Duttaphrynus chandai, Das, Abhijit, Chetia, Mitali, Dutta, Sushil Kumar & Sengupta, Saibal, 2013

Das, Abhijit, Chetia, Mitali, Dutta, Sushil Kumar & Sengupta, Saibal, 2013, A new species of Duttaphrynus (Anura: Bufonidae) from Northeast India, Zootaxa 3646 (4), pp. 336-348 : 338-346

Duttaphrynus chandai new species

( Fig 2 & 3 , Table I)

Holotype: ZSIC A 11453, adult male from Khonoma village, 25° 38. 505’ and 94° 01.479’, 1568 m. asl., collected on 18th march 2008, small rocky first order stream, ca. 2-4 m wide at the collection location. Collected by A. Das and P. Choudhury.

Paratypes: Adult females (ZSIC A 11456 ) and a sub-adult female (ZSIC A11455) from Khonoma village, 25° 38. 505’ and 94° 01.479’, 1568 m. asl., collected on 18th march 2008, small rocky 1st order stream; adult females ZSIC A 11454 and AVCM A1044 from Thekhekhwei hill, 25° 38. 071’ and 93° 56.652, 1787m. asl., 5 km east to Khonoma village, Nagaland state of India, 29 September 2010, at 1830 h., from a slash and burn (Jhum) cultivation area close to a small rocky stream. Collector A. Das; adult male AVCM A 0 964, 25° 37. 733’ and 94° 00.623’, 1775 m. asl., Hievibakie hill, 8 km east to Khonoma village, 16 September 2009 at 0 800 h. near Dzuku Base camp, under rotten log ca. 5 m away from motorable gravel road. Collector A. Das.

Diagnosis: These specimens were allocated to Duttaphrynus for showing the following suit of diagnostic characters: presence of cranial ridges, parotid glands; fingers free with moderate toe webbing, rough and tuberculated skin, absence of parietal ridge, tarsal ridge and tibia gland.

This new species is diagnosable from congeneric species in showing the following suite of characters: Large size (adult male, 67.5–88.1 and female, 61.2–86.1 mm), head much wider, tympanum hidden or partly visible under a skin fold, small eye, obscure cranial ridges, fingers long and thin, pointed warts and presence of a cream coloured mid dorsal line. Morphometric and mesural features of holotype and paratypes are listed in Table I

Description of holotype (ZSIC A 11453; adult male): A large toad (SVL 67.5 mm), habitus stout, cloacal opening at upper level of thighs; head large (HL/SVL ratio 0.29) wider than long (HL/HWAJ ratio 0.82), and about three and half times of its depth (HL/HDN ratio 3.55); snout more than one third of head length (SL:HL ratio 0.39), obtusely pointed when viewed dorsally and laterally; barely projecting beyond mandible; angle of jaw extends beyond posterior corner of the eye up to the anterior part of the parotid; nostrils rounded not raised and with a marginal dermal flap on dorsal side, placed dorsolaterally, nearer to the tip of snout than to eye (EN/NS ratio 1.09); internarial distance smaller than inter orbital distance (INS/IOS ratio 0.60) but equal to distance from anterior margin of eye to nostril (INS/EN ratio 1.00); eye large (ED/HL ratio 0.37); its diameter greater than eye to nostril distance (ED/EN ratio 1.75); pineal ocellus absent; interorbital space flattened; canthus rostralis slightly oblique; loreal region greatly concave; a highly depressed symphysial knob on anterior edge of mandible; Choanae rounded and well separated, vomerine ridge posterior to choanae and perpendicular to the body axis.; tongue oval, two lateral flaps at free end, lacking papillae and median lingual process; pupil elliptical; tympanum slightly visible mostly hidden under skin fold. Canthal, supraorbital and parietal cranial ridges present. Parotid gland wide and elongated (PGL: PGB ratio = 3.12), less than ¹/3 rd of SVL (PGL: SVL ratio 0.27), separated from each other by a distance (10.82 mm) less than its length (PGL 17.98 mm).

Fore limbs moderately long (FLL/SVL ratio = 0.88) and stout; fingers slender, free of web; relative length of fingers: II<I<IV<III; finger tips round slightly swollen; subarticular tubercles prominent; outer metacarpal large and oblong; inner metacarpal tubercle small elongated not extending out under finger I. Hindlimb long (HLL:SVL ratio 1.39), Tibia long (TBL/SVL ratio 0.43), more than three and half times of its width (TBL/TBW ratio 3.60); tibia tarsus articulation reaches the middle of the parotid gland; heels remain seperated when hind limbs are flexed and held perpendicular to body; toe tips weakly differentiated, not truncate apically; lateral fringes present on all toes; relative length of toes: 1<2<5<3<4; Toe webbed (Webbing formula I 1 ½-1½ II 1 ½-2½ III 1 ½-3½ IV 3 ½-1½ V. Subarticular tubercles on toes indistinct; super numerary tubercles on hands and toes; outer metatarsal tubercle depressed; an elongated inner metatarsal tubercles (IMT:Toe I ratio 0.30); cloacal opening directed posteroventrally, little below the upper level of the thigh. Skin on dorsal surface granulated, with irregularly arranged scarce pointed tubercles. Head between eye smooth, flat tubercles on upper eyelid, large irregular shaped tubercle on tympanic region, a patch of irregular wart behind eye; two rows of enlarged tubercles on flank; forelimb upper part with small pointed tubercles, hindlimb upper surface with large pointed tubercles. Ventrally trunk and chin warty; lower part of shank and foot finely tuberculated, thigh with large flat tubercles.

Condition of the type series: The Type series (ZSIC A 11453, ZSIC A 11454, ZSIC A 11455, ZSIC A 11456 , AVCM A 0 964 and AVCM A 1044) was well preserved. However, all the type specimens had lateral incision which was made to determine the sex of the individual. In the holotype (ZSIC A 11453) and paratype (AVCM A 0964) a small incision was made to remove thigh (upper) muscle for future molecular analysis.

Secondary sex characters: male: Presence of a small nuptial pad at the base of first finger. The breeding male developed reddish tinge on dorsum; warts were large, flat and without black tip; digit tips were not melanistic. A thin line on the ventral side from snout to vent and also undersurface of limbs.

Adult females (SVL: 81.0— 86.1 mm) were almost equal to the males (SVL: 58.0— 88.1 mm) and with hidden tympanum, comparatively rough dorsum, melanistic digital tips and wart tips.

Colour: In life, forehead and trunk brown with black blotches, more intense between the parotid; laterally pale yellow. Canthus yellow. Parotid black with yellow dots. An obscure yellow mid dorsal line extended from snout to vent. Upper surfaces of fore and hind limbs pale brown with dark brown patches, phalanges pale brown. Trunk on ventral aspect dirty white with variegated brown patches, rest of the ventrum dusty white.

Variations: A female (ZSIC A 11456 ) head was comparatively wider (HL: HW = 0.70) than other members of the type series (HL:HW = 0.84 + 0.02). The female paratype (ZSIC A 11454) showed partial parietal ridge. A great variation in the shape of the parotid gland also occurred amongst the members of the type series. The parotid gland was elongated (ZSIC A 11453, A ZSIC A 11455, ZSIC A 11456 , AVCM A 0964) except in ZSIC A 11454 and AVCM A 1044 where it was bean shaped. One female (ZSIC A 11455) had alternate light and dark bands on hind limb.

Etymology: Named after Shyamal Kumar Chanda, a prominent Indian amphibian biologist. Suggested common name: Nagaland Montane torrent toad

Ecological notes: The type locality of Khonoma, situated ca. 20 km west of Kohima (Nagaland State capital), runs along a ridge extending from the terraced rice field in the valley up to the uplands of the Barail hill range. This domain, spreading over ca. 123 sq. km., includes Khonoma Nature Conservation and Tragapon Sanctuary covering an area of over 70 sq. km. The forested slopes of the village are relatively undisturbed, baring a few patches of jhum-cleared cultivations. Khonoma enjoys a sub-tropical to temperate climate with heavy rains from the month of May to August and little rainfall during September to October. The dry season is usually from the month of November till April. The environmental temperature in the summer months goes up to a maximum of 30ºC and a minimum of 4ºC. This area is the part of Mizoram-Manipur-Kachin Rain Forest biogeographic zone and is characterized by subtropical broadleaf hill forest and Rhododendron forest. The new species of toad was observed both during day and night between March to September in recently felled Jhum cultivation field, forest trail and under rotten log at altitude from 1568 to 1762 m ( Fig 4 ). Breeding aggregation was observed in small streams (width ~ 2–4 m) of first order (Strahler, 1952) near human habitation and forest edges. The individuals were found to use stagnant water pool with accumulated leaf litter. The water pools of the streams were surrounded by large rocks. Calling males were recorded on a cloudy day (10.25 AM IST) of 18 March 2008 with environmental parameters as air temperature 13.8o C, water temperature 11o C, humidity 77%, water pH 7.8. Eggs were laid in long string inside thick gelatinous mass and advanced embryos (Gosner stage 16–18) were observed in “side water pool” of a small stream (first order) beside terrace cultivation on 21 March 2008 ( Fig 5 ). Eggs were rounded with pigmented animal pole. The breeding period coincided with early breeders like Rhacophorus burmanus , Rhacophorus maximus and Hyla annectens in the region. During the breeding season, this species ( D. chandai ) is relatively abundant and observed in modified as well as forested habitats not far from flowing water sources.

85.0 (Ƥ) Juveniles observed in the month of September-October inhabiting forest floor and roadside habitats. This species is locally called as “Theiiu” in Angami Naga dialect. The species was observed between elevations 1568 and 1787 m. Currently the species is only known from localities around Khonoma and Dzuleke villages of Kohima district.

Syntopic species of anurans recorded from the type locality are Duttaphrynus himalayanus , Rhacophorus burmanus , Hyla annectens, Amolops sp, Rhacophorus maximus . The reptile species found in sympatry are Calotes jerdoni, Sibynophis collaris, Protobothrops jerdoni, Ovophis monticola, Rhabdophis nuchalis and Ptyas nigromarginatus .

Comparison: From other members of the genus Duttaphynus, the new species differs in showing the following characters, listed by species (characters in parentheses refer to congener being compared with the new species from Khonoma)

The new species differs from D. melanostictus (Schneider) in showing smaller snout, comparatively longer mandible eye distance, absence of tympanum, longer tibia, absence of preorbital, postorbital and orbitotympanic ridges, 1st finger longer than 2nd (vs. smaller size, longer snout, smaller mandible eye distance, distinct tympanum, smaller tibia, presence of preorbital, postorbital and orbitotympanic ridges, 2nd finger longer than 1st), from D. himalayanus (Günther) in showing 1st finger longer than second, absence of tympanum, preorbital, postorbital and orbitotympanic ridges (vs. 2nd finger longer than 1st, presence of tympanum, preorbital, postorbital and orbitotympanic ridges), from D. stuarti (Smith) in showing cranial ridges, absence of tympanum, subarticular tubercle not prominent (vs. without bony ridges, distinct tympanum, prominent subarticular tubercle); from D. cyphosus (Ye) in showing elongated and broad parotid, indistinct or absence of tympanum, absence of bracket like curves on interorbital space (vs. triangular parotid, small distinct tympanum, dark round curves facing each other like ‘brackets’ along the supraorbital ridge); from D. scaber (Schneider) in showing elongated parotid gland, absence of tympanum, preorbital, postorbital and orbitotympanum ridges, 1st finger longer than the 2nd, toe webbing: I1 ½–1½ II1 ½–2½ III1 ½–3½ IV3 ½–1½V (vs. rounded parotid gland, tympanum about ½ of the eye diameter, presence of preorbital, postorbital and orbitotympanic ridges, 1st finger smaller than 2nd, toe web I0— 1 II1-2III2–3 ½ IV3 ½– 1V), from D. crocus (Wogan, Win, Thin, Lwin, Shein, Kyi, and Tun) in showing absence of preorbital, postorbital and orbitotympanum ridges, 1st finger longer than the 2nd, toe webbing: I1 ½–1½ II1 ½– 2½ III1 ½–3½ IV3 ½–1½V (vs. presence of preorbital, postorbital and orbitotympanum ridges, 1st finger smaller than the 2nd, toe webbing: I2–3II1–2 ½ III1 ½–3½ IV3 ½–1½V); from D. stomaticus (Lütken) in showing cranial ridges, absence of tympanum, longer hind limb (vs. no cranial ridge, distinct tympanum, short hind limb); from D. kiphirensis (Mathew and Sen) , D. manipurensis (Mathew and Sen) , D. mizoramenis (Mathew and Sen) , D. mamitensis (Mathew and Sen) , D. nagalandensis (Mathew and Sen) , D. wokhaensis (Mathew and Sen) in showing absence of distinct tympanum, and absence of preorbital, postorbital and orbitotympanic ridges (vs. distinct tympanum and presence of preorbital, postorbital and orbitotympanic ridges) ( Fig. 6 ). The new species also shows differences from Ingerophrynus macrotis (Boulenger) in showing absence of tympanum, strong parietal ridge (vs. distinct tympanum, weak parietal ridge), from Bufo pageoti Bourret in showing cephalic ridges, absence of pineal ocellus, toe webbing: I1 ½–1½ II1 ½–2½ III1 ½–3½ IV3 ½–1½V (vs. no cephalic ridge, presence of pineal ocellus, toe webbing: I1–1 ½ II1–2III1–2 ½ IV2 ½– 1V) and from Phrynoidis aspera (Gravenhorst) in showing absence of tympanum, toe web incomplete, TTA reaches to the parotid gland, parotid broad and elongated, absence of orbitotympanic ridge (vs. distinct tympanum, toes entirely webbed, TTA reaches tip of snout or beyond, parotid small and triangular, presence of orbitotympanic ridge).

Mathew and Sen (2009) described six new species of Duttaphrynus based on seven specimens collected from Northeast Indian states. We conducted PCA involving the holotypes of Mathew and Sen (op cit) species, and compared with Duttaphrynus melanostictus and specimens of new species described herein ( Fig 7 ). We have observed D. wokhaensis to be deeply embedded into the D. melanostictus cluster. Mathew and Sen (2009) also pointed out its close affinity to D. melanostictus and D. himalayanus .

Mathew and Sen (2009) stated that D. wokhaensis differed from D. melanostictus and D. himalayanus in having nostril equidistant from eye and snout tip and, white cranial ridges and warts. The examination of holotype (V/A/ERS/ZSI/800) revealed that the morphometry of this specimen fall in the range of morphometry of D.

melanostictus and the specimen has the nostril closer to the snout than the eye (EN = 4.85; NS = 3.57). Further, stray individuals having white cranial ridges and warts were collected from amongst D. melanostictus population of Guwahati (AVCM A0326) and Tangla (AVCM A0850). We consider D. wokhaensis as a variety of D. melanostictus and we propose to keep this species under nomen D. melanostictus .

Colouration is well known to be highly variable in many groups of anurans especially in highly polymorphic group like Duttaphrynus melanostictus and is seldom useless in taxonomy (Qiucke, 1993). Thus we presume that difference in colour as reported in D. wokhaensis may be intraspecific variation.

ZSI/ ZSI/ ZSI/ ZSI/ ZSI/ ZSI/ Mus. ERS ERS ERS ERS ERS ERS No A0894 A0896 A0893 A0898 A0895 A0899 A0891 A0884 A0890 A0885 794 798 795 800 799 796

Figures

FIGURE 2. Dorsal and ventral view of the Holotype of D. chandai sp. nov. (ZSIC A 1453)

FIGURE 4. Thekhekhwei hill near Khonoma village

FIGURE 5. Egg strings of Duttaphrynus chandai in the side water pool of first order stream in Khonoma, Nagaland.

FIGURE 6. Lateral view of head showing distinct tympanum in A. D chandai, Holotype (in life (3, ZSI A 11453); B. D. chandai (3, AVCM A 1072); C. D. chandai, (Ƥ, paratype, A 1044); D. D. stuarti, (3, A 0743); E. D. melanostictus (Ƥ, A 0616); F. D. wokhaensis (Ƥ, SVL 88.69); G. D. kiphirensis (3, SVL 67.72); H. D. melanostictus (3, A 0850), SVL 55.5; I. D. mamitensis (Ƥ, SVL 88.93 mm); J. D. nagalandensis (Ƥ, SVL 49 mm); K. D. manipurensis (3, SVL 48.3 mm); L. D. mizoramensis (3, SVL 59.1 mm).

FIGURE 7. Scatter plot of components 1 and 2 resulting from PCA: Duttaphrynus chandai (male and Female), D. melanostictus (male and female), D. kiphirensis (male), D. manipurensis (male), D. mizoramensis (male), D. nagalandensis (male), D. wokhaensis (female), D. mamitensis (female).

FIGURE 3. A. Live photograph of Duttaphrynus chandai sp. nov. (A 1043) B. Side view of anterior body C. dorsal view of anterior body D. Ventrum E. Ventral view of hand F. Ventral view of the foot.