Megophrys ancrae Mahony, Teeling & Biju, 2013, sp. nov.
Creators: name: Mahony, Stephen
name: Teeling, Emma C.
name: Biju, S. D.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Megophryidae
Megophrys
Megophrys ancrae

description: Megophrys ancrae sp. nov.
(Figures 1–3; Table 1)
Holotype. Adult male (ZSI A 11606), from 6th mile (27°29.833’N 96°23.467’E, 420 m asl.) approx. 3 km from Deban Guest House, Deban, Namdapha National Park and Tiger Reserve, Changlang district, Arunachal Pradesh state, northeast India, collected by the Systematics Lab members, 2 June 2011.
Paratypes. Adult male (ZSI A 11607), collected along with the holotype. Four adult males (BNHS 5598, BNHS 5600–5602), one subadult and one adult female (ZSI A 11608, BNHS 5599, respectively), from Bornulla forest stream (27°32.367’N 96°28.650’E, 790 m asl.), Namdapha National Park and Tiger Reserve, Changlang district, Arunachal Pradesh state, northeast India, collected by the Systematics Lab members, 3 May 2011.
Referred specimens. Two adult males (SDB.DU 2009.727, 2009.730), from approx. 1 km before reaching Deban Guest House (27°29.846’N 96°23.470’E, 330 m asl.), Deban, Namdapha National Park and Tiger Reserve, Changlang district, Arunachal Pradesh state, northeast India, collected by the Systematics Lab members, 20 June 2009.
Diagnosis. Megophrys ancrae sp. nov. is diagnosable from geographically relevant congeners by the following combination of characters: medium-sized slender species, adult-male SVL 39.1–45.0 mm (N=8), adultfemale SVL 48.9 mm (N=1); HL>HW, HW/SVL 30.0–35.8% (N=10); SHL/SVL 46.0–55.3% (N=10); tympanum clearly defined, TYD /ED 50.0–63.2% (N=10); vomerine ridges small to medium-sized, weakly raised and circular; distinct dorsolateral folds present; subarticular, palmar and metatarsal tubercles absent; lateral fringes on toes absent; webbing between toes rudimentary; digit tips distinctly expanded terminally; protruding projection posterior to cloaca of males absent; dark spots on the throat present on most specimens; small, sharp, horn-like tubercle present on the eyelids of most individuals.
Comparisons. Megophrys ancrae sp. nov. differs from the following large-sized species by considerably smaller adult male size, SVL 39.1–45.0 mm, N=8 (vs. adult male SVL> 53 mm: M. gigantica Liu, Hu & Yang, N =6; M. glandulosa Fei, Ye & Huang, N =10; M. jingdongensis Fei & Ye, N=2; M. lekaguli Stuart, Chuaynkern, Chan-ard & Inger, N=8; M. major (Boulenger), N=8; M. medogensis Fei & Ye, N=16; M. omeimontis Liu, N =10; M. robusta (Boulenger), N=4; M. spinata Liu & Hu, N=2); from the following medium-sized species by smaller adult size, male SVL 39.1–45.0 mm, N=8, female SVL 48.9 mm, N=1 (vs. M. megacephala Mahony, Sengupta, Kamei & Biju male SVL 45.9–53.4 mm, N=7, female SVL 64.4 mm, N=1; M. takensis Mahony male SVL 47.3– 53.0 mm, N=3, female SVL 72.9 mm, N=1), further from M. megacephala by considerably narrower head, HW/ SVL 30.0–35.8%, N=10 (vs. HW/SVL 40.2–45.1%, N=9), and further from M. takensis by vomerine ridges small to medium-sized, weakly raised and circular (vs. elongated stalk-like projections); from the following small-sized species by larger adult size, male SVL 39.1–45.0 mm, N=8, female SVL 48.9 mm, N=1 (vs. M. daweimontis Rao & Yang male SVL 34–37 mm, N=17, female SVL 40–46 mm, N=3; M. pachyproctus Huang male SVL 35.3–36.2 mm, N=2, female unknown; M. parva male SVL 33.9–36.0 mm, N=2, female SVL 41.1–41.4 mm, N=2; M. wuliangshanensis Ye & Fei male SVL 27.3–31.6 mm, N=10, female SVL 41.0– 41.5 mm, N=2; M. zunhebotoensis Mathew & Sen male SVL 30.0 mm, N=1, female SVL 39.0 mm, N=1), further from M. daweimontis by HL>HW (vs. HW≥HL), palmar and metatarsal tubercles absent in life and in preservation (vs. inner and outer palmar tubercles and inner metatarsal tubercles distinct and red in life), further from M. pachyproctus by protruding projection posterior to cloaca of male absent (vs. present), and further from M. parva by TYD /ED 49.2–63.2%, N=10 (vs. TYD /ED 40–48.9%, N=4), shanks considerably longer on males, SHL/SVL 46–55.3%, N=8 (vs. male SHL/SVL 42.8–43.7%, N=2); from M. nankiangensis Liu & Hu and M. shapingensis Liu by tympanum clearly defined (vs. tympanum concealed by supratympanic fold); from M. binchuanensis Ye & Fei and M. wushanensis Ye & Fei by subarticular tubercles absent (vs. present), and lateral fringes on toes absent (vs. present); from M. palpebralespinosa Bourret by webbing between toes rudimentary (vs. approx. half digit length); from M. binlingensis Jiang, Fei & Ye and M. minor by lateral fringes on toes absent (vs. present), further from M. binlingensis by vomerine ridges weakly raised and circular (vs. slender and not dilated at its posterior region), and further from M. minor by dark spots on the throat present on most specimens (vs. absent); from M. wawuensis Fei, Jiang & Zheng and M. zhangi Ye & Fei by dorsolateral folds distinct (vs. indistinct), further from M. wawuensis by larger tympanum, TYD /ED 49.2–63.2%, N=10 (vs. TYD /ED ca. 33%), and further from M. zhangi by lateral fringes on toes absent (vs. present); from M. serchhipii Mathew & Sen by dorsolateral folds always present, usually 2/3 to complete body length (vs. absent).
Holotype description (measurements in mm). Mature male (SVL 45.3) (Figures 1, 2A). Head small (HW 14.6, HL 15.6, IFE 7.5, IBE 12.6), longer than wide; snout rounded in dorsal view, obtusely protruding in lateral view, without rostral appendage (Figure 1C); loreal region vertical and concave; canthus rostralis angular; dorsal region of snout slightly concave; eye (EL 5.4) twice as long as maximum tympanum diameter (TYD 2.7) and subequal to snout (SL 5.5); eye-tympanum distance (TYE 2.7) equal to maximum tympanum diameter; tympanum slightly oval, orientated vertically, its upper approx. 5 percent concealed by supratympanic ridge (Figure 1C); pupil in life oval, horizontally orientated when dilated; nostril orientated laterally, closer to eye than snout (EN 2.5, SN 3.4); internarial distance (IN 4.7) subequal to eyelid width (UEW 4.6), and greater than narrowest point between upper eyelids (IUE 4.2); pineal ocellus not visible externally; vomerine ridges present, circular and weakly raised with small vomerine teeth, positioned between choanae, separated from each other by distance equal to distance from choanae; tongue moderately large, weakly notched posteriorly, with no medial lingual process.
Forelimbs moderately long and thin, forearm (FAL 10.3) slightly enlarged relative to upper forelimb, and shorter than hand (HAL 13.1); fingers long and narrow without lateral fringes (Figure 1D), finger length formula I<II<IV<III (FIL 5.2, FIIL 5.7, FIIIL 9.7, FIVL 6.8); interdigital webbing, and subarticular, supernumerary and palmar tubercles absent; thenar tubercle weak; finger tips slightly expanded and flattened to oval pads; terminal grooves absent. Hindlimbs relatively long and thin, shanks overlap when thighs are held at right angle to body; thigh (TL 21.8) shorter than shank (SHL 22.5), and longer than foot (FOL 19.7); toes long and rounded without lateral fringes (Figure 1E), relative toe lengths I<II<V<III<IV; toe tips slightly dilated, with distinct pads; terminal groves absent; base of toes with rudimentary webbing; outer metatarsal tubercle, subarticular and supernumerary tubercles absent; inner metatarsal tubercle very weak; ridge of callous tissue absent on ventral surface of all digits.
Skin of dorsal surfaces of body, limbs, and dorsal and lateral surfaces of head weakly granular; tympanum smooth with its borders slightly raised; small pointed tubercle present on outer edge of upper eyelid; supratympanic fold narrow anteriorly, widening posteriorly, extending from orbit and curving down around upper border of tympanum, terminating above axilla (Figure 1C); flanks with small scattered tubercles; thin dorsolateral fold extending from behind supratympanic fold to approximately two-thirds distance to groin, longer on left side than right; a weak, “V”-shaped parietoscapular ridge present, its two sides extending posteriorly from above tympanum and meeting medially beyond level of axilla; a second inverted “V”-shaped ridge present on mid-dorsum which joins laterally with dorsolateral fold on left side only (Figure 1A); small tubercles arranged into distinct transverse rows on dorsal surface of thighs, shanks and forearms. Gular region, chest and ventral surfaces of limbs smooth; abdomen weakly granular; pectoral glands small, slightly raised, positioned on level with axilla (Figure 1B); femoral glands small, slightly raised, positioned subequally distant from knee and cloaca on posterior surface of thigh; white skin asperities forming narrow band circummarginally on lower jaw; black asperities on tubercles of posterior, and few on anterior half of back and flanks, on dorsal ridges, and tympanic regions, posterior parts of upper eyelids, and less densely on dorsal surfaces of upper forelimbs, thighs and shanks.
Colour in preservative (Figure 1): Entire dorsal and lateral surfaces of head, body, forelimbs and hindlimbs brown; slightly darker brown triangular marking with light central blotch between eyes; dorsolateral and supratympanic folds and flank tubercles brownish-cream; front of snout and lateral canthus rostralis dark brown; wide vertical dark brown bar below eyes and dark brown blotch covering tympanum; two dark brown blotches on anterior lateral surface of forearms; dorsal surface of hands and feet with dark brown spots and speckles. Gular region, chest and anterior part of abdomen primarily dark brown, with white speckling along outer margin of ventral mandibles; dark colouration of chest lightening posteriorly on abdomen which is mottled light and dark brown; ventral surfaces of thighs and shanks with pale brown mottling; ventral surfaces of tarsus and feet dark grey brown; area surrounding vent and posterior surfaces of thighs dark brown; forelimbs ventrally mottled light and dark brown; grey-brown colouration of ventral side of hands extending as a blotch onto ventral surface of forearms; pectoral and femoral glands white. Colour in life (Figure 2A): Dorsally light greyish-brown; dorsal and ventral surfaces with orange speckling, most dense on groin region, on flank tubercles and granules of dorsum, and most noticeable on ventral surfaces where it contrasts with dark grey colouration; ventral surface of throat with feint, dark longitudinal stripes. Iris metallic mid-brown.
Variation. See Table 1 for morphometric characters of eight adult males and two females. Vomerine ridges small to medium-sized. Of the ten examined specimens only the holotype and the two referred specimens (SDB.DU 2009.727 and SDB.DU 2009.730) possess visible, small vomerine teeth. Dorsolateral folds extend approximately 65–100 percent of the body length except on the holotype which possesses one side that extends only ca. 50 percent body length. All specimens have a prominent pointed tubercle on the eyelid except BNHS 5601 on which tubercles are absent, and BNHS 5600 which possesses a tubercle on one side only. Most specimens possess a “V”-shaped parietoscapular ridge and a second inverted “V”-shaped ridge on the mid-dorsum which joins laterally with the dorsolateral folds, except BNHS 5600 and BNHS 5599 which do not possess the mid-dorsal ridge. The presence of dermal asperities on SDB.DU 2009.730, BNHS 5598, and BNHS 5601–5602 is similar to the state observed on the holotype. Dermal asperities on ZSI A 11607, like on the aforementioned specimens but considerably denser. On SDB.DU 2009.727 dorsal asperities are restricted to the posterior half to the back, upper flanks, and tympanic region; on BNHS 5600 asperities on the lower jaw are absent and only sparsely cover the posterior back and hindlimbs. The dark ventral regions on the holotype are lighter grey-brown on some individuals (e.g., ZSI A 11607, SDB.DU 2009.727, SDB.DU 2009.730). BNHS 5598–5602 and ZSI A 11608 have distinct dark longitudinal stripes on the throat, and feint crossbars dorsally on hindlimbs. BNHS 5598–5602, and SDB.DU 2009.730 have barely distinguishable dark brown blotches surrounding the “V” shaped dorsal folds; remaining specimens without distinct dorsal markings. Dorsal colouration in life varies from light to dark brown, with varying density of orange speckling which never predominates the overall colouration (Figure 2B–C).
Secondary sexual characters. Males with slightly raised nuptial pads covered with black micro-granules, covering most of the dorsal surface of the base of finger I, narrowing distally and extending onto the base of the distal phalange on the inner dorsal side; nuptial pad small sized and oval shaped on finger II, only on the inner dorsal side of the base of the digit; external vocal sac distinct on some individuals, and indistinct on others; internal vocal slits present near the rear of the lower mandible; forearms slightly enlarged relative to upper forelimbs; extensive dermal asperities present; protruding fleshy projection posterior to cloaca absent. Female (BNHS 5599) with large unpigmented ova (diameter 1.4–1.7 mm, N=4); both examined females do not possess nuptial pads, enlarged forearms, vocal sac or slits, or any dermal asperities.
Etymology. The specific epithet “ ancrae ” is Latin for “of the valley” as all collection localities for the type series were along the foothills of the Noa-Dihing river valley in Namdapha National Park and Tiger Reserve. Distribution. This species is thus far known only from the type locality and surrounding foothill areas (330– 790 m asl.) in Namdapha National Park and Tiger Reserve in Changlang district of eastern Arunachal Pradesh, northeast India (Figure 3).
Habitat and natural history. The primary habitat type in Namdapha National Park and Tiger Reserve is broadly regarded as tropical lowland evergreen forest (see Proctor et al. 1998, and references therein for further description of forest composition). Megophrys ancrae sp. nov. was found to be relatively abundant at the type locality, however they were quite difficult to locate. ZSI A 11606–11607 were collected from leaf litter on the forest floor. BNHS 5598 was collected from a bush overhanging the Bornulla stream at ca. 3 m above stream level (Figure 4D). All specimens were active and collected between 18:30–19:30 h. The adult female BNHS 5599 was gravid and all males were calling when collected, indicating that the breeding season for this species extends at least between 20th May to 20th July. Bornulla stream is a steep rocky torrent that flows through dense forest habitat with dense undergrowth vegetation.
Remarks. In the past couple of decades the results of only a few herpetological surveys in Namdapha National Park and Tiger Reserve have been published (e.g., Pawar & Birand 2001; Sarkar & Ray 2006; Sarkar & Sanyal 1985). From the Megophryinae subfamily, Pawar and Birand (2001) reported the species Megophrys robusta; a large bodied species which can not be confused with Megophrys ancrae sp. nov. Though these authors mentioned that some specimens from their northeast Indian survey were collected for later identification, they do not provide specimen details, thus their locality reports must be considered anecdotal. Sarkar & Ray (2006) report a single specimen which they identify as Megophrys major, with a brief description stating characters that clearly distinguish it from the species described here, i.e., SVL 67 mm and toes “more or less one fourth webbed”.
A single adult female Megophrys specimen (BMNH 1934.10.2.10) was collected by Captain Kingdon Ward from the Lohit Valley, Sadiya Frontier Tract, and discussed by Smith (1935) under the identification of M. minor. The Lohit River flows through the Lohit and Anjaw districts of Arunachal Pradesh and forms the adjacent major drainage system to the north of that created by the Noa-Dihing river valley. The condition of the specimen is quite dehydrated making determination of soft characters unreliable, however it is not considered to be conspecific with Megophrys ancrae sp. nov. due to small adult female size (SVL 34.5 mm), absence of vomerine ridges, and circular tympanum (Mahony, pers. obs.). Further fresh collections of the Lohit population are necessary to revise Smith’s identification, and thus the verification of M. minor in India.
description: Published as part of Mahony, Stephen, Teeling, Emma C. & Biju, S. D., 2013, Three new species of horned frogs, Megophrys (Amphibia: Megophryidae), from northeast India, with a resolution to the identity of Megophrys boettgeri populations reported from the region, pp. 143-169 in Zootaxa 3722 (2) on pages 145-151, DOI: 10.11646/zootaxa.3722.2.2, http://zenodo.org/record/249321