Megophrys (Panophrys) kuatunensis Pope, 1929

Tapley, Benjamin, Cutajar, Timothy, Mahony, Stephen, Nguyen, Chung Thanh, Dau, Vinh Quang, Nguyen, Tao Thien, Luong, Hao Van & Rowley, Jodi J. L., 2017, The Vietnamese population of Megophrys kuatunensis (Amphibia: Megophryidae) represents a new species of Asian horned frog from Vietnam and southern China, Zootaxa 4344 (3), pp. 465-492 : 482-486

Megophrys (Panophrys) kuatunensis Pope, 1929

Figs. 8 & 9 ; Table 5.

Megalophrys kuatunensis Pope 1929:1 (partim: see Remarks section).

–– Megophrys kuatunensis Gee & Boring 1929:20 .

–– Megophrys (Megophrys) kuatunensis Dubois 1980:472 .

–– Panophrys kuatunensis Rao and Yang 1997:98 .

–– Xenophrys kuatunensis Delorme et al. 2006:17 .

–– Megophrys (Panophrys) kuatunensis Mahony et al. 2017:755 .

Holotype: Adult male (AMNH 30126), type locality: “Kuatun [Village], Chungan Hsien, northwest Fukien Province, China, 5500–6000 feet.” (=Guadun [ca. 27°40’N, 117°40’E, ca. 1675–1830 m asl], Wuyishan County, Nanping Prefecture, Fujian Province), collected by Clifford H. Pope, April–September 1926 ( Pope 1929, 1931).

Paratypes: AMNH 30123–30124; AMNH 30239–30258, FMNH 24406 (formerly AMNH 30230), FMNH 24408 (formerly AMNH 30232), FMNH 24411–24413 (formerly AMNH 30235–30237), BMNH 1961.956 (formerly AMNH 30238, then FMNH 24414), BMNH 1985.1294 (formerly AMNH 30234, then FMNH 24410), BMNH 1985.1295 (formerly AMNH 30231, then FMNH 24407), MCZ 28297 (formerly AMNH 30233, then FMNH 24409).

Examined specimens: Full morphological datasets were taken for five adult males, holotype and paratypes ( AMNH 30126, 30240–30241, 30243–30244), and four adult female paratypes ( AMNH 30242, BMNH 1961.956, BMNH 1985.1295, FMNH 24411). SVL measurements were taken for three additional adult male paratypes ( FMNH 24406, FMNH 24412–24413).

Holotype description: ( Figs. 8 & 9 ; Table 5 for measurements): Sexually mature adult male. Head moderately small, width subequal to length; snout rounded in dorsal view, obtusely protruding in lateral view, without rostral appendage ( Fig. 8 ); loreal region vertical and weakly concave; canthus rostralis angular; dorsal region of snout slightly concave; eye diameter greater than three times as long as maximum tympanum diameter, and longer than snout; eye-tympanum distance subequal to maximum tympanum diameter; tympanum circular, its upper edge not concealed by supratympanic ridge ( Fig. 8 ); nostril orientated laterally, closer to eye than snout; internarial distance greater than eyelid width, and subequal to narrowest point between upper eyelids; pineal ocellus not visible externally; vomerine ridges and vomerine teeth absent; tongue moderately large, weakly notched posteriorly, with no medial lingual process.

Forelimbs moderately short and thin, forearm moderately enlarged relative to upper forelimb, and shorter than hand; fingers short and narrow without lateral fringes ( Fig. 9B ), finger length formula IV <I <II <III; interdigital webbing and supernumerary tubercles absent; subarticular tubercles on Fingers I and II only; thenar and outer palmar tubercles weak; finger tips rounded, narrower than adjoining end of distal phalanges; pads on finger tips and terminal grooves absent. Hindlimbs relatively short and thin, shanks overlap when thighs are held at right angle to body; thigh shorter than shank and foot; toes long and rounded without lateral fringes ( Fig. 9 ), relative toe lengths I <II <V <III <IV; toe tips rounded, narrower than adjoining end of distal phalanges, with weakly discernible pads; terminal groves absent; webbing, outer metatarsal tubercle, subarticular and supernumerary tubercles absent; inner metatarsal tubercle weak; ridge of callous tissue on ventral surface of digits absent.

Skin of dorsal, lateral and ventral surfaces of head, body and limbs primarily smooth; tympanum smooth with borders not raised; outer edge of upper eyelid with a short weak ridge; supratympanic fold narrow anteriorly, thick and glandular posteriorly, extending from orbit and sloping down along upper portion of tympanum, where it curves abruptly down, terminating above forearm insertion ( Fig. 8A ); flanks with distinct patches of glandular skin which may have represented tubercles when the specimen was freshly preserved; dorsolateral folds and other dorsal ridges indistinct ( Fig. 8A ); pectoral glands tiny, flat, positioned on level slightly posterior to axilla ( Fig. 8B ); femoral gland small, slightly raised, positioned subequally distant from knees and cloaca on posterior surface of each thigh; dermal asperities absent on all surfaces.

Colouration in preservative: ( Figs. 8 & 9 ): Dorsal and lateral surfaces of head, body, forelimbs and hindlimbs primarily mid-brown; solid dark brown triangular marking on dorsal surface of head between eyes; a dark brown “X”-shaped marking on dorsum, with scattered dark brown spots and blotches on dorsum around “X”- shaped marking and on dorsal surface of snout; front of snout, lateral canthus rostralis and lower half of supratympanic folds dark brown; wide vertical dark brown bar below eyes; dark brown blotch covering tympanum present; a short longitudinal dark brown stripe on central dorsum of snout; two dark brown crossbars on dorsal surface of forearms; dorsal surface of outer three fingers with dark brown transverse blotches; dorsal surface of hindlimbs with large dark brown transverse crossbars, two on thighs, one on shank, and one on tarsus, with dorsal surfaces of feet spotted. Ventral surfaces of head, body and limbs primarily light brown, with dark brown blotches along outer margin of ventral mandibles, gular region, chest and abdomen; a longitudinal dark brown blotch positioned medially, extending from the posterior gular region onto chest; a dark brown stripe extends laterally from the rear of the mandible, over the pectoral region and ventral proximal surface of forelimbs to approximately 70% distance to groin on both sides; ventral surfaces of thighs and shanks without markings; ventral surfaces of tarsus and feet dark brown; area surrounding vent and posterior surfaces of thighs dark brown; ventral surfaces of hands plain grey-brown and forearms ventrally with large dark brown blotch.

Colouration in life: Not recorded.

Variation: Refer to Table 5 for morphometric variation for five adult males and four adult females. Adult male SVL for eight paratypes ranges from 28.3 to 31.4 mm. Finger length formula varied slightly, IV Ĺ I <II <III. Outer palmar, thenar and outer metatarsal tubercles are more distinct on all examined paratypes. Dorsal and lateral surfaces of the head and body of examined paratypes with scattered granules and small tubercles, indicating that the smoothness of the holotype is most likely an artifact of preservation condition. Subarticular tubercles are not distinct on the base of fingers on FMNH 24411, but appear to be present on the base of all fingers on BMNH 1985.1295. No visible notch on the posterior edge of the tongue of AMNH 30242, but this may be an anomaly of preservation. Dorsolateral folds are indistinct on the holotype and some paratypes (AMNH 30240, AMNH 30242, FMNH 24411), weakly developed and on anterior third to half of trunk length on both sides on AMNH 30241 and AMNH 30243, anterior half of trunk length on the left side only on BMNH 1985.1295, narrow and moderately to strongly developed on the anterior three quarters of the trunk length on AMNH 30244 and BMNH 1961.956, or represented by a weak row of tubercles on FMNH 24406. Supratympanic folds do not obscure the tympanum rim on all specimens except AMNH 30244 and BMNH 1961.956, on which the upper margins are covered. AMNH 30240, AMNH 30241 and BMNH 1985.1295 have outer upper eyelids slightly thickened medially, and BMNH 1961.956 has a short raised transverse fold medially, extending to the outer edge of the upper eyelids, but no specimens have distinctly pointed tubercle/s on the upper eyelids. Pectoral glands are visible on all examined paratypes, small, and situated approximately level with the axilla. Femoral glands vary from comparatively small to moderately large in size. Dorsal ridges vary from indistinct on the holotype and paratype FMNH 24411, to moderately well developed (i.e., on AMNH 30240, AMNH 30243, BMNH 1985.1295), with the following configurations observed on examined specimens: parietoscapular ridge only (“>”), parietoscapular-middorsal ridge (“>–”), complete parietoscapular-sacral ridge (“>-<“), or separate parietoscapular and sacral ridges (“> <“). The holotype is the only male with no dermal asperities. AMNH 30240 has small white spinular dermal asperities sparsely distributed on tops of tubercles and on the parietoscapular fold on the anterior dorsum, becoming moderately dense posteriorly; on AMNH 30241, asperities are visible from approximately mid trunk length, increasingly in density posteriorly; on AMNH 30242 and AMNH 30243, asperities are sparse on the tympanic region and on posterior lateral surfaces of head and anterior lateral dorsum, sparse on anterior central dorsum but from mid dorsum increases in density posteriorly. Asperities are absent from all remaining surfaces on these specimens. FMNH 204411 is the only female with dermal asperities with just a few scattered on the posterior dorsum. Colouration in preservation of examined paratypes differed from holotype based on the following characters: triangular marking between the eyes had a light central spot on AMNH 30243 and AMNH 30244; dark brown dorsolateral stripe is present on AMNH 30244; AMNH 30240, AMNH 30241 and AMNH 30243 have two to three transverse crossbars on shanks; palmar, thenar and inner metatarsal tubercles distinctly lighter than surrounding surfaces on paratypes; dark brown blotches on gular region, chest and abdomen vary in intensity and density from almost absent on AMNH 30240 to mottled on AMNH 30241; pectoral and femoral glands noticeably lighter than surrounding surfaces on all examined paratypes; ventral surfaces of thighs and shanks faintly mottled on AMNH 30240, AMNH 30241 and AMNH 30244.

Secondary sexual characters: Males: weakly raised nuptial pads present, appearing smooth and translucent, or covered with brown microspinules, covering most of the dorsal surface of Finger I, narrowing distally and extending to the base of the distal phalange; nuptial pad absent on Finger II; vocal sac indistinct in preservation; internal vocal slits present near the rear of the mandible; forearms slightly to moderately enlarged relative to the upper forelimbs. Females: mature ova without pigmented poles; nuptial pads, internal vocal slits and enlarged forearms absent.

Distribution ( Fig. 10 ): To our knowledge, the presence of M. kuatunensis has only been positively confirmed with molecular data in Fujian and Jiangxi provinces ( Li et al. 2014; Wang et al. 2014; Chen et al. 2017). The IUCN Red List assessment for this species indicates a much wider distribution ( Huiqing et al. 2004) including locations in Zhejiang, Hunan and Guangxi provinces. Geological barriers exist between these locations that may limit the dispersal of Megophrys . The identity of populations assigned to M. kuatunensis in Zhejiang, Hunan and Guangxi provinces should be confirmed with molecular data.

Remarks: Pope (1929) provided a relatively detailed description of the holotype of his new species, M. kuatunensis , including a brief comparison with M. boettgeri and M. minor . He later expanded on this description providing a figure of the holotype, a detailed variation section, and morphological and biological comparison with the sympatric M. boettgeri ( Pope 1931) . The type series of Megophrys kuatunensis was based on the holotype and 31 paratypes ( Pope 1929). Pope (1931:445) included an additional specimen as a paratype, AMNH 30324, stating that “An additional specimen has been found since the appearance of the original description which listed only 31 paratypes ”. This action does not validate AMNH 30324 as a paratype, and thus this specimen is not available for lectotype designation in the future should the holotype become lost/destroyed (International Commission of Zoological Nomenclature 1999). Within the section titled “Notes on paratypes ”, Pope (1929) includes a statement that “Tadpoles were secured”, neither designating a museum number, nor counting them among the 31 specimens referred to directly as paratypes, indicating that Pope did not intend to regard these tadpoles as paratypes. Pope (1931) further comments that of the two series of tadpoles (AMNH 30606 and AMNH 30645) collected from the type locality, he would only tentatively assign the former to M. kuatunensis . These tadpoles should not be considered to be paratypes of M. kuatunensis . Marx (1958) lists three paratypes in the CNHM (FMNH 24408, 24412, 24413), omitting two paratypes FMNH 24406 (formerly AMNH 30230) and FMNH 24411 (formerly AMNH 30235) from his annotated catalogue of type specimens in the collection. This omission was not amended in supplementary catalogue of FMNH types ( Marx 1976), however, we confirm that both of these specimens were present in the collection during a recent visit (S. Mahony, pers. com.).

In their description of a new species, M. brachykolos, Inger and Romer (1961) examined part of the type series of M. kuatunensis and were the first to note that the paratype series of M. kuatunensis is heterogeneous in species composition. They identified a M. kuatunensis female paratype FMNH (as CNHM) 24408 as M. brachykolos on the basis of several measurements and characters that fell within the variation range of the female M. brachykolos types. They designated this specimen as a paratype of their new species ( Inger and Romer 1961; Marx 1976). Our examination of approximately half of the type series of M. kuatunensis (including FMNH 24408) revealed two additional paratypes (AMNH 30239 and BMNH 1985.1294 [formerly AMNH 30234, then FMNH 24410]) that are morphologically conspecific with FMNH 24408, and not M. kuatunensis sensu stricto. Though we partially agree with Inger and Romer (1961) in so far as these specimens share superficial similarities with M. brachykolos sensu stricto (and its sister taxon M. acuta ), we suggest that their identification should be considered tentative pending further study of this population due to geographic distance from the type locality of M. brachykolos , and the recognition of extensive cryptic diversity in Megophrys ( Chen et al. 2017; Mahony et al. 2017).

Figures

FIGURE 8. Adult male Megophrys kuatunensis holotype, AMNH 30126. (A) Dorsal view, and (B) ventral view. Scale bar 10.0 mm.

FIGURE 9. Adult male Megophrys kuatunensis holotype, AMNH 30126. (A) Palmar surface of right hand, and (B) plantar surface of right foot. Scale bar 5.0 mm.

FIGURE 10. Distribution of Megophrys kuatunensis after Huiqing et al. 2004. Blue polygons represent the elevational range of the species; 430 – 1950 m asl within the distributional range reported by the IUCN. Star denotes type locality and black circles denote the locations where M. kuatunenis have been confirmed with molecular data.