Ophryophryne gerti Ohler, 2003

Jr., Nikolay A. Poyarkov, Duong, Tang Van, Orlov, Nikolai L., Gogoleva, Svetlana S., Vassilieva, Anna B., Nguyen, Luan Thanh, Nguyen, Vu Dang Hoang, Nguyen, Sang Ngoc, Che, Jing & Mahony, Stephen, 2017, Molecular, morphological and acoustic assessment of the genus Ophryophryne (Anura, Megophryidae) from Langbian Plateau, southern Vietnam, with description of a new species, ZooKeys 672, pp. 49-120 : 56-59

Taxonomic remarks on Ophryophryne gerti Ohler, 2003

Chresonymy:

[?] Ophryophryne microstoma - Orlov et al. 2002:84 ( partim–– Dac Lac [Dak Lak] and Lam Dong provinces, Vietnam; no reffered specimens indicated, inclusion fide N.L. Orlov).

Ophryophryne gerti Ohler 2003:25, fig. 1 ( partim–– BMNH 1921.4.1.324, BMNH 1921.4.1.323).

[?] Ophryophryne gerti - Ohler 2003:25; Stuart et al., 2006:135 (FMNH 252899, FMNH 252901).

[?] Ophryophryne microstoma - Nguyen et al. 2005:15 ( partim––“ Dak Lak and Lam Dong" provinces, Vietnam; following indication by Orlov et al. 2002).

" Ophryophryne sp. 2" - Orlov et al. 2008:82 (Chu Yang Sin N.P., Dak Lak Prov., Vietnam; ZISP 12836-12879).

Ophryophryne gerti - Nguyen et al. 2009:84-85 ( partim––“ Lam Dong (Cam Li, Dran)", Vietnam).

[?] Ophryophryne microstoma - Nguyen et al. 2009:86 ( partim––“ Dak Lak, Lam Dong", Vietnam; based on the record by Orlov et al. 2002).

[?] Ophryophryne gerti - Stuart et al. 2010:40 (eight uncataloged “topotype” females from Bidoup–Nui Ba N.P., Langbian Plateau, Vietnam).

Ophryophryne gerti - Poyarkov [Paiarkov] and Vassilieva 2011:202 ( Bidoup–Nui Ba N.P., Lam Dong Prov., Vietnam; ZMMU A-4715, ZMMU A-4718).

Removed from chresonymy:

Ophryophryne gerti Ohler 2003:25 ( partim–– BMNH “1972.15.2.4” [sic. BMNH 1972.1524])

Ophryophryne gerti - Stuart 2005:475 (FMNH 258564)

Ophryophryne gerti - Bain et al. 2007:108 (AMNH A-169287, AMNH A-163668)

[?] Ophryophryne gerti - Orlov et al. 2015:2010, fig. 9 (Gia Lai Prov., Vietnam; based on identification of the specimen illustrated in fig. 9 as Ophryophryne cf. poilani sensu auctorum).

Holotype.

BMNH 1921.4.1.324, adult male from "Cam Ly (river), south-east of Da Lat (11°56'N; 108°25'E), Lang Bian Plateau, sLam [sic. = Lam] Dong Province, Vietnam", collected by M.A. Smith, presented to BMNH in 1921 ( Ohler 2003; NHMUK specimen catalogue). Re-examined by SM.

Paratypes.

BMNH 1921.4.1.323, immature female from "Dran (11°50'N; 108°34'E), Lang Bian Plateau, Lam Dong Province, Vietnam", collected by M.A. Smith, presented to BMNH in 1921; BMNH 1972.1524 (see ‘Remarks’) adult male, "Huey Sapan, Pak Maat (precise location not found), Mekong, Laos", collector M.A. Smith, accessioned in the BMNH from Smith’s private collection in 1972, collection date unknown ( Ohler 2003; NHMUK specimen catalogue).

Remarks.

Ohler (2003) provides the paratype number BMNH 1972.15.2.4 for the Laos paratype specimen, however, the number on the specimen tag and NHMUK specimen catalogue reads BMNH 1972.1524 ( Mahony 2011b). Our present data suggests that O. gerti is not found beyond the limits of the Langbian Plateau, thus we are confident that the paratype BMNH 1972.1524 does not represent this biological taxon. Ohler (2003: and by implication Stuart et al. 2006) preliminarily identified two specimens from Ankhe Dist. in northern Gia Lai Prov. as O. gerti . This locality is disconnected from the Langbian highlands by a wide lowland area, indicating that these specimens are biogeographically isolated from O. gerti s. stricto. Further work is necessary to ascertain the taxanomic status of these specimens. Orlov et al. (2002), without providing data on examined specimens, considered that the distribution of O. microstoma extended south in Vietnam as far as the Lam Dong and Dak Lak provinces. Our results suggest that these southern Vietnamese populations most likely represented the superficially similar O. gerti , O. synoria , or possibly the new taxon described below. Stuart (2005) reports O. gerti from Champasak Prov. in southern Laos, based on a single specimen (FMNH 258564: not examined here). This locality is biogeographically not connected to the known range of this species, as redefined here, thus the taxonomic status of this specimen requires further confirmation. Bain et al. (2007) identifies two specimens AMNH A-169287 (Thua Thien-Hue Prov., Vietnam) and AMNH A-163668 (Quang Nam Prov., Vietnam) as O. gerti . We re-examined these specimens and regard them to be morphologically more similar to O. poilani . Furthemore, both specimens were included in our molecular analysis and found to be distantly related to O. gerti s. stricto (Fig. 2). Stuart et al. (2010) provides the SVL range (SVL 37.5-42.5 mm, mean ± SD 40.4 ± 1.6, N = 8) for ‘topotype’ female specimens of O. " gerti ", however these specimens are smaller than females of O. gerti provided herein (SVL 43.1-47.4 mm, mean ± SD 45.07 ± 2.16, N = 3), and larger than the new taxon described below (SVL 35.1-36.5 mm, mean ± SD 35.6 ± 0.5, N = 6) (see Table 3 for details). The taxonomic status of these specimens remains unknown.

Vernacular name.

English: “Gerti’s Mountain Toad"; Vietnamese: “Cóc Núi Got" ( Nguyen et al. 2009), “Cóc Núi Goti" ( Nguyen et al. 2014).

Redescription of the holotype.

Mature male (SVL 35.7 mm), habitus slender (Fig. 7A, B). Specimen in good state of preservation; two incisions are present on trunk, one longitudinally orientated on mid-abdomen, another longitudinally oriented on upper flank on right side; liver and testes observable through incisions, testes enlarged; jaw is dislocated on right allowing visual access to buccal cavity.

Head moderately small (HL/SVL 25.5%; HW/SVL 29.7%), wider than long (HW/HL 116.5%), relatively deep; top of head flat; snout comparatively short (SL/HL 33.0%), truncated in dorsal view (Fig. 7A), projecting significantly beyond margin of lower jaw in profile (Fig. 7C); loreal region vertical; canthus rostralis distinct, moderately sharp; dorsal region of snout flat; eyes large (ED/HL 38.5%), slightly protuberant in dorsal view and in profile, horizontal eye diameter less than twice as long as maximum tympanum diameter (TYD/ED 62.9%) and longer than snout (ED/SL 116.7%); eye to tympanum distance approximately equal to maximum tympanum diameter (TYE/TYD 95.5%); tympanum distinct, circular, moderately large (TYD/HL 24.2%); pupil in preservation oval (Fig. 7C), vertically orientated; nostril opening oval, vertical, laterally orientated, medially located between eye and snout (EN/NS 100.0%); internarial distance subequal to upper eyelid width (IN/UEW 103.2%), and significantly less than narrowest point between upper eyelids (IN/IUE 145.5%); pineal ocellus not visible externally; vomerine ridges absent; maxillary and vomerine teeth absent; vocal sac gular, its’ openings not discernable; tongue moderately large, posterior end free, with weak notch posteriorly, lacking medial lingual process.

Forelimbs slender, forearm moderately long (FAL/SVL 22.4%) slightly enlarged relative to upper forelimb, and shorter than hand (FAL/HAL 95.2%); fingers long and narrow, dorsoventrally flattened; lateral fringes and webbing absent (Fig. 7D); finger length formula F1 = F2 <F4 <F3; subarticular tubercles absent, replaced by low callous dermal ridges; supernumerary tubercles absent; outer palmar (metacarpal) tubercle weak, longitudinally oval, elevated but with indistinct borders (Fig. 7D); thenar tubercles weak; finger tips rounded, weakly expanded relative to digit widths (wider than distal-most finger articulation), with circular pads (Fig. 7D); terminal grooves absent.

Hindlimbs slender, relatively long, shanks overlap when thighs are held at right angle to body; shank length less than half of snout to vent length (SHL/SVL 44.5%); thighs shorter than shanks (SHL/TL 106.0%), and feet (FOL/TL 106.4%); toes long and slightly dorsoventrally flattened (Fig. 7E), relative toe lengths T1 <T2 <T5 <T3 <T4; lateral fringes on toes, outer metatarsal tubercle, subarticular and supernumerary tubercles absent; inner metatarsal tubercle well developed with distinct borders, oval-shaped (IMT/FOL 11.3%) (Fig. 7E); weak ridge of callous tissue present on ventral surface of all toes, not continuing onto metatarsus; webbing between digits rudimentary; tarsal fold absent; toe tips not expanded relative to digit widths, with circular pads; terminal grooves absent.

Skin texture and skin glands in preservation.

Skin of dorsal and lateral surfaces of head, body and limbs smooth with numerous small tubercles finely and relatively evenly scattered on dorsal surfaces of trunk, head and limbs (Fig. 7A); small tubercles present on temporal region, tympanum smooth with borders weakly raised; tubercles arranged in distinct transverse ridges on dorsal surfaces of forearms, shanks and thighs; numerous large tubercles on flanks irregularly scattered from axilla to groin, intermixed with smaller tubercles; central portion of outer edge of upper eyelids slightly thickened, with a single short tubercular spine (Fig. 7C), transverse fold on posterior edges of upper eyelids absent; well-developed glandular supratympanic folds, narrow anteriorly, considerably widening posteriorly, from posterior corner of orbits, extending along upper margin of tympanum, terminating above forelimb insertions (Fig. 7C); dorsolateral glandular ridge well-developed, extending from posterior to supratympanic ridges to ca. 75% of trunk length, on each side; a moderately well-developed ">-<" shaped glandular parietoscapular-sacral ridge present on dorsum (see Fig. 7A); two small tubercles present above vent; gular region, chest, and ventral surfaces of limbs smooth to weakly shagreened, abdomen weakly granular; two nuptial pads per limb, one large on dorsal surface of F1 from base of metacarpal to near distal joint, another small pad on inner dorsal surface of F2 on metacarpal; pectoral glands round, weakly raised, positioned level with axilla; femoral glands slightly raised, average size, on posterior surface of thighs, situated slightly closer to knee than to cloaca; numerous small white asperities present on posterior half of dorsum, sparse anteriorly, increasing in density posteriorly to above cloaca, absent from all remaining surfaces.

Color of holotype in preservative

(Figure 7). Dorsal surfaces of head, body, forearms and hindlimbs mid to light brown, slightly lighter on flanks and dorsal surface of upper arms; a distinct darker brown “V” -shaped marking on dorsal surface of head; no distinct “X” -shaped or hourglass marking on mid dorsum; most flank tubercles are bordered below by a small dark brown spot anteriorly, increasing in size posteriorly towards groin; a broad brown stripe extends around lateral surfaces of snout, from anterior borders of orbits between canthus rostralis and the level of lower border of nostrils; two broad darker brown vertical stripes below orbits, one at level of anterior orbital border, and a second extends from central lower border of orbits to edge of jaw, a faint darker brown stripe extends from posterior border of orbits to cover tympanum; color of supratympanic folds same as surrounding sufaces, but lower border dark brown; edge of lower eyelid dark brown; dorsal surfaces of forearms each with two dark brown transverse blotches, and thighs and shanks with faint darker brown transverse stripes; ventral surfaces of throat, chest and anterior half of abdomen, and ventral surface of hands primarily plain light brown, fading to a mottled brownish beige with small dark brown blotches on posterior half of abdomen, and ventral surfaces of forelimbs, thighs and shanks, and dorsal surfaces of tarsi and feet; ventral surface of tarsi and feet dark brown fading distally on toes to a mid-brown; area surrounding cloaca dark brown, fading distally on lateral surfaces of thighs.

Measurements of the holotype

(all in mm, taken by SM).SVL 35.7; HW 10.6; HL 9.1; IFE 5.0; IBE 8.2; ED 3.5; TYD 2.2; TYE 2.1; SL 3.0; EN 1.5; NS 1.5; IUE 2.2; IN 3.2; UEW 3.1; FAL 8.0; HAL 8.4; FIL 3.4; FIIL 3.4; FIIIL 5.6; FIVL 3.6; SHL 15.9; TL 15.0; FOL 14.1; TFOL 21.7; IMT 1.6; TIL 1.7; TIIL 3.8; TIIIL 5.5; TIVL 6.7; TVL 3.5.

Distribution.

Ophryophryne gerti is herein confirmed from three localities on the Langbian Plateau in southern Vietnam, between 700-2000 m a.s.l. (Fig. 1): Cam Ly River and Nui Ba Mt. in environs of Dalat city, Lam Dong Prov., Vietnam (1000-1800 m a.s.l.) ( Ohler 2003, this study); Environs of Bidoup Mt. (2000 m a.s.l.), and Giang Ly Ranger Station (1500 m a.s.l.), Bidoup–Nui Ba N.P., Lam Dong Prov., Vietnam (this study); Chu Yang Sin Mt. environs, Krong Kmar Commune, Krong Bong Dist., Dak Lak Prov., Vietnam (700-2000 m a.s.l.) ( Orlov et al. 2008; this study). Additional localities reported in literature require confirmation pending further study of voucher material (see Remarks section above).