Leptolalax (Lalos) ventripunctatus Fei, Ye & Li, 1991

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 : 50-55

Leptolalax (Lalos) ventripunctatus Fei, Ye & Li, 1991

( Fig. 21–24 )

Leptolalax ventripunctatus Fei, Ye & Li in: Fei et al. 1991: 95, 97, 213, 274.

Onymophoront, by original designation: holophoront (holotype), CIB 890063 , adult male, SVL 27.0 mm (Fei et al. 1992: 51). Collected by Luo Jiarui, 17 May 1989 .

Onymotope: Mengla (21°29’ N, 101°15’ E; alt. 850 m), Yunnan Province, China .

Material examined. Laos. Phongsaly Province, Phongsaly water supply river (21°40’ N, 102°06’ E; 1000 m): MNHN 2005.0111 – 0116 , adult males; MNHN 2006.2576 , 1 tadpole (DNA voucher), coll. Annemarie Ohler, 31 January 2005 ; — Nathen (21°24’N, 101°58’ E; 600 m): MNHN 2005.0137 – 0140 , adult males, MNHN 2006.2577 , 1 tadpole (DNA voucher), coll. Annemarie Ohler, 9 February 2005 ; — Long Nai (21°14' N, 101°56' E; 800 m), MNHN 2004.0270 – 0273 , MNHN 2005.0117 – 0136 , adult males, coll. Annemarie Ohler, 14 and 15 July 2004 and 4 February 2005 ; — Nam Ou (22°03’ N, 102°16’ E; 520 m), MNHN 2005.0142 – 0144 , adult males, MNHN 2006.2578 – 2588 , 11 tadpoles, coll. Annemarie Ohler, 13 February 2005 ; — Houey Phihet (21°60’ N, 102° 17’ E; 500 m): MNHN 2005.0145 , adult male, coll. Annemarie Ohler, 16 February 2005 ; Vietnam. Vinh Yen District, Tam Dao (21°27’ N, 105°38’ E): MVZ 223641–42 , coll. Theodore J. Papenfuss, 22 April 1996 .

Comment. This species was described from extreme southern Yunnan, near the Lao border. We had the opportunity to do fieldwork on the Lao side and discovered this small-sized Leptolalax which is sympatric with the new species L. eos described above. Specimens allocated to the present species resemble the onymophoront in morphology and are therefore assigned to ventripunctatus (no molecular data exist so far from the Yunnan locality). The collection locality in Laos is less than a hundred kilometres from the onymotope. Most of the Lao specimens were included in the molecular analysis and show great overall genetic similarity. They form a clade with specimens from Tam Dao (MVZ 223641 – 42) which are genetically very similar. In consequence, these specimens are included in L. ventripunctatus .

Diagnosis. (Based on specimens from Laos, not on onomophoront). 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: rather small-sized species (males 23.7–27.7 mm; females 31.5–35.0 mm) ( Table 3) with rudimentary webbing and no fringes on toes; tympanum distinct; dermal ridges under toes distinct; finger tips slightly enlarged; dorsal skin with indistinct glandular warts (Table 4); dorsum grey brown with spots, rather large spots on flanks; ventral side with distinct dark spots on chest and belly; iris copper above, grey brown below ( Table 5).

Description of the adult male MNHN 2004.0270. Size and general aspect: (1) Specimen of rather small size (SVL 25.2 mm), body moderately slender.

Head. (2) Head of medium size, narrower (HW 8.8 mm) than long (HL 10.0 mm; MN 8.4 mm; MFE 6.7 mm; MBE 3.3 mm), rather flat. (3) Snout slightly protruding, its length (SL 4.4 mm) longer than horizontal diameter of eye (EL 3.6 mm). (4) Canthus rostralis distinct, rounded, loreal region concave, vertical. (5) Interorbital space flat, slightly narrower (IUE 2.9 mm) than upper eyelid (UEW 3.1 mm) but larger than internarial distance (IN 2.7 mm); distance between front of eyes (IFE 5.2 mm) about two-thirds of the distance between back of eyes (IBE 7.8 mm). (6) Nostrils rounded, closer to eye (EN 1.9 mm) than to tip of snout (NS 2.1 mm). (8) Tympanum (TYD 1.9 mm) distinct, rounded; about half eye diameter, tympanum-eye distance (TYE 0.9 mm) half the diameter of tympanum. (11) Tongue moderate, cordate.

Forelimbs. (12) Forearm rather short, thin (FLL 7.3 mm), longer than hand (HAL 7.0 mm), not enlarged. (13) Fingers I, II and IV rather short and rather strong; finger III long and rather strong (TFL 3.9 mm). (15) Tip of fingers rounded, slightly enlarged. (16) Fingers without dermal fringe.

Hindlimbs. (19) Shanks about four times longer (TL 12.0 mm) than wide (TW 3.2 mm), shorter than thigh (FL 12.2 mm) and than distance from base of internal metatarsal tubercle to tip of toe IV (FOL 12.1 mm); heel reaching mid-eye when limbs folded forward. (20) Toe IV (FTL 6.4 mm) about one-third of the distance from base of tarsus to tip of toe IV (TFOL 19.4 mm). (22) Tip of toes rounded, slightly enlarged. (23) Webbing rudimentary, toes without fringes (MTTF 4.9 mm; MTFF 4.9 mm; TFTF 7.3 mm; FFTF 7.7 mm). (24) Dermal fringe along toe V absent. (26) Inner metatarsal tubercle short and very prominent (conical); its length (IMT 1.3 mm) 2.1 times in length of toe I (ITL 2.7 mm). (27) Tarsal fold absent.

Skin. (29) Dorsal and lateral parts of head and body: snout, region between eyes and side of head smooth; back with indistinct glandular warts; flanks with glandular warts. (30) Supratympanic fold distinct, from eye to above shoulder. (31) Dorsal parts of limbs: forelimbs with few indistinct glandular warts; thigh, shank and tarsus smooth. (32) Ventral parts of head, body and limbs: throat, chest and belly smooth; thigh with glandular warts. (33) Presence of macroglands: lateroventral glands present as series of glands forming continous glandular ridge; rather large, distinct rounded or oval femoral and axillary glands, and oval suprabrachial glands.

Coloration. In alcohol: (34) Dorsal and lateral parts of head and body: dorsal parts of head and dorsum greyishbrown with whitish zones and two black spots between eyes; flanks grey brown with rather large blackish spots; loreal region light brown with distinct dark brown spot; tympanic region including tympanum light brown with blackish line at supratympanic fold; upper lip light brown with brown bands. (35) Dorsal parts of limbs: dorsal part of forelimbs beige with brown crossbands on lower part; dorsal part of thigh, of shank and of foot beige with brown crossbands; posterior part of thigh brown with a few small white spots. (36) Ventral parts of head, body and limbs: throat whitish with traces of brown; margin of throat light brown with whitish spots; chest whitish with few brown spots; belly whitish with dense brown spots; thigh light brown with whitish spots; webbing brown; macroglands white.

In life ( Fig. 23E–F ): Iris copper in upper third, grey brown in lower part. Dorsal parts of head, of back and of upper part of flanks grey brown with darker spots and black spots between eyes; lower part of flanks greyish with black spots; loreal and tympanic region brown with black canthal and supratympanic band; tympanum brown; upper lip brown with blackish bands; upper part of forelimb orange; lower part greyish brown with blackish bands; thigh, shank and foot greyish brown with black crossbands; posterior part of thigh greyish brown with dark brown bands; throat light grey, transparent; border of throat grey with white spots; chest and belly creamy white with brown spots; ventral part of thigh dark grey brown with white dots; webbing grey brown. Macroglands white.

Male secondary sexual characters: (38) Vocal sacs present; indistinct on throat; pair, slit-like openings posterior on mouth floor.

Variation. Specimens are rather homogenous in colour pattern and show only minor variation in extent of dark pattern on ventral side and presence of spots on dorsum and lateral side. The specimens also show some variation in presence of warts and skin ridges. Female sexual characters: oviduct convoluted, translucent; ovary with small creamy whitish oocytes.

The lateroventral glandular ridges are continous in all specimens. There is some variation in size and shape of femoral and axillary glands that are smaller in some specimens and more or less oval or round in shape.

Tadpole. The external morphology is based on a DNA voucher specimen in stage 33 (MNHN 2006.2576; BL 16.1 mm). The description of the tail which is missing in the DNA voucher is based on a specimen in stage 36 (MNHN 2006.2578).

In dorsal view ( Fig. 24A ), body elliptical elongate. In lateral view ( Fig. 24B ), BW 134 % of BH. Eyes moderately sized, ED 9.6 % of BL, bulging. Nares moderately sized, RN 40 % of NP; NN 77 % of PP. Spiracle is a short tube, small, SS 50 % of BL; opening crescent-shaped, situated on an axis just below apex of myotomes of caudal muscle. Tail long; tail musculature, TMH 82 % of BH, TMW 62 % BW, slightly bulging on less than the proximal third, almost reaching tail tip. Upper fin, SU 108 % of BL, almost nonexistent in its proximal third then increasing rather abruptly; lower fin convex, following largely the caudal muscle; point of maximum height of tail located before its proximal third. Anal tube moderately sized. Lateral line system as in L. bourreti but with an additional line running vertically on the lateral sac from the ventral line until the beginning of the ventral part. Glands present but faintly visible.

Oral disc ( Fig. 24C ) moderately sized, ODW 28 % of BL and 52 % of BW. Marginal papillae of lower labium smaller than those of upper labium and more or less round to short, cylindrical, decreasing in size towards centre then increasing again at the extremity of indentation with four larger papillae; five submarginal papillae on left side and two on right side on lower labium at commissure and in front of keratodont rows P1 and P2. No denticulate papillae. KRF 1:4+4/3+3:1, A4> A5> A3> A2> A1; P2 = P1> P3> P4; A1 about half of P4. Details of keratodonts not studied. Jaw sheaths black; upper sheath a large arch with a median convexity formed by the three median serrations, the median one bigger and stronger than the others; lower sheath hidden, arranged deeply under the upper jaw sheath.

Coloration in life: Tadpole MNHN 2006.2578 reddish dorsally with indistinct spots; lateral body light grey with distinct grey spots; belly greyish white. Tadpole MNHN 2006.2577 uniformly greyish brown, its tail beige with dark spots; belly bluish white; oral region whitish grey; iris golden.

Coloration in preservative: upper part of body sandy orange, the colour fading from before eyes to snout. Flanks (lymphatic sacs) grey ochre. Ventral side of body dirty white. Caudal muscle from sandy for the upper part to ivory for the lower part in gradation; small light brown spots more numerous on the upper part than on the lower part, giving a mottled aspect. Fins translucent with the same small spots as those on the caudal muscle but forming small blotches isolated from each other on the upper fin; lower fin spotless. Rims of nares white.

Tadpole variation is described on the basis of 12 other specimens, except when noted (MNHN 2006.2577, 2006.2579–2588, in stages 25–36, TOL 31.0– 55.9 mm and BL 9.0– 16.1 mm). Only the ratio values different from those of the described specimen are given: BW 129–144 % of BH; ED 8.4–10.7 % of BL; RN 35–58 % NP; NN 70–82 % of PP; SS 42–53 % of BL; TAL 212–251 % of BL (n = 11); TMH 63–85 % of BH; TMH 53–70 % of MTH (n = 11); TMW 48–61 % of BW; UF 28–36 % of MTH (n = 11); SU 92–116 % of BL; LF 22–29 % of MTH (n = 11); MTH 115–126 % of BH (n = 11); ODW 25–32 % of BL (n = 11); ODW 43–49 % of BW (n = 11). The more the tadpoles are in advanced stages, the more their upper fin begins close to body end. The upper fin increases at the first quarter and the lower fin can be straight and so increasing in height anteroposteriorly in a few specimens. The KRF varies from 1:2+2/2+2:1 (stage 25) to 1:4+4/3+3:1 (stages 29–36) through the intermediate KRF 1:3+3/2+2:1 (stages 25–34) and 1:3+3/3+3:1 (stages 27–28). The coloration of the tail is more extended on most of the other specimens: proximal half of caudal muscle tan, this coloration grouping in blotches on the distal half with the ground colour beige, similar blotches on the distal third of the lower fin, upper fin smoked with tan pigments.

The lateral spots in the tadpole series described herein are less pronounced than in those figured by Fei et al. (2009). We assume that this might be due to the strong contrast between black and white in the drawing of Fei et al. (2009).

Distribution. China: Yunnan Province (Mengla County); Laos: Phongsaly Province (Phongsaly District); Vietnam: Vinh Phuc Province (Vinh Yen District) ( Fig. 9 ).

Natural history. Specimens were found (July 2004 and January–February 2005) in forests at a distance up to 1 m from small rivulets ( Fig. 36A ). Most specimens were very close to the water at a distance of 0.2 to 0.5 m. They were sitting either on the ground (stones, sand, earth) or above the ground on leaves or rocks, usually covered by low vegetation. Only a few specimens were sitting in the water. Most of the specimens were in breeding condition. The tadpoles were collected in a puddle of 40 × 30 cm along a stream (but connected to the stream) with a weak current. They were usually motionless on the bottom, hidden within the gravel. Another specimen was collected in a stream of a width of 10 m and a maximum depth of 50 cm, at a depth of 10 cm. The bottom was covered of stones and dead leaves under which the tadpoles were hidden. In these streams, adults of Limnonectes kuhlii and Polypedates “ leucomystax ” were also observed.

Placement in molecular phylogeny. Leptolalax ventripunctatus is part of a highly supported clade that groups L. minimus , L. aereus , L. pluvialis and L. nyx . The specimens allocated to L. ventripunctatus form a well supported clade which, with no support, is sister to the clade that goups L. minimus and L. aereus .

Conservation status. This work adds more data on distribution and extent of occurence of this species. It is relatively abundant in convenient habitat, within its relatively small range. It might encounter threats by habitat loss through shift and burning agriculture. We propose therefore to change the status of L. ventripunctatus from Data Deficient to Near Threatened.

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 21. Leptolalax ventripunctatus, MNHN 2004.0270, adult male, SVL 25.2 mm. (A) Dorsal and (B) ventral view.

FIGURE 22. Leptolalax ventripunctatus, MNHN 2004.0270, 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 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 24. Tadpole of Leptolalax ventripunctatus. (A) Dorsal and (B) lateral views of a specimen in stage 33 (MNHN 2006.2576), scale bar = 10 mm; (C) oral disc of a specimen in stage 29 artificially expanded (MNHN 2006.2577), scale bar = 1 mm. Tip of tail cut for tissue sampling.

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.