SVL 21.3-24.1 mm; head longer than wide (HL 7.7-8.6 mm, HW 6.5-7.7 mm); snout round, longer than eye diameter (RL 2.6-2.8 mm, ED 2.0-2.2 mm); nostrils round, closer to the tip of snout than to eye (NS 1.1-1.6 mm, EN 1.3-1.6 mm); canthus rostralis indistinct, loreal region oblique, not concave; tympanum indistinct; vomerine teeth absent; tongue notched posteriorly. Forelimbs: Forearm slender (FLL 4.2-5.4 mm), hand length (HAL 8.7-10.4 mm); relative finger lengths I < II < IV < III, tips of fingers pointed; fingers free of webbing. Hind-limbs: Thigh slender (FeL 9.1-12.8 mm); tibia five times longer than wide (TbL 10.5-14.6 mm, TbW 1.9-3.1 mm); relative toe lengths I < II < V < III < IV; webbing formula I1-1½II1-2III2-3IV3-2V; tibio-tarsal articulation reaching to the eye when leg adpressed along body. Skin: Dorsum smooth, but with some rather large smooth flattened pustules on front part of dorsum; supratympanic fold indistinct; throat, chest, belly and underside of limbs smooth; cloacal region granular.

Colouration in life: Dorsal surface of head and body grey with brownish and reddish marking, in X-shape; a whitish stripe from eye to anterior shoulder; flank grey with black spots, dorsal surface of limbs grey with dark transverse bars; belly cream; throat and chest mottled with dark brown (Fig. 4) (determination after Bourret (1942), Taylor (1962)).

Figure 4.  

The female specimen of Microhyla butleri (IEBR A.4877; SVL 21.3 mm) in life.

This is a common species in Vietnam (Nguyen et al. 2009, Frost 2021). Elsewhere, this species has been recorded from China, Myanmar, Laos, Thailand, Cambodia, Malaysia and Singapore (Nguyen et al. 2009, Frost 2021).

Specimens were found between 19:30 and 20:30 h on the ground. The surrounding habitat was mixed secondary forest of small hardwoods and shrubs.

Size small (SVL 27.3-30.8 mm in males; SVL 33.9 mm in female); head longer than wide (HL 10.6-11.6 mm, HW 9.3-10.6 mm in males; HL 13.8 mm, HW 12.6 mm in female); snout protruding, longer than eye diameter (RL 4.1-4.5 mm, ED 3.7-4.8 mm in males; RL 5.3 mm, ED 4.9 mm in female); nostrils oval, closer to the tip of snout than to eye (NS 1.7-2.7 mm, EN 2.2-2.7 mm in males; NS 1.9 mm, EN 3.3 mm in female); canthus rostralis distinct, loreal region concave; tympanum round, distinct; vomerine teeth absent; tongue deeped notched. Forelimbs: Forearm rather thin (FLL 6.4-7.0 mm in males; FLL 8.3 mm in female), hand length (HAL 12.6-15.8 mm in males; HAL 19.8 mm in female); relative finger lengths I < II < IV < III, tips of fingers not enlarged; fingers free of webbing. Hind-limbs: Thigh short (FeL 11.8-14.9 mm in males; FeL 16.8 mm in female); tibia five times longer than wide (TbL 13.5-14.7 mm, TbW 2.5-3.0 mm in males; TbL 17.4 mm, TbW 3.1 mm in female); relative toe lengths I < II < III < V < IV; tibio-tarsal articulation reaching to the eye when leg adpressed along body. Skin: Dorsal surface of head smooth; dorsum and upper part of flanks with tubercles and glandular folds; supratympanic fold distinct; dorsolateral fold absent; dorsal surface of limbs with tubercles and glandular folds; ventral surface smooth.

Colouration in life: Dorsal surface of head and body brown grey with triangular marking between eyes, some grey spots in middle of back; dorsal surface of fore- and hind-limbs brown grey with dark bars; throat and chest transparent grey, border of throat grey with white spots; belly white (Fig. 5) (determination after Taylor (1962), Pham et al. (2016)).

Figure 5.  

The male specimen of Leptobrachella minima (IEBR A.4880; SVL 30.8 mm) in life.

In Vietnam, L. minima was known from Son La, Dien Bien, Hoa Binh, Quang Ninh and Thanh Hoa Provinces (Frost 2021). Elsewhere, this species has been recorded from Thailand and Laos (Frost 2021).

Specimens were found on the trees or on the ground along the stream between 19:30 and 21:30 h. The surrounding habitat was mixed secondary forest of hardwoods and shrubs.

Size medium (SVL 39.2-41.3 mm in males; SVL 48.3-54.6 mm in females); head longer than wide (HL 16.5-18.7 mm, HW 14.8-15.3 mm in males; HL 19.0-21.6 mm, HW 17.7-20.0 mm in females); snout round, longer than eye diameter (RL 6.1-6.6 mm, ED 4.9-5.6 mm in males; RL 7.4-8.1 mm, ED 5.9-7.2 mm in females); nostrils situated dorsolaterally on snout, closer to the tip of snout than to eye (NS 2.1-2.6 mm, EN 3.2-4.2 mm in males; NS 2.6-3.0 mm, EN 4.4-5.7 mm in females); canthus round, flat in lateral view, loreal region oblique and concave; tympanum distinct, round; vomerine teeth absent; tongue notched posteriorly. Forelimbs: Forearm slender (FLL 9.1-11.0 mm in males; FLL 12.8-14.0 mm in females), hand length (HAL 22.5-24.2 mm in males; HAL 28.2-30.1 mm in females); relative finger lengths I < II < IV < III; tips of fingers slightly swollen; fingers free of webbing. Hind-limbs: Thigh length (FeL 18.4-20.2 mm in males; FeL 24.4-25.1 mm in females); tibia six times longer than wide in males (TbL 19.0-20.8 mm, TbW 3.2-3.4 mm), tibia five times longer than wide in females (TbL 23.2-25.3 mm, TbW 3.6-5.4 mm); relative toe lengths I < II < V < III < IV; toes with rudimentary webbing; tibio-tarsal articulation reaching to the eye when leg adpressed along body. Skin: Dorsal surface head and body smooth with small pustules and minute tubercles uniformly distributed; supratympanic fold distinct; flanks smooth, large tubercles near waist absent; throat, chest, belly and ventral surface of thighs smooth.

Colouration in life: Dorsal surface of body and limbs grey; dorsum covered with irregular, diffuse dark grey and black spots; flanks light grey with a series of large well defined black spots; a pair of vertical bars on upper lip; limbs and digits with transverse dark bars. Forearm and heels yellow-orange; belly pinkish-white (Fig. 6) (determination after Lathrop et al. (1998)).

Figure 6.  

The male specimen of Leptobrachella nahangensis (IEBR A.4885; SVL 41.3 mm) in life.

In Vietnam, L. nahangensis was previously known only from Tuyen Quang Province (Nguyen et al. 2009, Frost 2021). The new record of the species from Bac Kan found approximately 19 km from the type locality in Tuyen Quang Province.

Specimens were found on the trees along the stream, between 20:00 and 22:00 h. The surrounding habitat was mixed secondary forest of small hardwoods and shrubs.

Size large (SVL 100.4-106.5 mm); head shorter than wide (HL 42.8-45.2 mm, HW 45.1-45.3 mm); snout obtusely pointed in dorsal view, longer than eye diameter (RL 15.6 mm, ED 10.9-12.5 mm); nostrils lateral, round, closer to eye than the tip of snout (NS 7.5-8.0 mm, EN 7.3-7.4 mm); canthus rostralis short, but distinct, loreal region oblique, shallowly concave; tympanum distinct, round; vomerine teeth present; tongue deeped notched. Forelimbs: Forearm short (FLL 17.4-21.4 mm), hand length (HAL 48.2-48.4 mm); relative finger lengths I < II < IV < III, tips of fingers obtuse or slightly swollen; fingers free of webbing. Hind-limbs: Thigh short (FeL 51.8-55.2 mm); tibia three times longer than wide (TbL 54.4 mm, TbW 19.4-20.2 mm); relative toe lengths I < II < V < III < IV; toes fully webbed; tibio-tarsal articulation reaching to the eye when leg adpressed along body. Skin: Skin of the upper parts covered with large elongated warts and small oval tubercles; supratympanic fold distinct; flanks with small round tubercles, more dense near dorsolateral folds; belly smooth.

Colouration in life: Dorsal surface of head body and flank dark grey; dorsum with black large elongated warts; dorsal surface of limbs with dark cross bars; ventral surface cream (Fig. 7) (determination after Liu (1950)).

Figure 7.  

The female specimen of Quasipaa boulengeri (IEBR A.4891; SVL 106.5 mm) in life.

In Vietnam, Q. boulengeri was known from Cao Bang, Son La, Tuyen Quang and Nghe An Provinces (Nguyen et al. 2009, Frost 2021). Elsewhere, this species has been recorded from China (Frost 2021).

Specimens were found in the stream, at 20:30 h. The surrounding habitat was mixed secondary forest of medium hardwoods and shrubs.

Size medium (SVL 45.2 mm in male; SVL 53.7 mm in female); head longer than wide (HL 17.1 mm, HW 14.8 mm in male; HL 21.4 mm, HW 18.6 mm in female); snout obtusely round in dorsal view, longer than eye diameter (RL 6.6 mm, ED 5.1 mm in male; RL 8.0 mm, ED 6.6 mm in female); nostrils round, closer to the tip of snout than to eye (NS 2.6 mm, EN 4.1 mm in male; NS 3.4 mm, EN 5.3 mm in female); canthus rostralis distinct, loreal region slightly concave and oblique; tympanum distinct round; vomerine teeth present; tongue deeply notched posteriorly. Forelimbs: Forearm slender (FLL 10.3 mm in male; FLL 11.8 mm in female), hand length (HAL 24.0 mm in male; HAL 30.1 mm in female); relative finger lengths I < II < IV < III, tips of fingers enlarged into discs; fingers free of webbing. Hind-limbs: Thigh slender (FeL 23.7 mm in male; FeL 29.7 mm in female); tibia five times longer than wide in the male (TbL 26.3 mm, TbW 4.6 mm), six times longer than wide in the female (TbL 32.8 mm, TbW 5.0 mm); relative toe lengths I < II < III < V < IV; webbing formula I½-½II0-1III0-1½IV1-0V; tibio-tarsal articulation reaching to the nostril when leg adpressed along body. Skin: Dorsal surface of head and body smooth; tiny spinules on flanks, upper edge of eyelid; anterior and posterior edge of tympanum; supratympanic fold indistinct, dorsolateral fold absent; throat, chest, belly and ventral surface of thigh smooth.

Colouration in life: Dorsum and upper part of flanks moss green with brown mottles, dorsal surface of limbs moss green with dark brown cross bars; upper lip with dark brown bars; throat, chest and belly cream with dark brown mottles (Fig. 8) (determination after Mo et al. (2015), Pham et al. (2016)).

Figure 8.  

The male specimen of Odorrana lipuensis (IEBR A.4893; SVL 45.2 mm) in life.

In Vietnam, O. lipuensis was known from Cao Bang and Tuyen Quang Provinces (Pham et al. 2016, Frost 2021). Elsewhere, this species has been recorded from China (Frost 2021).

Specimens were found on trees, between 20:00 and 20:30 h, near the waterfall in a rocky stream. The surrounding habitat was mixed secondary forest of small hardwoods, shrubs and vines.

Size medium (SVL 39.7 mm in male; SVL 56.4-60.3 mm in females); head longer than wide (HL 14.5 mm, HW 11.2 mm in the male; HL 22.1-24.0 mm, HW 17.9-19.1 mm in females); snout obtusely pointed, longer than eye diameter (RL 5.9 mm, ED 4.6 mm in male; RL 8.6-9.0 mm, ED 6.2-6.6 mm in females); nostrils round, closer to the tip of snout than to eye (NS 2.4 mm, EN 3.9 mm in male; NS 3.4-4.2 mm, EN 5.1-5.3 mm in females); canthus rostralis distinct, loreal region concave; tympanum eliptic, distinct; vomerine teeth present; tongue notched posteriorly. Forelimbs: Forearm slender (FLL 8.9 mm in male; FLL 11.0-12.6 mm in females), hand length (HAL 18.7 mm in male; HAL 26.5-27.0 mm in females); relative finger lengths I < II < IV < III, tips of fingers not enlarged; fingers free of webbing. Hind-limbs: Thigh slender, long (FeL 21.6 mm in male; FeL 33.2-33.9 mm in females); tibia seven times longer than wide in male (TbL 25.3 mm, TbW 3.3 mm); tibia six times longer than wide in females (TbL 36.5-38.8 mm, TbW 6.1-7.2 mm); relative toe lengths I < II < III < V < IV; webbing formula I0-½II0-1III½-1IV1-0V; tibio-tarsal articulation reaching to the nostril when leg adpressed along body. Skin: Dorsal surface of head and body smooth with some small tubercles; supratympanic fold distinct, some short, oblique dermal folds on limbs; a Λ-shaped fold between shoulders; dorsolateral fold present; ventral surface smooth.

Colouration in life: Dorsal surface light brown; flanks whitish-brown; dorsal surface of limbs with dark brown transverse bars; a small black stripe from nostril to eye; sides of limbs with dark pattern; ventral surface yellowish-white; gular region marbled with grey; ventral surface of hind-limbs yellow (Fig. 9) (determination after Bourret (1942), Inger et al. (1999)).

Figure 9.  

The male specimen of Rana johnsi (IEBR A.4895; SVL 39.7 mm) in life.

In Vietnam, R. johnsi was known from Lao Cai and Ha Giang Provinces in the North to Lam Dong and Dong Nai Provinces (Nguyen et al. 2009, Frost 2021). Elsewhere, this species has been recorded from China, Taiwan, Thailand and Cambodia (Nguyen et al. 2009, Frost 2021).

Specimens were found on the ground, between 19:00 and 20:30 h. The surrounding habitat was mixed secondary forest of small hardwoods and vines.

This species is morphologically similar to Nidirana lini. However, it differs from N. lini by having a smaller body size in the male (SVL 39.7 mm vs. 44.2-61.2 mm in N. lini) and the absence of vocal sacs in males (vs. present in N. lini) (Chou 1999).

Size small (SVL 32.9 mm); head longer than wide (HL 12.0 mm, HW 11.8 mm); snout round, smaller than eye diameter (RL 4.6 mm, ED 4.9 mm); nostrils oval, closer to the tip of snout than to eye (NS 2.0 mm, EN 2.5 mm); canthal edges rounded, loreal region oblique, slightly concave; tympanum distinct, round; vomerine teeth absent; tongue notched posteriorly. Forelimbs: Forearm short and gracile (FLL 7.2 mm), hand length (HAL 16.3 mm); relative finger lengths I < II < IV < III, tips of fingers enlarged into discs; fingers free of webbing. Hinlimbs: Thigh moderately long (FeL 18.2 mm); tibia six times longer than wide (TbL 19.0 mm, TbW 2.9 mm); relative toe lengths I < II < III < V < IV; webbing formula I1-2II1-2III1-2IV2-1V; tibio-tarsal articulation reaching to the nostril when leg adpressed along body. Skin: Dorsum and dorsal parts of head; limbs overall smooth, but with some small tubercles; supratympanic fold indistinct; ventral part of forearm smooth; dorsolateral folds absent; throat, chest, belly and ventral part of thighs granular.

Colouration in life: Dorsal surface of head and body, flank green olive, a dark green irregular patch running from between eyes to shoulder; upper and lower lip green olive with some creamy white spots; dorsal part of limbs green olive with transverse dark green bands; throat and margin of throat, chest and belly marbled with white; ventral part of limbs greyish-white (Fig. 10) (determination after Nguyen et al. (2013), Mo et al. (2013)).

Figure 10.  

The male specimen of Gracixalus nonggangensis (IEBR A.4899; SVL 32.9 mm) in life.

In Vietnam, G. nonggangensis was previously known from Cao Bang Province (Nguyen et al. 2013). Elsewhere, this species has been recorded from China (Frost 2021).

Specimen was found at 20:00 h on a tree, about 0.5 m above the ground. The surrounding habitat was mixed secondary forest of hardwoods and shrubs.

The specimens of G. nonggangensis from Bac Kan only differ slightly from those in the description of Mo et al. (2013) in having a rostral length shorter than eye diameter (vs. rostral length longer than eye diameter).

Size medium (SVL 40.6-42.8 mm in males; SVL 48.7-57.6 mm in females); head longer than wide (HL 14.9-16.4 mm, HW 14.5-15.7 mm in males; HL 19.0-22.8 mm, HW 18.3-20.9 mm in females); snout slightly pointed, longer than eye diameter (RL 6.4-7.1 mm, ED 4.6-5.6 mm in males; RL 7.5-9.5 mm, ED 6.1-7.5 mm in females); nostrils oval, closer to the tip of snout than to eye (NS 32.4-3.0 mm, EN 4.1-4.7 mm in males; NS 3.6-3.8 mm, EN 2.3-6.1 mm in females); canthus rostralis well-developed, slightly constricted, loreal region concave; tympanum distinct, round; vomerine teeth absent; tongue deeply notched posteriorly. Forelimbs: Forearm slender (FLL 8.1-9.0 mm in males; FLL 12.0-12.4 mm in females), hand length (HAL 21.1-21.7 mm in males; HAL 26.8-32.2 mm in females); relative finger lengths I < II < IV < III, tips of fingers enlarged into discs; webbing formula I1-1½II1-2III1-1IV. Hind-limbs: Thigh slender (FeL 20.8-21.7 mm in males; FeL 26.5-30.3 mm in females); tibia six times longer than wide (TbL 22.3-25.1 mm, TbW 3.4-3.7 mm in males; TbL 27.8-31.4 mm, TbW 4.4-5.2 mm in females); relative toe lengths I < II < III < V < IV; webbing formula I½-1II⅓-1III½-1IV1-⅓V; tibio-tarsal articulation reaching to the position between the eye and nostril when leg adpressed along body. Skin: Dorsal surface of head, body and upper part of flanks smooth; supratympanic fold distinct; limbs without distinct dermal flaps and folds, except for a weakly developed fold along outer edge of 4^th finger and 5^th toe; weak tubercles and protuberances on outer edge of tarsus; throat, chest smooth; belly, ventral surface of limbs granular.

Colouration in life: Dorsal surface of head and body reddish-brown with some darker markings; flanks light brown with dark brown reticulation and yellow spots; ventral light grey with some indistinct small dark spots; limbs dorsally light reddish-brown with dark crossbars (Fig. 11) (determination after Ziegler and Köhler (2001), Ostroshabov et al. (2013)).

Figure 11.  

The male specimen of Rhacophorus orlovi (IEBR A.4900; SVL 40.6 mm) in life.

In Vietnam, R. orlovi was known from Dien Bien and Son La Provinces in the North to Gia Lai Province in the Central Highlands (Nguyen et al. 2009). Elsewhere, this species has been recorded from Laos (Frost 2021).

Specimens were found on trees along the trail, between 20:00 and 21:00 h, 2-3 m from the ground. The surrounding habitat consisted of mixed secondary forest composed of small hardwoods and vines.