Leptolalax (Lalos) aereus Rowley, Stuart, Richards, Phimmachak & Sivongxay, 2010

Ohler, Annemarie, Wollenberg, Katharina C., Grosjean, Stéphane, Hendrix, Ralf, Vences, Miguel, Ziegler, Thomas & Dubois, Alain, 2011, Sorting out Lalos: description of new species and additional taxonomic data on megophryid frogs from northern Indochina (genus Leptolalax, Megophryidae, Anura) 3147, Zootaxa 3147 (1), pp. 1-83 : 56-62

Leptolalax (Lalos) aereus Rowley, Stuart, Richards, Phimmachak & Sivongxay, 2010

( Fig. 23 , 25–29 )

Leptolalax pelodytoides — Ziegler 2002: 47–50.

Leptolalax sp. — Ziegler et al. 2004: 22–23.

Leptolalax cf. pelodytoides — Ziegler et al. 2006: 261. — Hendrix et al. 2008: 27. — Ziegler & Vu 2009: 121.

Leptolalax aereus Rowley, Stuart, Richards, Phimmachak & Sivongxay, 2010c: 36 .

Onymophoront, by original designation: holophoront (holotype) SAMA R 64236, adult male, collected on 23 November 2008 by B. L. Stuart, S. J. Richards, S. Phimmachak and N. Sivongxay .

Onymotope: Rocky stream in semi-evergreen forest in Sepon Mining Tenement (16.96317º N, 106.0466º E, 326 m), Vilabouli District , Savannakhet Province, Laos .

Other protaxonts (paratypes): NCSM 76038–76057 , NCSM 76061–76071 , SAMA R64234–64235 , SAMA R64238–63242 . Collection data see Rowley et al. (2010c) .

Specimens referred to the form 1: Vietnam. Quang Binh Province, Phong Nha – Ke Bang , nearby mountain stream (400–500 m a.s.l.): ZMFK 71346 , adult male, SVL 29.8 mm, collected by Thomas Ziegler, 3 September 1998 ; ZFMK 71341 , 4 tadpoles, coll. T. Ziegler, 3 September 1998 ; — Phong Nha – Ke Bang NP: small stream above a “Waterfall”, 30 m next to Route 20 (km 6) near border: ZFMK 86362 , juvenile, 17 June 2006 ; — stream downhill from Ho Chi Minh Highway (km 54) in U Bo (530 m a.s.l.): RH06149 ( PNNP), juvenile, 30 July 2006 ; — pond next to Ho Chi Minh Highway at km 51: ZFMK 87012–16 , 5 tadpoles, 20 June 2006 ; — stream downhill from Ho Chi Minh Highway (km 54) in U Bo (500 m a.s.l.): ZFMK 87017–19 , 3 tadpoles, 30 July 2006 .

Specimens referred to form 2. Vietnam. Ha Tinh Province: ZMFK 79861 ( TZ 819 ), subadult male, 3 September 1997 , coll. T. Ziegler , locality at 360 m a.s.l; — Quang Binh Province: 50 m below a small mountain stream in Cha Noi: ZFMK 86393 , juvenile, 5 August 2006 ; — river bed below the mountain stream: RH06166 ( PNNP), juvenile, 6 August 2006 ; — river bed below the mountain stream in Cha Noi : RH06167 ( VNUH), adult male, 7 August 2006 ; ZFMK 86394 , adult female, 5 August 2006 ; — mountain stream in Cha Noi : RH06172 ( VNUH), imago, 7 August 2006 ; ZFMK 87009 , 9 tadpoles, 5 August 2006 ; ZFMK 87010 , 6 tadpoles, 7 August 2006 .

Specimens referred to L. aereus , without genetic identification. Vietnam. Ha Tinh Province: MNHN 2010.1040 – 1045 , 6 tadpoles, 11 July 1997, coll. T. Ziegler; — locality at 160 m a.s.l; MNHN 2010.1037 – 1039 , 3 tadpoles, 24 August 1997; — 160 m a.s.l., coll. T. Ziegler ; — Quang Binh Province: Phong Nha – Ke Bang , nearby mountain stream (400–500 m a.s.l.): ZFMK 71347 , adult male, September 1998, coll. T. Ziegler ; — Phong Nha – Ke Bang , Cha Noi : MNHN 2005.0235 , young female, 1 July 2004, coll. T. Ziegler; — mountain stream in Cha Noi: ZFMK 87011 , 4 tadpoles, 10 August 2006; — Phong Nha – Ke Bang National Park : PNNP0022 , 0031 , 0048 , 0040 , one without label, 4 males, 1 female, coll. Dang Ngoc Kien et al. — Nghe An Province: Tuong Duong District: Nga My Commune: Pu Huong Nature Reserve (19°21’385N, 104°52’552E, 380 m a.s.l.): PHO8 007, PHO8 008, 2 males, 26 March 2008, coll. Hoang Ngoc Thao and Dau Quang Vinh.

Comment. The specimens studied by us and allocated to L. aereus form a well supported clade with two subclades, with good support but weak differentiation between these sister clades. In the following text the specimens, depending on their situation in the subclades, are allocated to “form 1” or “form 2”. Note that according to preliminary data (see molecular results above), the original series of L. aereus forms a third genetic lineage. The adults and juveniles belonging to the two forms included here show a low differentiation in morphology and coloration, but the tadpoles can be distinguished by morphology (see details below). We chose to describe these two tadpole forms independently as “form 1” and “form 2” because it is uncertain whether L. aereus as here defined might in fact be a species complex.

Diagnosis. Member of the subgenus Lalos based on the presence of lateroventral glands and molecular phylogenetic relationships ( Fig. 4 ), distinguished from other species included in this subgenus by the following combination of characters: moderate–sized species (males 29.8 mm) ( Table 3) with rudimentary webbing and narrow fringes on toes; tympanum distinct; dermal ridges under toes distinct; finger tips enlarged; dorsal skin granular (Table 4); dorsal pattern showing dark markings and light speckling; few small black and white spots on flanks, ventral side whitish with indistinct brown vermiculation; iris yellowish orange ( Table 5).

Description of the reference specimen ZMFK 71346. Size and general aspect: (1) Specimen of rather large size (SVL 29.8 mm), body rather stout.

Head. (2) Head of medium size, narrower (HW 10.0 mm) than long (HL 11.5 mm; MN 10.0 mm; MFE 7.9 mm; MBE 3.1 mm), flat. (3) Snout protruding, its length (SL 4.6 mm) shorter than horizontal diameter of eye (EL 4.9 mm). (4) Canthus rostralis rounded, loreal region concave, rather vertical. (5) Interorbital space flat, larger (IUE 3.6 mm) than upper eyelid (UEW 3.4 mm) and than internarial distance (IN 2.9 mm); distance between front of eyes (IFE 5.2 mm) about half of the distance between back of eyes (IBE 9.2 mm). (6) Nostrils oval, as close to eye (EN 2.1 mm) as to tip of snout (NS 2.1 mm). (8) Tympanum (TYD 2.3 mm) distinct, oval, horizontal; about half of eye diameter, tympanum-eye distance (TYE 1.0 mm) less than half its diameter. (11) Tongue large, cordate, emarginate.

Forelimbs. (12) Forearm rather long, thin (FLL 8.5 mm), longer than hand (HAL 8.1 mm), not enlarged. (13) Fingers long and thin (TFL 4.6 mm). (15) Tips of fingers rounded, slightly enlarged. (16) Finger II with narrow dermal fringe.

Hindlimbs. (19) Shanks about three times longer (TL 14.5 mm) than wide (TW 4.02 mm), longer than thigh (FL 13.5 mm) and than distance from base of internal metatarsal tubercle to tip of toe IV (FOL 13.9 mm). (20) Toe IV (FTL 7.5 mm) about one-third of distance from base of tarsus to tip of toe IV (TFOL 22.1 mm). (22) Tips of toes rounded, not enlarged. (23) Webbing present, rudimentary, narrow fringes on toes: I 2 – 2 ⅓ II 1 ½ – 3 III 2 ½ – 4 IV 4 ¼ – 2 ½ V (MTTF 5.3 mm; MTFF 5.1 mm; TFTF 8.0 mm; FFTF 9.0 mm). (24) Fringe along toes narrow. (26) Inner metatarsal tubercle rather long, prominent; its length (IMT 1.7 mm) 1.7 times in length of toe I (ITL 2.9 mm).

Skin. (29) Dorsal and lateral parts of head and body: snout, region between eyes, side of head and back granular; flanks with small glandular warts, more densely set on lower part of flanks. (30) Supratympanic fold distinct, from eye to above upper forelimb. (31) Dorsal parts of limbs: smooth with few granules. (32) Ventral parts of head, body and limbs: throat, chest and belly smooth; thigh with a few glandular warts. (33) Presence of macroglands: lateroventral gland present, formed by a few relatively large glands positioned in line; oval, relatively large-sized femoral and axillary glands and round smaller suprabrachial glands.

Coloration. In alcohol: (34) Dorsal and lateral parts of head and body: Grey brown with a dark brown interorbital band and a W-like spot and light grey spots on shoulders; two dark brown spots on rear part of back; lower part of flanks light greyish brown with white and dark brown spots; loreal region light grey brown; tympanic region whitish grey with blackish line below tympanic fold; tympanum light brown; upper lip greyish white with brown spots. (35) Dorsal parts of limbs: light brown with darker brown crossbands; posterior part of thigh brown with white dots corresponding to glands. (36) Ventral parts of head, body and limbs: throat yellowish white; margin of throat brown with white dots; chest and belly white with indistinct brown vermiculation, mainly laterally; thigh brown with white dots corresponding to glands; webbing brown; macroglands white.

In life (form 1). Based both on specimens collected by TZ and RH. Iris of eye gold copper. Dorsum greyish brown to reddish brown. Upper part of forearms lighter, yellowish to orange-brown. Lower part of forelimbs and hindlimbs completely with dark transversal bars. Upper lip with dark bars, with most prominent being under eye. A more or less distinct dark stripe underlining tympanic fold, tympanum in part dark. Suprabrachial gland cream to yellow, may be surrounded by dark. Dark triangle-shaped pattern between eyes, pointing backwards, followed by an equally backwards-pointing dark V-shaped structure that may be surrounded by cream. Another dark transversal element visible in rear part of dorsum, as well as dark blotches towards flanks. Flanks lighter with some light blotches, more or less distinctly surrounded by dark. Venter light, with small light blotches, some surrounded by dark in jaw region. Underside of fore and hindlimbs somewhat darker with small light blotches in rear region.

Male secondary sexual characters: (38) Vocal sacs externally not differentiated; openings present, rounded, positioned posterior on side mouth floor.

Variation. Female sexual characters of forms 1 and 2 of this species are unknown as no adult female was collected although female morphology is known from the accounts of Rowley et al. (2010c). Variation in the following only refers to our own data (of forms 1 to 2) and not to the series studied by Rowley et al. (2010c) in the original description. Young and adults of Leptolalax aereus were collected from several localities at several dates. They are not of the same ontogenetic stage as some have reached adult stage whereas the others are only subadults or young. They differ slightly in dorsal and ventral coloration when preserved in alcohol: specimens of form 1, which includes the described reference specimen, are brown grey on back and light beige on ventral side with darker edges; the glands are white. Specimens of form 2 are light brown grey on back and creamy white on belly, with greyish beige on sides. Another sample collected and deposited in Phong Nha-Ke Bang NP is brown orange on the dorsum and whitish on the ventral side. Specimens of a series from Nghe An Province are dark brown with white belly. The difference between these series is more in the shade of coloration than in the colour pattern as in both form 1 and 2, specimens have a W-shaped pattern in shoulder region and an inverted V-shaped pattern on posterior part of back. In some specimens of either form a dark interoccular band is visible. All specimens have distinct crossbands on forearms, shank, thigh and foot. All show numerous dark spots on flanks. Variation is not only between the two forms but also within the forms. Among specimens of form 2, specimen ZMFK 79861 is unique in having broad greyish white outlines in interorbital and shoulder spots. Form 2 has a generally very distinct colour pattern including W-shaped shoulder spots. In form 1, the two adult frogs (ZFMK 71346–71347) and two just metamorphosed young have a more uniformly coloured dorsum. Ventral colour is uniformly whitish in all specimens but in the two adults which have slightly brownish throats and sides of belly covered with rather dense brown mottling.

Description of the tadpole of Leptolalax aereus form 1. The results of the molecular analysis were also reflected in the allocation of tadpoles to the corresponding adults. The comparison of the uncorrected p-distances of DNA vouchers of the lineage described above as L. aereus showed a similarity of 99.1–99.4 % between tadpoles (ZFMK 87009, ZFMK 87010) and syntopic adults (VNUH uncatalogued: field number RH06167, RH06172) collected in Cha Noi, Quang Binh Province and the adult specimen (ZMFK 79861; field number TZ 819) from Ky Anh – Ke Go, Ha Tinh Province. The tadpoles (ZFMK 87012, ZFMK 87016–87017, ZFMK 87019) from U Bo matched the syntopic juvenile (PNNP uncatalogued: field number RH06149) and the subadult and adult specimens (ZFMK 86362, ZFMK 71346) from nearby areas by a congruence of 100 %. However, the genetic comparison revealed constant and notable differences of 2.4 % between sampled specimens from the northern area (Cha Noi, PNKB, Quang Binh Province and Ky Anh – Ke Go, Ha Tinh Province) and the eastern and southeastern area of Phong Nha − Ke Bang (Waterfall and U Bo).

The external morphology is based on a specimen in stage 34 (from batch ZFMK 87012; includes field numbers RH06019, RH06035; TOL 59.3 mm and BL 16.9 mm).

In dorsal view ( Fig. 28A ), body elliptical elongate. In lateral view, ( Fig. 28B ), BW 138 % of BH, highest in the middle of the abdomen. Eyes moderately sized, ED 9.6 % of BL, bulging. Nares elliptical, moderately sized, RN 53 % of NP; NN 72 % of PP. Spiracle flattened tubular, positioned laterally, SS 52 % of BL, oriented slightly more posteriorly than posterodorsally; its opening directed posterodorsally, situated on an axis which should go through the apex of myotomes of caudal muscle. Tail long, TAL 249 % of BL; tail musculature, TMH 83 % of BH and 59 % of MTH, TMW 63 % BW, the lower part slightly bulging in the proximal third. UF 33 % of MTH, LF 26 % of MTH, SU 113 % of BL, upper fin almost nonexistent in its first third then increasing rather abruptly; point of maximum height of tail located at its first third, MTH 142 % of BH. Anal tube moderately sized. Lateral line identical to L. bourreti .

Oral disc ( Fig. 28C ) moderately sized, ODW 21 % of BL and 40 % of BW. Marginal papillae fine, conical and pointed; three submarginal papillae on each side in front of the extremities of the rows P2 to P4. No denticulate papillae. KRF 1:4+4/3+2:1, A4> A5> A3> A2 >> A1; P2> P1 = P3> P4; A1 about one-third of P4, P4 more than half of P3. Details of keratodonts not studied. Jaw sheaths black; lower sheath hidden, deeply fitted under the upper jaw sheath.

The coloration in life of L. aereus form 1 extensively corresponds to that of L. aereus form 2 but golden pigmentation is more distinct in form 1. In preservative, upper part of body uniformly brown. Flank (occupied by the lymphatic sacs) from brown in the upper part to grey in the lower part in gradation. Ventral side dirty white. Each lobe of nares tinted in grey in its central part. Caudal muscle beige on slightly more than its half, the rest grey, covered with densely arranged small dots of melanophores leaving some small immaculate areas; these small dots more numerous in the distal part of the muscle; the whole muscle speckled, but the spots more distinct in the proximal half. Fins translucent grey with the same spots and dots than on the caudal muscle, more dense on the upper fin, beginning from the distal half on lower fin and from the proximal third on upper fin.

The description of tadpole variation is based on 10 other specimens, except when noted (stages 25–38, TOL 22.6–47.5 mm (n = 5) and BL 10.8–18.5 mm). Only the ratio values different from those of the described specimen are given: BW 119–136 % of BH; ED 8.2–10.5 % of BL; RN 42–55 % of NP; NN 61–75 % of PP; SS 46–51 % of BL; TAL 193–256 % of BL (n = 5); TMH 60–85 % of BH; TMH 61–69 % of MTH (n = 8); TMW 60–93 % of BW (n = 9); UF 30–32 % of MTH (n = 4); SU 109–143 % of BL (n = 4); LF 23–27 % of MTH (n = 4); MTH 87–129 % of BH (n = 8); ODW 18–26 % of BL; ODW 35–45 % of BW. More the tadpoles are in advanced stages, more their upper fins begin close to body end. The KRF vary from 1:3+3/2+2:1 to 1:5+5/3+3:1 without obvious addition pattern of keratodont rows through ontogeny (1:3+3/2+2:1 one stage 26; 1:3+3/3+3:1 one stage 31; 1:4+4/2+3:1 one stage 25 and one stage 34; 1:4+4/3+3:1 one stage 28, one stage 29, one stage 33, and two stages 35; 1:5+5/2+2:1 one stage 36; 1:5+5/3+3:1 one stage 38); certain specimens have denticulate papillae.

Description of the tadpole of Leptolalax aereus form 2. The external morphology is based on a specimen in stage 26 (from batch ZFMK 87009 includes field numbers RH06161 and RH06164; TOL 43.7 mm and BL 12.9 mm).

In dorsal view ( Fig. 29A ), body elliptical elongate, widest just after the spiracle. In lateral view ( Fig. 29B ), BW 137 % of BH. Eyes bulging, ED 8.9 % of BL. Nares elliptical, moderately-sized, RN 50 % of NP; NN 77 % of PP. Spiracle flattened rectangular, positioned laterally, SS 53 % of BL, oriented at an angle of 30° with the horizontal; its opening directed posteriorly, situated on an axis which should go through the apex of myotomes of the caudal muscle. Tail long, TAL 235 % of BL; tail musculature, TMH 72 % of BH and 59 % of MTH, TMW 57 % of BW, the lower part slightly bulging in its proximal third. Upper fin, UF 31 % of MTH, SU 104 % of BL, almost nonexistent on its first third then increasing rather abruptly; lower fin, LF 23 % of MTH; MTH 122 % of BH. Anal tube moderately sized. Lateral line system well visible, as in L. bourreti .

Oral disc ( Fig. 29C ), ODW 23 % of BL and 48 % of BW. Marginal papillae of the upper labium with larger bases than those of the lower labium but finer than those of the four other tadpoles described herein; three submarginal papillae on each side in front of the extremities of the rows P1 to P3. No denticulate papillae. KRF 1:4+4/ 3+3:1, A3 the longest, A3 and A4 subequal> A5> A2> A1; P1> P2> P3> P4; A1 about half of P4. Details of keratodonts not studied. Jaw sheaths dark brown with black serrations; lower sheath hidden, deeply fitted under the upper jaw sheath.

Coloration in life: body mottled brown with golden and dark brown pigments. Tail with dark brown blotches which are getting smaller towards the tip of the tail. Upper and lower fins and ventral side of body greyish translucent. Nares conspicuous and grey coloured. Inner gills gleam reddish through skin. Intestinal loop visible.

Colour in preservative: body and tail dorsally and laterally greyish to light brown. Distinct speckled pattern at end of body and at basis of tail. Ventral body yellowish white and fins translucent. Intestinal coils visible through skin.

The variation is based on 10 other specimens, except where noted (stages 26–41, TOL 29.4–47.8 mm (n = 9) and BL 9.1–15.1 mm). Only the ratio values different from those of the described specimen are given: BW 124– 149 % of BH; ED 9.4–12.4 % of BL; RN 44–64 % of NP; NN 59–87 % of PP; SS 50–55 % of BL; TAL 201–229 % of BL (n = 9); TMH 63–98 % of BH; TMH 54–61 % of MTH; TMW 52–67 % of BW; UF 29–32 % of MTH (n = 9); SU 97–124 % of BL; LF 24–26 % of MTH (n = 9); MTH 106–160 % of BH; ODW 24–27 % of BL; ODW 46–60 % of BW. Maximum body width can be reached in middle of abdomen. Spiracle opening direction at an angle of 30° with horizontal. More the tadpole is in an advanced stage, more the upper fin begins close to body end. The posterolateral glands not visible on all specimens. The KRF vary from 1:3+3/2+2:1 to 1:4+4/3+3:1 without clear ontogenetically driven pattern. The early stages (stage 25) have much smaller dots, sometimes even absent.

Distribution. Vietnam: Based on our data: Ha Tinh Province, Nghe An Province, Quang Binh Province ( Fig. 9 ). Laos (based on Rowley et al. 2010c): Savannakhet Province.

Natural history. One adult assigned to form 1 was collected at night of 17 June 2006 at a small stream of the secondary forest (135 m a.s.l.) next to Route 20 near the border of the NP, sitting on a larger stone along a gravel bank. A juvenile specimen with an almost resorbed tail was found at 09: 30 p. m. on 30 July 2006 (24°C, 86 % relative humidity) on a small bush inside a primary forest stream in U Bo (530 m a.s.l.). Male specimens ZFMK 71346–71347 (form 1) were collected at night in Phong Nha – Ke Bang NP. It was in early September, at the beginning of the rainy season. Specimens were on low vegetation and on a stone in the vicinity of a nearly completely dried stream bed in primary forest. In their stomachs and guts were a few worms (nematodes; presumably endoparasites), and in specimen ZFMK 71347 we found remains of a 5 mm large spider.

The tadpoles of form 1 in different developmental stages (stages 29–37) were regularly sighted syntopically with Leptobrachium chapaense and Limnonectes “ kuhlii ” inside a small stream (water temperature: 22–25°C, pH 5.0–6.0) without any vegetation in U Bo area of the Phong Nha - Ke Bang NP (480–530 m a.s.l.). All larvae were found exposed on sparse substrate like the tadpoles from Cha Noi.

The subadult male from Ha Tinh Province (form 2) was collected at the beginning of the rainy season on a steep primary lowland forest hillside ( Fig. 36C ). The specimen was found in the afternoon between leaf litter below a root. Temperature at 16:00 was 26°C at that site, relative humidity was 73 %. The specimen MNHN 2005.0235 (form 2) was found during the evening on the forest ground in leaf litter.

Tadpoles of form 2, in different stages, were collected at night (24–27°C; 92–94 % relative humidity) between the 05 th and 10 th August 2006 in terraces with backwater (water temperature 25°C, pH 7.3) of a rocky mountain stream in Cha Noi, northern Phong Nha - Ke Bang NP. The larvae were found exposed on sandy and silty but sparse substrate where they often were sighted syntopically with larvae of Leptobrachium chapaense .

Placement in molecular phylogeny. Leptolalax aereus is part of a clade that groups with high support the clades of L. minimus , L. ventripunctatus , L. nyx and L. pluvialis .

Conservation status. Known from Savannakhet Province, the south of Ha Tinh Province (within Ky Anh — Ke Go Reserve, 24,800 ha after Ziegler 2002), from Nghe An Province (Pu Huong Nature Reserve), and from the west of the neighbouring province Quang Binh (within Phong Nha - Ke Bang National Park, 85,754 ha after Ziegler et al. 2004); most probably also in forested areas in between these locations and around. Thus, given this rather large extent of occurrence we propose the status Least Concern.

Figures

FIGURE 4. Combined 16SrRNA Bayesian phylogeny and haplotype networks of 113 Leptolalax specimens with hierarchical outgroups (schematic representation in the grey box) The tree topology corresponds to the Bayesian topology obtained with three million generations, values on nodes indicate posterior probabilities (asterisks> 95 %, double asterisks> 99 %), and Maximum Likelihood bootstrap support values (> 70 %). Red numbers are the percentage of uncorrected p - sequence divergence between selected sister clades. Minimum spanning haplotype networks for two Leptolalax-clades (connected to phylogenetic tree nodes marked grey) were obtained with TCS. Numbers on haplotype connections represent number of nucleotide substitutions. Numbers of specimens included in haplotype networks are: B5-1(12); B5-2(17); B5-3(6); B5-4(1); B4-1(8); B4- 2,3,4,7,8(1); B4-5(2); B4-6(3). Sampling localities are provided as pie charts within haplotype circles, circle size corresponds to the number of sampled individuals. Abbreviations for country of origin are as follows: L—Laos, M—Malaysia, T—Thailand, V—Vietnam. Newly described species and haplotype networks are coloured.

FIGURE 9. Distribution of localities of specimens of subgenus Lalos studied in this work. Onymotopes are indicted as stars. Olive green—pelodytoides; blue—L. minimus form 2; orange yellow—L. minimus; red—L. aereus; grey—L. eos; light green – L. ventripunctatus; white—L. bourreti; black—L. pluvialis; yellow—L. nyx.

FIGURE 23. Specimens of Leptolalax in life. (A) L. aereus, MNHN 2005.0235, adult male, SVL 25.8 mm; (B) L. aereus, ZFMK 71346, adult male in its natural habitat, SVL 29.8 mm; (C) L. aereus, ZFMK 71347, adult male, SVL 29.8 mm; (D) L. aereus, ZFMK 79861, subadult male, SVL 23.4 mm; (E) L. ventripunctatus, MNHN 2005.121, adult male, SVL 24.6 mm; (F) L. ventripunctatus, adult male, not collected, in dorsal view.

FIGURE 25. Leptolalax aereus, ZMFK 71346, adult male, SVL 29.8 mm. (A) Dorsal and (B) ventral view. Right shank and foot were taken off for tissue sampling.

FIGURE 26. Leptolalax aereus, ZMFK 71346, adult male. (A) Lateral view of head, ventral view of (B) right foot and of (C) right hand. Scale bar = 5 mm (3 + 2 mm).

FIGURE 27. Leptolalax aereus, ZMFK 71346, adult male, SVL 29.8 mm. Life photograph.

FIGURE 28. Tadpole of Leptolalax aereus form 1. (A) Dorsal and (B) lateral views of a tadpole in stage 34 (ZFMK 87012), scale bar = 10 mm; (C) oral disc of a specimen in stage 31 (ZFMK 87015), scale bar = 1 mm.

FIGURE 29. Tadpole of Leptolalax aereus form 2. (A) Dorsal and (B) lateral views, and (C) oral disc of a specimen in stage 26 (ZFMK 87009), scale bars = 10 mm (a, b) and 1 mm (c).

FIGURE 36. Habitat of species of Leptolalax. (A) stream near Long Nai, habitat of L. eos and L. ventripunctatus; (B) stream at Houey Ban, habitat of L. minimus form 2; (C) stream near Ban Kengkoung, habitat of L. minimus; (D) stream at Ha Tinh, habitat of L. aereus.