Kalophrynus honbaensis, Vassilieva, Anna B., Galoyan, Eduard A., Gogoleva, Svetlana S. & Poyarkov, Nikolay A., 2014

Vassilieva, Anna B., Galoyan, Eduard A., Gogoleva, Svetlana S. & Poyarkov, Nikolay A., 2014, Two new species of Kalophrynus Tschudi, 1838 (Anura: Microhylidae) from the Annamite mountains in southern Vietnam, Zootaxa 3796 (3), pp. 401-434 : 422-428

Kalophrynus honbaensis sp. nov.

Holotype. ZMMU A- 4941 (field number ABV-00320), adult male from the vicinity of the Yersin station on Hon Ba Mountain, Hon Ba Nature Reserve, Cam Lam District, Khanh Hoa Province, Vietnam (coordinates 12°07' 16" N, 108° 56' 55" E, elevation 1500 m a.s.l.), collected by A.B. Vassilieva on 19 June 2013.

Paratype. ZMMU A- 4943 (field number ABV-00302), adult male collected by A.B. Vassilieva on 16 of June 2013 in the same area with holotype.

Diagnosis. The species is allocated to Kalophrynus based on the following characters considered diagnostic for the genus ( Parker 1934, Bourret 1942, Inger, 1966): one or more transverse dermal ridges across the palate anteriorly to the oesophagus; tips of digits not dilated to disks; no spine-like projections at heel or elbow; snout short, pointed; tympanum visible; pupil horizontal; inner metatarsal tubercle low, not shovel-like; skin thick and glandular. The new species is distinguishable from its congeners by a combination of the following features: (1) SVL 26.7–36.8 mm in males; (2) snout pointed, slightly sloped ventrally; (3) canthus rostralis distinct; (4) males without distinguishable spines on the mandible margins; (5) males without nuptial pads on fingers; (6) tympanum distinct, smaller than eye in diameter; (7) toe webbing moderate; (8) outer metatarsal tubercle present; (9) light dorsolateral line absent; (10) dark ocelli in the inguinal region present, large, without distinct light bordering; (11) anterior palatal dermal ridge on the palate developed, parallel to posterior palatal dermal ridge.

Description of holotype. Adult male ( Fig. 9 AB) with well-developed oblong testes; measurements are given in the Table 4.

Habitus stout, with body widest in lumbar area. Head relatively short (HL/SVL 0.3), wider than long (HL/HW 0.82), triangular. Snout pointed, short, about one third of head length (SL/HL 0.33), sloping in profile ( Fig. 9 C) and distinctly projecting beyond lower jaw; canthus rostralis distinct, finely tuberculate; nostrils rounded, situated closer to snout tip than to eye (SND/ END 0.58) and oriented rostrolaterally. Eyes bulging, medium-sized (ED/SVL 0.11), lateral, well visible from below, with oval horizontal pupil; upper eyelid with prominent tubercles on margin, UEW/IOD 0.43. Tympanum very close to eye, smaller than eye (TD/ED 0.79; TD/SVL 0.09), roughly round, distinct, bordered from above by sharply prominent supratympanic fold running from posterior corner of eye along upper edge of tympanum and then down to the point of forelimb insertion. Maxillary and vomerine teeth absent; tongue with even rounded edge posteriorly; two transversal dermal ridges on palate posterior to eye level, in close proximity and parallel to each other: anterior one smaller and smooth, posterior ridge more prominent and crenulated; postchoanal ridges indistinct. Small notch in the rostral part of skin covering upper jaw and small prominence on the rostral part of lower jaw, fitting together. Single subgular vocal sac; wide slit-like vocal openings between jaw articulation and tongue insertion.

Prominent blunt tubercles on subtympanal and axillar areas and on ventral surface of mandible in its posterior part; some tubercles topped with extremely tiny, microscopic sharp spines, distinguishable only under strong magnification.

Forelimbs slender, more than half of body length (FLL/SVL 0.69); hands with rudimentary webbing. Tips of fingers rounded, without dilatation. Relative length of fingers I<IV<II<III; palmar tubercle moderately large, prominent, oval in shape; subarticular tubercles prominent, rounded; one on each fingers I, II and IV and two on finger III; smaller additional metacarpal tubercles between palmar tubercle and each finger base ( Fig. 10 A).

Hind limbs slender, relatively short (HLL/SVL 1.35); when legs adpressed to body laterally, heel reaches posterior end of tympanum. Tibia slightly shorter than thigh (TFL/ThL 0.95) and significantly shorter than tarsus+foot (TFL/TarFL 0.63). Toe tips rounded, slightly dilated; relative length of toes I<II<V<III<IV; foot webbing formula I 1–2 II 1 ½ –3 III 2–3 ¾ IV 4–2 V; subarticular tubercles moderately prominent on toes I–IV, oval in shape; one on each toe I and II, two on toe III and three on toe IV; distal subarticular tubercle on toe V distinct, proximal rudimentary, almost absent; inner metatarsal tubercle prominent, oval; outer metatarsal tubercle about half the size of the inner (OMTL/IMTL 0.49), low, rounded ( Fig. 10 B).

Skin on dorsum finely shagreened from snout to vent, with singular small rounded tubercles; roughly granular on belly, lower flanks, underside of thighs and the cloacal region; smooth on chest area, inner leg surfaces and forelimbs; finely granular on gular area. About ten asymmetric whitish glandular tubercles on chest. Dorsolateral boundary sharp, glandular, with prominent tubercles.

Coloration. In life ( Fig. 11 AB) ground coloration on dorsal surfaces of head, trunk and limb orange-yellow, unpatterned, with tiny reddish dots on skin tubercles. Inguinal and axillar areas and inner leg surfaces yellow. Lateral surfaces of head and flanks brown, contrasting with dorsal coloration. Faint brownish transversal bands running across thigh, shin, foot and forearm; underside of foot, lower forearm and knee with brown marbled pattern. Cloacal region brownish, separated from dorsal surface by thin pale edging line. Inguinal ocellus represented by large (larger than tympanum, ISD/TD 1.53) rounded, black spot in each inguinal area, with faintly distinct lighter bordering. Venter yellowish-pink, with brown marbled pattern on chest; gular area brownish, darkening to rostral mandible part; palmar surfaces pink, plantar mostly brown. Iris copper-brown.

In preservative coloration fades to grayish-pink on dorsum, dark gray on flanks and yellowish-gray on venter; other features remain without significant change.

Variation. Paratype male is mostly similar to the holotype in morphology and body proportions, but smaller in size ( Table 1 ; Fig. 12 ); microscopic spines on mandible are absent. In life coloration, paler diffuse blotches occur on orange-yellow ground on dorsum; lower belly and thigh undersides display slightly denser marbled pigmentation ( Fig. 11 CD).

Natural history. Both specimens were collected on the ground at night time after rain, on the limited parcel of primary montane polydominant evergreen forest on the top of mountain ridge at elevation ca. 1500 m a.s.l., with the predominance of Fagaceae ( Lithocarpus , Quercus ), Elaeocarpaceae (Elaeocarpus) , Theaceae , Lauraceae , Araliaceae and Rutaceae , and abundance of large granite rocks ( Fig. 13 ), where Kalophrynus honbaensis sp. nov. occurs syntopically with Raorchestes gryllus (Smith) , Hylarana cf. montivaga (Smith) , Leptobrachium leucops Stuart, Rowley, Tran, Le & Hoang , and Ingerophrynus galeatus .

Comparison. In southern Vietnam Kalophrynus honbaensis sp. nov. co-occurs with two congeners: the mostly lowland K. interlineatus , and Kalophrynus cryptophonus sp. nov. From southern Vietnamese K. interlineatus , the new species differs morphologically by following features: smaller body size in males (SVL 26.7–36.8 mm in Kalophrynus honbaensis sp. nov. vs. 38.6–44.5 in K. interlineatus ); finely granular skin on gular area (vs. roughly tuberculated in K. interlineatus ); relatively longer legs (HLL/SVL 1.32±0.04 vs. 1.16± 0.07 in K. interlineatus ), in adpressed leg heel reaching tympanum (not reaching tympanum in K. interlineatus ); inner metatarsal tubercle twice as long as the outer metatarsal tubercle (average OMTL/IMTL 0.5 vs. 0.74 in K. interlineatus ); anterior palatal dermal ridge straight, entire, parallel to posterior palatal ridge (vs. arch-shaped or angular, often with a notable medial gap in K. interlineatus ); single subarticular tubercle on toe V (vs. two in K. interlineatus ); rudimentary webbing on fingers present (absent in K. interlineatus ) and less extensive webbing on toes (webbing formula I 1–2 II 1 ½ –3 III 2–3 ¾ IV 4–2 V vs. I ½ –2 II 1–2 ½ III 1–3 IV 3 ¾– 1 V in K. interlineatus , Fig. 10 CD).

From Kalophrynus cryptophonus sp. nov. the new species differs morphologically by having a larger body size in males (SVL up to 36.8 mm vs. up to 30.4 mm in Kalophrynus cryptophonus sp. nov.); only microscopic spines on head (vs. large skin spines in Kalophrynus cryptophonus sp. nov.), the absence of nuptial pads in males (present in Kalophrynus cryptophonus sp. nov.); having canthus rostralis distinct, sharp (vs. indistinct, smooth in Kalophrynus cryptophonus sp. nov.); well developed anterior palatal dermal ridge (reduced in Kalophrynus cryptophonus sp. nov.), and less extensive webbing on toes (webbing formula I 1–2 II 1 ½ –3 III 2–3 ¾ IV 4–2 V vs. I 1–2 ½ II ½–2½ III 1 ½ –3½ IV 3 ¾–1½ V). In coloration, Kalophrynus honbaensis sp. nov. differs from Kalophrynus cryptophonus sp. nov. by having a black inguinal ocelli being larger than tympanum (ISD/TD 1.47±0.09) vs. smaller than tympanum (ISD/TD 0.77±0.05).

Kalophrynus honbaensis sp. nov. differs from other congeners distributed in Southern Asia, China, the Malay Peninsula and the Malay Archipelago by a number of morphological and coloration features. In particular, Kalophrynus honbaensis sp. nov. differs by having a substantially larger body size (SVL 26.7–36.8 mm in males) than K. barioensis (SVL 17.5–19.8 mm in males), K. bunguranus (SVL 22.2–23.4 mm in males), K. menglienicus (SVL 19.75–23.4 mm), K. nubicola (SVL 14.4–24.4 mm in males), K. robinsoni (SVL 17 mm in males), K. subterrestris (SVL 23 mm in males), and K. stellatus (SVL 24 mm). Additionally, from these species Kalophrynus honbaensis sp. nov. differs by the presence of subarticular tubercles under finger IV and toe V and an outer metatarsal tubercle (absent in K. barioensis and K. nubicola ); spines on back and upper arms absent (vs. present in males K. bunguranus ); moderate webbing on foot (vs. foot webbing absent in K. menglienicus ), normally developed fingers (vs. shortened finger IV in K. nubicola ); spiny nuptial pads absent (vs. present in males K. robinsoni ); anterior palatal dermal ridge straight (vs. angular in K. subterrestris , arched in K. stellatus ); inguinal ocelli present, larger than tympanum (vs. absent in K. nubicola , equal to tympanum in K. stellatus ).

From other congeners Kalophrynus honbaensis sp. nov. differs by the following features: from K. baluensis by having a single black inguinal ocellus on each side of sacrum (vs. one or two yellow ocelli in K. baluensis ); from K. calciphilus by the absence of dentition on the upper jaw (weak dentition present in K. calciphilus ), by having finger IV longer than I (vs. finger IV shorter than I in K. calciphilus ) and by coloration features (black dorsum and chest, white dorsolateral line, red iris in K. calciphilus ); from K. eok by the presence of inguinal spot (absent in K. eok ) and other coloration features (dark interorbital bar and chevron on shoulders in K. eok ); from K. heterochirus by having normally developed fingers (vs. strongly shortened fingers I, II and IV in K. heterochirus ) and one black inguinal spot on each side of sacrum (vs. few large round yellowish-white spots in the lumbar region in K. heterochirus ); from K. intermedius by the presence of inguinal ocelli (absent in K. intermedius ) and moderate webbing on toes (vs. extensive webbing in K. intermedius ); from K. limbooliati by the presence of subarticular tubercles under toe V and outer metatarsal tubercle (absent in K. limbooliati ) and the absence of a light dorsolateral line (present in K. limbooliati ); from K. minusculus by coloration features (brownish black coloration with black banded pattern in K. minusculus ); from K. orangensis by the presence of rudimental webbing on fingers (absent in K. orangensis ); from K. palmatissimus by moderate toe webbing (vs. extensive webbing in K. palmatissimus ); from K. pleurostigma by a smaller body size (SVL 35–50 mm in males K. pleurostigma ) and the absence of nuptial pads on fingers (present in males K. pleurostigma ); from K. punctatus by a slightly larger body size (SVL 22–27 mm in males K. punctatus ), the presence of an outer metatarsal tubercle (absent in K. punctatus ) and relatively larger tympanum (about ¾ of eye diameter vs. ½ of eye diameter in K. punctatus ); from K. tiomanensis by the presence of an outer metatarsal tubercle (absent in K. tiomanensis ) and the absence of dorsal pattern (vs. spotted lower back in K. tiomanensis ); from K. yongi by the absence of a strongly developed humeral spine and nuptial pads (present in males K. yongi ).

Distribution. To date, the new species is known only from the type locality, Hon Ba Mountain, Cam Lam District, Khanh Hoa Province, Vietnam.

Etymology. The species name is a toponymic adjective derived from the name of the type locality of the new species, the Hon Ba Mountain in Khanh Hoa Province.

Recommended vernacular name: The recommended common name in English is Hon Ba sticky frog.

Figures

FIGURE 9. Holotype of Kalophrynus honbaensis sp. nov. (ZMMU A- 4941) in preservative: (A) dorsal view, (B) ventral view, (C) profile view. Scale bar 3 mm. Photo by V. Trounov.

FIGURE 10. Palmar views of the right hand of the holotype Kalophrynus honbaensis sp. nov. (ZMMU A- 4941) (A) and Kalophrynus interlineatus (C), and plantar views of the right foot of the holotype Kalophrynus honbaensis sp. nov. (B) and Kalophrynus interlineatus (D) in preservative. Scale bar 3 mm. Photo by V. Trounov.

FIGURE 11. Holotype of Kalophrynus honbaensis sp. nov. (ZMMU A- 4941) in life: (A) dorsolateral view, (B) ventral view; male Kalophrynus honbaensis sp. nov. (paratype ZMMU A- 4943) in life: (C) dorsolateral view, (D) ventral view. Photo by V. Trounov.

FIGURE 12. Male Kalophrynus honbaensis sp. nov. (paratype ZMMU A- 4943) in preservative: (A) dorsolateral view, (B) ventral view. Photo by V. Trounov.

FIGURE 13. Natural habitat of Kalophrynus honbaensis sp. nov. in Hon Ba Nature Reserve, Khanh Hoa Province. Photo by A. Vassilieva.