0 mm at the posterior corner of the orbit 4.0 mm away from the former and a third horizontal fold of 7.0 mm on the dorsum above the shoulder 7.0 mm behind the second; supratympanic fold and a fold from posterior corner of eye to mouth commissure distinct; either side of the dorsum with a dorsolateral fold, lateral part of the body with two more lateral folds, together appearing as 3 parallel folds when viewed from the lateral angle ( Fig 1 ); tarsus with few small pigmented spine like warts. Throat with dense glandular longitudinal folds and rest of the venter soft glandular without any folds; belly smooth; lower lip dotted with a single row of small discontinuous glandular folds; thigh ventrally smooth.

Colour in preservative ( Fig 2 a, 2b): The dorsal and lateral parts of the body mottled with rocky black and cream color, with a pair of white dorsolateral lines from the orbit of eye to the region of vent running paralelly with the lateral folds; a short white band from the middle of the dorsum to vent in between the two white dorsolateral bands; on the loreal region white spots just in front of eyes to the region of upper lip; white horizontal band between the eyes; a white line from the upper lip to inter-nostril space; white patch at the region of tympanum; upper lip barred; femoral glands cream white; dorsal parts of limbs: forelimbs, thigh, shank and foot up to the tip of fingers and toes barred with rocky black cross bars; throat pale brown; lower lip dotted with white spots; chest, belly and thigh whitish, soft; undersurface of forelimbs mottled with brown; hind limbs speckled with brown; femoral glands granular, white in color ( Fig 2 b).

Colour in life ( Fig 1 ): Iris golden yellow in its upper part, pupil rhomboidal, black in color. Sides of head mottled with blackish brown, lighter in tympanic region. A yellow horizontal band connecting the anterior corner of eye, a yellow line at the region of canthus rostralis starting from the tip of the upper lip and continuing on with the dorsolateral band breaking at the region of orbit. Mid-dorsum reddish black or stone black; arm mottled with blackish brown; a light yellow nuptial pad on the first finger of the male; hind legs barred; sides of the body yellow mottled with a network of folds bearing white spots on the raised edges of the folds. Throat translucent with brown glandular spots. Chest, belly and anterior part of thighs translucent, where internal organs can be clearly seen. Posterior part of thigh with raised glossy light yellow femoral gland in males.

Etymology: The specific epithet is derived from the divinity, Lord “Dattatreya”, a shrine, worshiped by people at Dattatreya Peeta, the type locality of the species under description here.

Additional information from paratypes and variations: Morphological data are given in Table 1 . Paratypes range from 36.2 mm to 41.0 mm in SVL; in all the external morphological characters they are similar to holotype. All the smaller young ones observed with SVL 20.0 mm to 22.0 mm in the field possess all the above mentioned skin fold patterns, even the young ones of this species can be identified on field just by the dorsal fold patterns and the two white dorsolateral bands.

Ecological notes: The paratypes were collected between 13.30 to 14.30 hrs in the slow moving stream of Manikyadhara falls in the hill ranges of Dattatreya Peeta. Day time activity was found to be less when compared to the evening and night time activity between 19.00 hrs to 22.00 hrs during the collection of holotype. At day time, specimens were located by turning the small boulders upside down and locating them in water was finding difficult because of their reddish brown dorsum camouflaging with the ferruginous substratum. The hill ranges at type locality was historically known as ‘Chandra Drona Parvatha’ and this species is expected to found along this hill ranges. As nothing is known of its biology; we recommend the conservation status currently should be considered as data deficient.

Comparisons: We compared N. dattatreyaensis sp. nov. with all the valid 15 species of Nyctibatrachus based on the original descriptions and examination of available types. The possession of three prominent transverse folds on the anterior dorsum - a dorsolateral fold and two lateral folds as well as the highly corrugated skin is unique to N. dattatreyaensis in this group. In addition to the fold patterns N. dattatreyaensis sp. nov differs from, N. beddomii (Boulenger) (up to 15.6 mm SVL); N. kempholeyensis (Rao) (up to 18.0 mm SVL); N. anamallaiensis (Myers) (up to 15.7 mm SVL); N. minor Inger, Shaffer, Koshy and Bakde (up to 21.5 mm SVL); N. deccanensis Dubois (up to 23.1 mm SVL); N. sholai Radhakrishnan, Dinesh and Ravichandran (up to 22.1 mm SVL) and N. minimus Biju, Bocxlaer, Giri, Roelants, Nagaraju and Bossuyt (up to 14.9 mm SVL) in having large adult size (up to 41.0 mm SVL) at sexual maturity.

For the other medium to large sized (33.0 mm to 84.0 mm SVL) congeners we compare the new species, listing only diagnostic characters of the respective species.

N. humayuni Bhaduri and Kripalani , adult size up to 48.0 mm SVL (adult size up to 41.0 mm in N. dattatreyaensis ); dorsum with very small vermiculated folds (Fig 5a, b & c) (dorsum corrugated with three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); nostrils midway between the snout tip and anterior corner of eyes (nostrils nearer to orbit than to snout tip in N. dattatreyaensis ); vomerine patches with 6-8 teeth (vomerine ridge with 3 sharp spinose teeth in N. dattatreyaensis ); snout nearly equal to diameter of the eye (SL/EL=1.18) (snout length more than eye diameter (SL/EL=1.40) in N. dattatreyaensis ); tips of fingers and toes very well dilated in to disks with circummarginal groves (fingers and toes with disks but not well dilated in N. dattatreyaensis ).

N. petraeus Das and Kunte , adult size up to 43.2 mm SVL (adult size up to 41.0 mm in N. dattatreyaensis ); skin with close set of folds without any specific pattern (Fig 6a, b & c) (skin corrugated with distinct pattern of three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); body with a relatively narrow waist (width behind shoulders and at waist sub equal in N. dattatreyaensis ); finger and toe tips with well developed disks with circummarginal grooves (finger and toe disks not well developed only toe disks with circummarginal grooves in N. dattatreyaensis ).

N. karnatakaensis Dinesh, Radhakrishnan, Reddy and Gururaja , adult size up to 84.0 mm, largest species of the genus (adult size up to 41.0 mm in N. dattatreyaensis ); skin highly vermiculated with close set of glandular folds, no specific pattern (Fig 7a, b & c) (skin folds corrugated but not glandular, but with a distinct pattern of three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); subarticular tubercles on toes distinct and oval (subarticular tubercles on toes simple, moderate and oval in N. dattatreyaensis ).

N. major Boulenger , adult size up to 36.0 mm SVL (adult size up to 41.0 mm SVL in N. dattatreyaensis ); dorsum corrugated with numerous short irregular folds without any uniform pattern in adults, juveniles with less corrugations ( Fig 8 a & c). (dorsum with short irregular corrugations, with distinct three transverse folds, a dorsolateral fold and two lateral folds in adults, juveniles with distinct fold pattern in N. dattatreyaensis ); throat marbled with brownish grey or sepia ( Fig 8 b) (throat creamish white without any marblings in N. dattatreyaensis ); snout rounded (snout slightly pointed in N. dattatreyaensis ); web formula I 1- 2 II 1-2½ III 1-2 ½ IV 2 ½- 1 V (web formula I 0- 1 II 0- 1 III 0- 1 IV 1-0 V in N. dattatreyaensis ).

N. sylvaticus Rao , adult size up to 42.0 mm SVL (adult size up to 41.0 mm SVL in N. dattatreyaensis ); skin on the dorsum with tubercles and short glandular folds (dorsum with short irregular corrugations with, distinct three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); head as long as broad or slightly longer (head wider than long in N. dattatreyaensis ); snout not longer than diameter of eye (snout longer than diameter of eye in N. dattatreyaensis ); canthus rostralis angular, well marked (canthus rostralis rounded in N. dattatreyaensis ).

N. sanctipalustris Rao , adult size up to 39.0 mm SVL (adult size up to 41.0 mm SVL in N. dattatreyaensis ); skin nearly smooth in the young but covered by short semicircular folds on the back and the sides, in the adult (skin corrugated in the young ones with distinct folds and adults with three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); canthus rostralis absent (canthus rostralis rounded in N. dattatreyaensis ); snout length equals to diameter of eye (snout length more than the diameter of the eye in N. dattatreyaensis ); nostrils equidistant between eye and tip of snout (nostrils nearer to eye in N. dattatreyaensis ).

N. aliciae Inger, Shaffer, Koshy and Bakde , adult size up to 33.5 mm SVL (adult size up to 41.0 mm in N. dattatreyaensis ); dorsum with irregular series of short ridges ( Fig 9 a & c) (dorsum corrugated with folds with distinct three transverse folds, a dorsolateral fold and two lateral folds in N. dattatreyaensis ); snout rounded, canthus rostralis absent (snout slightly pointed, canthus rostralis rounded in N. dattatreyaensis ); finger and toe disks with circummarginal grooves (only toe disks with circummarginal grooves in N. dattatreyaensis ); femoral glands weak ( Fig 9 b) (femoral gland distinct in N. dattatreyaensis ).

N. vasanthi Ravichandran , adult size up to 39.0 mm SVL (adult size up to 41.0 mm SVL in N. dattatreyaensis ); dorsum in the mid-dorsal region from eye to groin without wrinkles, skin of belly and throat smooth ( Fig 10 a, b & c). (dorsum corrugated with distinct pattern of folds, skin on throat with glandular longitudinal folds in N. dattatreyaensis ); snout length nearly as long as the diameter of the eye (snout length more than the diameter of the eye in N. dattatreyaensis ); canthus rostralis indistinct (canthus rostralis rounded in N. dattatreyaensis ); tibia relatively long (TL/SVL=0.50 to 0.81) (tibia relatively short (TL/SVL=0.46 to 0.49) in N. dattatreyaensis ).

Figures

FIGURE 2. Dorsal (2 a) and ventral (2 b) view of holotype of N. dattatreyaensis sp. nov. (ZSI / WGFRS / V / A / 646). Scale bar = 10 mm.

FIGURE 3. Lateral view of holotype of N. dattatreyaensis sp. nov. (ZSI / WGFRS / V / A / 646). DTF (1 - 3), dorsal transverse folds; DLF (1 - 3), dorsal lateral folds.

FIGURE 8. Dorsal (a), ventral (b) and lateral (c) view of N. major (SVL = 37.4 mm).

FIGURE 9. Dorsal (a), ventral (b) and lateral (c) view of N. aliciae (SVL = 27.4 mm).

FIGURE 10. Dorsal (a), ventral (b) and lateral (c) view of N. vasanthi (SVL = 36.2 mm).

FIGURE 1. A male specimen of N. dattatreyaensis sp. nov. in life.

FIGURE 4. 4 a, right hand (Scale bar = 10 mm), TP, thumb pad and 4 b, right foot (scale bar = 12 mm) of holotype of N. dattatreyaensis sp. nov. (ZSI / WGFRS / V / A / 646).

Tables

TABLE 1. Some morphometric data (in mm) for the type series of N. dattatreyaensis sp. nov. Prefix ZSI / WGFRS / V / A for holotype and all paratypes.

SVL HW HL HD	40.0 15.2 12.2 10.2	41.0 16.0 12.4 10.0	36.2 16.0 12.4 9.0	38.4 16.0 12.2 10.4	38.9 ± 2.09 (36.2 – 41.0) 15.8 ± 0.40 (15.2 – 16.0) 12.3 ± 0.12 (12.2 – 12.4) 9.9 ± 0.62 (9.0 – 10.4)	37.2 14.6 12.4 8.4	38.0 15.0 12.0 9.0	37.6 ± 0.57 (37.2 – 38.0) 14.8 ± 0.28 (14.6 – 15.0) 12.2 ± 0.28 (12.0 -12.4) 8.7 ± 0.42 (8.4 – 9.0)
MN	10.2	10.0	9.6	10.4	10.1 ± 0.34 (9.6 – 10.4)	9.8	9.2	9.5 ± 0.42 (9.2 – 9.8)
MFE	8.2	8.4	7.6	8.2	8.1 ± 0.35 (7.6 – 8.4)	8.0	7.2	7.6 ± 0.57 (7.2 – 8.0)
MBE IFE	4.2 6.0	5.0 6.4	4.0 5.2	4.2 6.4	4.4 ± 0.44 (4.0 – 5.0) 6.0 ± 0.57 (5.2 – 6.4)	4.6 5.2	4.0 5.4	4.3 ± 0.42 (4.0 – 4.6) 5.3 ± 0.14 (5.2 – 5.4)
IBE	14.0	14.0	12.0	13.8	13.5 ± 0.97 (12.0 – 14.0)	13.0	13.2	13.1 ± 0.14 (13.0 -13.2)
FLL	9.2	10.0	9.2	10.0	9.6 ± 0.46 (9.2 – 10.0)	8.6	7.4	8.0 ± 0.85 (7.4 – 8.6)
HAL TL FOL IN	9.2 18.8 18.2 3.0	8.8 19.2 19.0 4.0	9.0 17.4 17.4 3.2	10.4 18.4 19.2 3.8	9.4 ± 0.72 (8.8 – 10.4) 18.5 ± 0.77 (17.4 – 19.2) 18.5 ± 0.82 (17.4 – 19.2) 3.5 ± 0.48 (3.0 – 4.0)	8.6 18.4 16.8 3.0	9.6 17.8 17.2 3.2	9.1 ± 0.71 (8.6 – 9.6) 18.1 ± 0.42 (17.8 – 18.4) 17.0 ± 0.28 (16.8 – 17.2) 3.1 ± 0.14 (3.0 – 3.2)
EN	2.8	3.2	3.0	3.0	3.0 ± 0.16 (2.8 – 3.2)	3.0	3.0	3.0 ± 0.00 (nil)
EL	5.0	5.0	4.4	5.0	4.9 ± 0.30 (4.4 – 5.0)	5.0	5.0	5.0 ± 0.00 (nil)
TFL FTL	4.8 10.4	5.2 10.2	5.0 10.0	5.0 10.4	5.0 ± 0.16 (4.8 – 5.2) 10.3 ± 0.19 (10.0 – 10.4)	5.0 8.4	5.0 9.2	5.0 ± 0.00 (nil) 8.8 ± 0.57 (8.4 – 9.2)
MTTF	11.2	12.0	11.2	12.4	11.7 ± 0.60 (11.2 – 12.4)	11.0	11.2	11.1 ± 0.14 (11.0–11.2)
TFTF	5.8	6.2	6.0	6.4	6.1 ± 0.26 (5.8 – 6.4)	4.8	6.0	5.4 ± 0.85 (4.8 – 6.0)
MTFF FFTF IMT ITL	11.8 5.4 3.2 3.4	13.0 7.2 3.0 3.0	12.2 6.4 3.2 3.6	12.4 6.6 3.4 3.6	12.4 ± 0.50 (11.8 – 13.0) 6.4 ± 0.75 (5.4 – 7.2) 3.2 ± 0.16 (3.0 – 3.4) 3.4 ± 0.28 (3.0 – 3.6)	10.6 7.0 2.6 3.0	12.0 7.2 3.0 3.6	11.3 ± 0.99 (10.6 – 12.0) 7.1 ± 0.14 (7.0 – 7.2) 2.8 ± 0.28 (2.6 – 3.0) 3.3 ± 0.42 (3.0 – 3.6)
FL	17.6	20.2	18.0	18.8	18.7 ± 1.15 (17.6 – 20.2)	17.4	17.0	17.2 ± 0.28 (17.0 – 17.4)
IUE	9.2	10.2	9.4	9.2	9.5 ± 0.48 (9.2 – 10.2)	9.6	9.0	9.3 ± 0.42 (9.0 – 9.6)
NS SL	3.8 7.0	3.4 6.4	3.8 6.2	3.8 6.4	3.7 ± 0.20 (3.4 – 3.8) 6.5 ± 0.35 (6.2 – 7.0)	3.8 7.0	4.2 7.0	4.0 ± 0.28 (3.8 – 4.2) 7.0 ± 0.00 (nil)
TFOL	25.0	26.4	23.2	25.4	25.0 ± 1.34 (23.2 – 26.4)	22.2	24.2	23.2 ± 1.14 (22.2 – 24.2)
TW	6.8	7.0	5.8	6.6	6.6 ± 0.53 (5.8 – 7.0)	6.0	6.0	6.0 ± 0.00 (nil)
UEW BWBS BWWL IOS	2.0 17.4 15.0 4.0	2.2 18.8 15.0 5.0	1.8 17.0 14.0 4.0	2.0 17.4 14.4 3.8	2.0 ± 0.16 (1.8 – 2.2) 17.7 ± 0.79 (17.0 – 18.8) 14.6 ± 0.49 (14.0 – 15.0) 4.2 ± 0.54 (3.8 – 5.0)	2.2 17.2 14.4 3.2	2.2 17.0 13.0 3.4	2.2 ± 0.00 (nil) 17.1 ± 0.14 (17.0 – 17.2) 13.7 ± 0.99 (13.0 – 14.4) 3.3 ± 0.14 (3.2 – 3.4)
AG	11.6	13.0	11.6	12.0	12.1 ± 0.66 (11.6 – 13.0)	13.4	13.0	13.2 ± 0.28 (13.0 – 13.4)
FGL	7.6	8.0	8.0	8.0	7.9 ± 0.20 (7.6 – 8.0)	-	-	-
FGW	4.2	5.0	3.2	3.4	4.0 ± 0.82 (3.2 – 5.0)	-	-	-