Leptolalax khasiorum, Das, Indraneil, Lyngdoh, Ronald K., Rangad, Duwaki & Hooroo, Rupa N. K., 2010

Das, Indraneil, Lyngdoh, Ronald K., Rangad, Duwaki & Hooroo, Rupa N. K., 2010, A new species of Leptolalax (Anura: Megophryidae) from the sacred groves of Mawphlang, Meghalaya, north-eastern India, Zootaxa 2339, pp. 44-56 : 46-54

Leptolalax khasiorum new species

( Figs. 2–4 )

Holotype: ZSI A10955 (ex-ID 9329) from Mawphlang (25°26'80.8"N, 91°44'99.8"E, alt. 1,813 m asl.; datum wgs-84), East Khasi Hills District, Meghalaya State, north-east India. 6 March 2009. I. Das, R. Lyngdoh & D. Rangad.

Paratypes: ZSI A10953–54, A10956 –59 (ex-ID 9327–28, 9330–33), paratopotypes. Collecting date and collectors as above.

Diagnosis: We allocate the Mawphlang specimens to Leptolalax for showing the following characters diagnostic for metamorphosed members (i.e., non-larval characters) of the genus ( Dubois 1980; 1983; 1987 "1986"; Delorme et al., 2006; Malkmus et al., 2002): palpebral projections absent; vomerine teeth absent; finger tips rounded, not disk-like; fingers lacking webbing; basal webbing of toes; limbs relatively long and slender; indistinct subarticular tubercle; inner palmar tubercle does not extend to first metacarpal; low inner metatarsal tubercle; outer metatarsal tubercle absent; nuptial pads absent; presence of macroglands (preaxillary, pectoral, ventrolateral and femoral) on body; bright iris pigmentation mostly restricted to upper orbit; females larger than males and ova unpigmented. A medium-sized (SVL 27.3 mm in the largest of four adult males, 33.4 mm in the largest of three adult females) species of Leptolalax , diagnosable from congeneric species in showing the following combination of characters: SVL 24.5–27.3 (mean 25.63 ± 0.61 SE) mm in males; 31.2–33.4 (mean 32.50 ± 0.67 SE) mm in females; dorsum with fine scattered tubercles; eyelids with tubercles; tympanum and supratympanic fold distinct; macroglands, including preaxillary, pectorals and ventrolateral glands present; Finger I> II; toe tips not dilated, bearing dermal fringes; dorsum with dark blotches; flanks with large dark blotches; dark tympanic mask present; venter lacking dark blotches; labial bars present and limbs with dark cross-bars.

(2009); Rowley & Trung (2009); Das (unpubl.).

TABLE 2. Mensural and meristic data for adults of Leptolalax khasiorum sp. nov., compared with congeneric species. References: 1. Male SVL (maximum, unless range given, in mm); 2. Female SVL

maximum, unless range given, in mm); 3. Head wider than long (0), longer than wide (1) or as long as wide (2); 4. Snout acuminate (0) or bluntly rounded (1) in dorsal view; 5. Snout smooth (0) or

tubercles (1); 6. Eyelids mostly smooth (0) or with tubercles (1); 7. Tympanum covered with skin (0) or exposed (1); 8. Tympanum - eye proportion; 9. Supratympanic fold indistinct (0) or distinct

10. Dorsum smooth or weakly shagreened (0), tuberculate (1) or ridged (2); 11. Ventrolateral glandular ridge absent (0) or present (1); 12. Pectoral gland absent (0) or present (1); 13. Preaxillary

absent (0) or present (1); 14. Fingers I and II subequal (0), Finger I> II (1) or Finger II> I (2); 15. Vocal sac single, median, subgular (0), paired, median, subgular (1), indistinct or absent (2) or

slit present (3); 16. Toe webbing absent (0), basal (1) or extensive (2); 17. Lateral fringes on toes absent (0), weak (1) or extensive (2); 18. Subarticular tubercles on pes non-keratinized (0) or

keratinized (1); 19. Subarticular tubercles indistinct or absent (0) or distinct (1); 20. Dorsum unpatterned (0), with dark spots (1) or pale spots (2); 21. Dark tympanic mask or spot absent (0) or present

22. Dark vertical labial bars absent or indistinct (0) or distinct (1); 23. Flanks unpatterned (0), with small (1) or large (2) spots; 24. Venter unpatterned (0), with dark spots or streaks (1), dark

marbling or network (2) or pale speckling (3); 25. Thigh posterior unpatterned (0) or with black reticulation enclosing pale spots (1); 26. Forearm undifferentiated from upper arm (0) or paler than upper

(1); 27. Limbs pale (0) or with dark cross-bars (1); and 28. Body venter pale (0) or dark (1). In addition, '?' denotes an unknown character state; '/' denotes a multistate character; '-' denotes not

applicable.

Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

alpinus 24.0– 31.7– 2 1 0 0 1 ½ 1 0 1 1 0 0 0 1 2 0 0 1 1 1 1 1 0 0 1 0 26.0 32.5

applebyi 19.6- 21.7 1 1 0 1 1> 0 0 0 1 1 2 2 1 0 0 0 0 1 1 1 3 0 1 1 1 20.8 ½

36.0 38.0 1 1 1 1 1 ½ 1 0 0 0 0 0 0 1? 0 0 1 1 0 2 1 0 0 1 0

bourreti 36.2 42.0– 0 1 0 1 1 ½- 1 1 1? 1 0 0 1 2 0 0 1 1 1 2 0? 0 1 0

45.0 3/5

30.0– 37.0– 1 1 1 0 1 ½ 1 1 0 0 1 0 0 0 0 0 0 0 1 1 2 1 0 0/1 1 0 35.0 48.0

fuliginosus 28.2–? 1 1 0 0 1 ½ 1 0 1 1 1 2 0 1 1 0 0 1 1 1 2 1 1 0 1 1 30.0

gracilis 31.0– 40.0– 1 1 1 1 1 <1 1 0 0 1 2 0 1 1 0 0 1 1 1 2 1 0 1 1 0 39.0 48.0 ½

hamidi 28.0– 36.0– 1 1 0 0 1 ½ 1 1 0?? 0 0 1? 0 0 1 1 1 2 0 0 0 1 0 31.0 43.0

heteropus 24.2– 32.0–? 1 0 1 1 <1 0 0???????? 1 1 1 1 1 0 1 1 0 29.0 36.0 ½

kajangensis 34.0–? 1 1 0 0 1 <1 0 0?? 0? 1 0 0 0 0 1 1 0 0 0 0 0 1 35.0 ½

19.3– 25.0 1 1 0 0 1 <1 1 0 1 0 1 0 1 1 0 0 1 1 1 0 1 1 0 1 1 20.5 ½

khasiorum sp. 24.5– 31.2– 0 1 0 1 1 ½ 1 1 1 1 1 2 0 1 0 0 0 1 1 1 1 1 0 0 1 0

. 27.3 33.4

lateralis 26.9– 28.3 0 1 1 1 1 ½ 1 1 1 1? 2 2 1 0 0 0 1 1 1 0 0 1 0 1 0 28.3

26.3 23.1– 2 1 1 1 1 <1 0 1 1 0 0 0 1 2 0 0 1 1 1 2 1 1 0 1 0

28.1 ½

maurus 26.1 31.8 0 1 1 1 1> 1 1 0 1? 0? 1? 0 0 2 0 0 1 1 0 0 1 1

½

melanoleucus 26.6– 32.7 1 1 0 0 1 ½ 1 0 0 1 1 2 0 1 0 0 0 1 1 1 1 1 0 0 1 0 29.0

nahangensis 40.8? 2 1 0 0 1 ½ 1 0 0 1 1 1 3 1 0 0 1 1 1 1 2 0 0 0 1 0

oshanensis 26.6– 31.6 2 1 0 0 1 <1 2 1 0/1 1 0/2 0 0 0 0 0 1 1 1 1 0 0 0 1 0 30.7 ½

pelodytoides 27.7– 35.3– 0/2 1 0 0 1 ½ 1 1 1? 0 0 1 1/2 2? 0 1 1 0 2 0 0 0 1 0 30.9 40.7

30.0– 39.0– 1 1 0 1 1 ½ 1 0 0 0 0 0????? 1 1 1 2 0 0 0 1 0 35.0 47.0

pluvialis 21.3–? 1 1 0 0 1 ½ 1 0 1 1 1 2 2 0 0 0 1 1 1 0 2 0 0 1 1 22.3

23.0–? 1 1 0 0 1 <1 1 0 1 0 1 0 1 1 1 0 1 1 1 0 1 1 0 1 0 28.7 ½

48.3– 56.7– 0 0 1 1 0 ½ 1 1 0 1 0 0 0 1 1 1 0 2 1 1 1 0 0 0 1 0 52.7 58.9

tuberosus 24.4– 30.2 2 1 1 1 0 - - 1 1 1 1 1 0 1 1 0 1 0 2 1 1 1 1 0 1 0 29.5

ventripunctatus 25.5–? 1 1 0 0 1 ½ 1 2 1 1 0 2 0 0 0 0 0 1 1 1 1 1 0 1 1 0 28.0

The presence of paired, pale ventrolateral and femoral glands in the new species separates it from all members of the southern lineage (subgenus Leptolalax ), including arayai , dringi , gracilis , hamidi , heteropus , kajangensis , kecil , maurus , melanoleucus , nahangensis , pictus and solus . From members of the northern lineage (subgenus Lalax ), it differs from alpinus , fuliginosus , liui , oshanensis , pluvialis , tuberosus and ventripunctatus in showing head wider than long; from lateralis in showing dark-spotted venter; from pelodytoides in showing preaxillary glands; from bouretti in showing Finger II> I; and from applebyi in showing distinct supratympanic fold. Table 2 lists mensural and meristic data for adults of the genus Leptolalax .

Description of holotype (ZSI A10955; adult male): SVL 25.0 mm; body moderately slender, narrow at waist; cloacal opening at upper level of thighs; head wider than long (HW/HL ratio 1.29); snout obtusely pointed when viewed dorsally and laterally; projecting slightly beyond mandible; palpebral projections absent; nostrils not raised and lack dermal flaps; dorsolaterally positioned, situated slightly below canthus, nearer tip of snout than to eye (E-N/E-S ratio 0.57); internarial distance greater than distance from anterior margin of eye to nostril (IN/E-N ratio 1.48); eye large (ED/HL ratio 0.51); its diameter greater than eye to nostril distance (ED/E-N ratio 1.81); pineal ocellus absent; interorbital space flattened, interorbital width greater than upper eyelid width (IO/UE ratio 1.57); canthus rostralis obtuse; loreal region sloping; no symphysial knob on anterior edge of mandible; mouth extends to beyond posterior corner of eye; choanae located against anterior of palate, visible when viewed from below; vomerine teeth absent; tongue subtriangular, elongate, bifid, free for approximately half its length, lacking papillae and median lingual process; pupil elliptical; tympanum distinct, oval, separated from orbit of eye by a distance 44.4% of horizontal diameter of tympanum; tympanic rim narrow but prominent; supratympanic fold from posterior corner of orbit to above insertion of forelimbs.

Fore limbs short; forearm not enlarged; fingers slender, free of web or skin fringes; relative length of fingers: III> II> I> IV; finger tips rounded, not dilated; subarticular tubercles indistinct; outer metacarpal elongate, about a third size of rounded inner metacarpal tubercles, the two separated anteriorly by a distinct furrow; inner metacarpal tubercle not extending out under Finger I; nuptial pads absent on fingers.

Hind limbs moderately short (TBL/SVL ratio 0.50); heels widely separated when hind limbs are flexed and held perpendicular to body; toe- tips not differentiated, truncate apically; distinct lateral fringes present on inner aspects of all toes; toes webbed up base of phalanges; relative length of toes: 4> 3> 5> 2> 1; subarticular tubercles indistinct; distinct ridges on undersurfaces of toes; no outer metatarsal tubercle; a large, compressed inner metatarsal tubercles; keratinized dermal ridges replace subarticular tubercles, covering entire undersurfaces of toes.

Dorsum with isolated, spinous tubercles, largest on flanks, where they are flattened; snout smooth; upper eyelids with small tubercles; vocal sac indistinct on throat; vocal opening close to rictus; sacral region and dorsal surfaces of thigh and tibia with low tubercles; tarsal fold present; gular, pectoral, abdominal regions, undersurfaces of forelimbs and shanks smooth; undersurface of thighs finely glanular; macroglands present include small, oval preaxillary glands (largest axis = 1.1 mm) in front of forearm; large (1.7 mm), oval, flattened pectoral glands at insertion of forearms; elongate (6.6 mm) ventrolateral glands on lower flanks; large (1.4 mm), oval femoral glands on lower half of femur, closer to knees than to vent; small (0.6 mm) paired, oval, preanal glands below vent; low tubercle project over vent.

Colour: In life, forehead and dorsum brownish-grey, with irregular mid-brown or dark grey blotches; an inverted, hourglass-shaped dark grey blotch in interorbital region; flanks with blackish-grey blotches that encircle pale tubercles and sometimes join adjacent tubercles; tympanum brownish-grey, with a short greyishbrown mask covering top third at edge of supratympanic fold; dark greyish-black stripe across rostral region, along snout-tip; top third of iris bright orange, rest of iris (except for a small area on lower iris which has a bright orange flash) yellowish-cream, edged peripherally with irregular black radiating lines; outer edges of eyes dark brown; labials with greyish-black bars; tubercles on dorsum and hind limbs pinkish-red; preaxillary gland pinkish-red; upper surfaces of fore and hind limbs brownish-grey with dark grey bands; phalanges pale grey with dark grey crossbars; dorsal surfaces of Fingers I–II distinctly paler than those of Fingers III–IV; undersurfaces of forearm, anterior edge of thighs and shanks with distinct dark grey variegation; undersurfaces of thighs dark grey with cream coloured oval spots; hand and feet dark grey; gular and abdominal regions pale grey, with scattered dark grey pigments; abdominal region unpatterned cream medially, with darker pigments restricted to the sides; pectoral, ventrolateral and femoral glands pale pink, with narrow dark edges; pale preanal glands.

Variation: Measurements of the holotype and the six paratopotypes are in Table 3. Apart from a significant (U-test; p <0.05) difference in body size, male SVL range 24.5–27.3 mm vs. female SVL range 31.2–33.4 mm, there was no other secondary sexual dimorphism.

head, HL, upper UE IMT;,. female BW 9.1 10.4 12.8 11.2 10.88 ± 0.77 17.0 14.8 12.8 14.87 ± 1.21;; length F =

distance distance tibia, male; A-G 11.5 11.6 10.9 11.7 11.43 ± 0.18 17.2 13.0 12.4 14.20 ± 1.51

;

internarial, IN tympanum

eye

to TBL length; = Additionally, M IMT IPT 1.4 1.5 1.5 1.7 1.5 1.7 1.8 1.7 1.63 1.58 ± ± 0.08 0.08 1.6 2.0 1.4 2.0 1.7 1.5 1.50 1.90 ± ± 0.06 0.10

length,; E-T, forelimb width. TBL 12.4 12.2 12.5 12.9 12.50 ± 0.15 14.5 14.3 14.8 14.53 ± 0.15 snout-vent SVL, distance nostril FL; diameter body, BW FL VTD 1.7 7.7 7.0 1.7 1.8 7.8 1.8 7.5 7.50 1.75 ± ± 0.18 0.03 8.8 2.2 8.8 2.4 9.1 2.0 2.20 8.90 ± ± 0.10 0.12: and

Abbreviations,; to eye E-N vertical tympanum groin distance HTD IO 1.8 4.7 1.8 5.4 4.4 1.8 2.2 5.5 5.00 1.90 ± ± 0.10 0.27 5.5 2.1 2.3 5.0 2.2 6.4 2.20 5.63 ± ± 0.06 0.41.. nov sp distance VTD, axilla to E-T UE 0.9 2.7 0.6 2.9 0.8 2.8 2.8 0.8 2.80 0.78 ± 0.06 0.04 1.1 3.6 2.6 1.0 1.1 2.7 1.07 2.97 ± 0.03 0.32 khasiorum E-S to eye snout,; diameter A-G; tubercle, E-S E-N 2.5 3.0 3.7 2.5 3.7 2.1 2.2 4.6 3.75 2.33 ± ± 0.10 0.33 4.0 2.8 2.7 4.1 2.7 4.7 4.27 2.73 ± ± 0.03 0.22 Leptolalax ; diameter tympanum palmar ED 3.4 3.3 3.8 4.1 3.65 ± ± 0.18 4.7 4.4 4.5 4.53 ± ± 0.09 of series eye vertical inner of HD 4.2 4.0 5.1 4.8 4.53 ± 0.26 5.1 5.0 5.1 5.07 ± 0.03

, type ED;, HTD length

the) of mm head depth distance;, IPT; HW HL 6.0 9.3 7.2 9.4 7.4 9.6 8.3 10.1 7.23 9.60 ± ± 0.47 0.18 11.7 7.8 10.8 8.8 8.3 11.3 8.3 11.27 ± ± 0.26 0.29 in (, HD tubercle IN 2.8 2.7 3.1 3.2 2.95 ± 0.12 2.6 2.6 3.1 2.77 ± 0.17 Measurements head; width, interorbital IO metatarsal SVL 24.5 25.7 25.0 27.3 25.63 ± 0.61 33.4 31.2 32.9 32.50 ± 0.67

,; 3. HW width of inner sex M M M M SE F F F SE TABLE; length eyelid length ZSI 10953 A A 10954 A 10955 A 10956 ± mean 10957 A 10958 A A 10959 ± mean Etymology: Latinized specific name after the major ethnic group (the Khasi) of the Khasi Hills, Meghalaya State, in north-eastern India. Many forests, such as the one from where the type series was collected, are protected as sacred forests by the Khasis, who are part of the Mon-Khmer linguistic family.

Ecological notes: Figure 5 shows the habitat and microhabitat of collection of the new species at the type locality. The vegetation of Mawphlang is classified as subtropical wet hill forest ( Champion and Seth 1968). Khan et al. (1987) reported that the tree flora of the sacred grove of Mawphlang is dominated by alpine elements, including Quercus dealbata, Schima khasiana, Manglietia insignis, Corylopsis himalayana, Phyllanthus glaucus, Manglietia caveana and Myrica esculenta , growing on nitrogen-rich lateritic soil. Mahony (2008) presented a non-collection-based inventory of the amphibian species of the site, and reported seven species, including Xenophrys cf. parva , Hylarana danieli , Philautus sp., Duttaphrynus melanostictus , Amolops cf. gerbillus, Fejervarya cf. teraiensis and an unidentifiable species of megophryid frog, and reported an additional six species from previous inventories (including Hylarana leptoglossa, Polypedates leucomystax, Rhacophorus bipunctatus, Hyla annectans, Euphlyctis cf. hexadactylus and Amolops formosus ). The three females bear relatively large, unpigmented eggs, suggesting spring breeding, ahead of the Southwest Monsoons (between May and September in the area). Acoustic data and other ecological traits of the new Leptolalax remain unknown.

Figures

FIGURE 2. Male holotype of Leptolalax khasiorum sp. nov. (ZSI A 10955), in life. A. Lateral view; B. Ventral view; C. Head profile.

FIGURE 3. Holotype of Leptolalax khasiorum sp. nov. (ZSI A 10955). A. Right side of venter, showing distribution of macroglands. References: P = Pectoral glands; V = Ventrolateral glands; F = Femoral glands; B. Right hand and C. Right feet.

FIGURE 4. A female paratype of Leptolalax khasiorum sp. nov. (ZSI A 10957), in life. A. Lateral view; B. Ventral view.

FIGURE 5. Habitat and microhabitat of Leptolalax khasiorum sp. nov. at Mawphlang, Meghalaya State, north-eastern India. A. Mawphalang, a sacred grove protected by the Khasi tribe; B. Microhabitat at the time of sampling in the month of March was moist interstices of rocks along an intermittent hill stream within a subtropical wet hill forest.