Quasipaa ohlerae, Pham & Hoang & Phan & Pham & Ong & Nguyen & Ziegler & Nguyen, 2025

Pham, Cuong The, Hoang, Chung Van, Phan, Tien Quang, Pham, Anh Van, Ong, An Vinh, Nguyen, Vien Hong Thi, Ziegler, Thomas & Nguyen, Truong Quang, 2025, Taxonomic revision of the Quasipaa verrucospinosa complex (Amphibia, Dicroglossidae) in Vietnam, with descriptions of two new species, ZooKeys 1240, pp. 139-175 : 139-175

Quasipaa ohlerae sp. nov.

Figs 7 , 8 , 9 , 10 , 11 , Table 6

Paa verrucospinosa : Hu et al. 2005: 340–341.

Quasipaa verrucospinosa : Yan et al. 2021: 1–7. Suwannapoom et al. 2021: 1–12, fig. 3.

Quasipaa cf. verrucospinosa : Dau et al. 2024: 9–11, fig. 5.

Type material.

Holotype. • IEBR A.5159 , adult male, collected by T. Q. Phan and H. Q. Nguyen, on 17 November 2021, in Xuan Lien Nature Reserve (19°59.076'N, 104°59.095'E, at an elevation of 806 m a. s. l.), Thuong Xuan District, Thanh Hoa Province, Vietnam . Paratypes. (n = 12) • IEBR A.5160 , adult female, collected by T. Q. Phan and C. V. Hoang, on 20 October 2021, in Xuan Lien Nature Reserve (19°52.041'N, 105°12.569'E, at an elevation of 297 m a. s. l.), Thuong Xuan District, Thanh Hoa Province, Vietnam ; IEBR A.5161 –5163, three adult males and IEBR A.5164 –5166, three adult females, collected by C. T. Pham and C. V. Hoang, on 25 August 2012, in Xuan Lien Nature Reserve (19°51.446'N, 105°12.153'E, at an elevation of 423 m a. s. l.), Thuong Xuan District, Thanh Hoa Province, Vietnam ; ZVNU 11 , adult male, collected by A. V. Pham, on 22 December 2012, in Copia Nature Reserve (21°20.216'N, 103°34.822'E, at an elevation of 950 m a. s. l.), Thuan Chau District, Son La Province, Vietnam ; ZVNU 12 , adult male, collected by T. Q. Nguyen, A. V. Pham, and H. N. Ngo, on 17 September 2014, in Copia Nature Reserve (21°20.216'N, 103°34.822'E, at an elevation of 950 m a. s. l.), Thuan Chau District, Son La Province, Vietnam ; ZVNU 14 , adult male and ZVNU 13 , adult female, collected by A. V. Pham and N. B. Sung, on 16 September 2016, in Copia Nature Reserve (21°20.216'N, 103°34.822'E, at an elevation of 950 m a. s. l.), Thuan Chau District, Son La Province, Vietnam ; IEBR A. 5167 , adult female, collected by A. V. Ong, on 26 October 2021, in Pu Hoat Nature Reserve (19°44.245'N, 104°57.474'E, at an elevation of 655 m a. s. l.), Que Phong District, Nghe An Province, Vietnam .

Diagnosis.

Both morphological characteristics (body very stout, skin rough with dermal ridges and tubercles, forelimbs of males strongly enlarged, with inner side of arms, fingers or chest and belly with black spines) ( Fei et al. 2009) and molecular data revealed the new species to be nested within Quasipaa . Quasipaa ohlerae sp. nov. is distinguishable from its congeners by a combination of the following morphological characteristics: (1) SVL 86.7–107.8 mm in males and 92.7–107.0 mm in females; (2) head broader than long (HL / HW 0.89 in males, 0.88 in females); (3) vomerine teeth present; (4) external vocal sacs absent; (5) tympanum visible, round; (6) dorsum with thick ridges and small round tubercles; (7) flanks covered by oval and round tubercles; (8) supratympanic fold present; (9) dorsolateral fold absent; (10) ventral surface of arms and all fingers with spines in males; (11) fingers I and II with nuptial pad in males; (12) each chest tubercle with one black spine in males; (13) females with yellowish cream eggs; (14) toes fully webbed to distal end of terminal phalanx; and (15) in life, dorsum dark brown, chest and belly immaculate white, iris dark green.

Description of holotype.

A large frog (SVL 103.1 mm); habitus robust with enlarged head (HL / SVL 0.38, HW / SVL 0.43); head broader than long (HL 39.4 mm, HW 44.6 mm); snout round anteriorly in dorsal view, projecting beyond lower jaw; nostril lateral, closer to eye than to the tip of snout (NS 9.0 mm, EN 7.9 mm); canthus rostralis indistinct; loreal region oblique and slightly concave; rostral length greater than eye diameter (RL 16.0 mm, ED 13.0 mm); internarial distance wider than interorbital distance and upper eyelid width (IND 10.2 mm, IOD 7.4 mm, UEW 9.3 mm); tympanum visible (TD 4.0 mm) smaller than the distance from tympanum to eye (TYE 7.0 mm), ~ 30 % eye diameter; vomerine teeth in two oblique ridges; tongue cordiform, notched posteriorly; external vocal sac absent.

Forelimbs: arms short; upper arm length (UAL) 23.1 mm, forearm length (FAL) 51.0 mm; relative finger lengths: II <I <IV <III; fingers free of webbing; narrow dermal ridge on sides of fingers present on fingers II, III; tips of fingers swollen, not expanded; subarticular tubercles prominent, round, formula 1, 1, 2, 2; inner metatarsal tubercle oval; outer metatarsal tubercle elongate; fingers I and II with nuptial pad.

Hindlimbs: tibia length longer than thigh length (FeL 52.8 mm, TbL 60.3 mm), ~ 3.2 × longer than wide (TbW 19.1 mm); tips of toes swollen, slightly round; relative length of toes: I <II <V <III <IV; toes fully webbed to distal end of terminal phalanx; dermal ridge present on outer sides of toes I and V; subarticular tubercles prominent, elongate, formula 1, 1, 2, 3, 2; inner metatarsal tubercle elongate; outer metatarsal tubercle absent; tibio-tarsal articulation reaching to nostril.

Skin texture in life: dorsal surface of head with oval and round tubercles, dorsum with thick ridges intermixed with small round tubercles; flanks covered by oval and round tubercles; supratympanic fold distinct, extending from eye to angle of jaw; dorsolateral fold absent; dorsal surface of forelimbs and hindlimbs with small tubercles; belly and ventral surface of thighs smooth.

Nuptial spines: body of males with spines except for ~ 1 / 3 posterior part of belly and ventral surface of hindlimbs; dense spines on lower flanks, ventral surface of forelimbs, lower lip, throat, chest, 2 / 3 anterior part of belly and fingers I, II, III; dorsum, upper flanks, upper lip, dorsal surface of fore- and hindlimbs, and finger IV with small spines, scattered; each chest tubercle with one black spine.

Coloration in life: iris dark green; dorsum and upper part of flanks dark brown; lower part of flanks whitish brown with white tubercles and black spines on top; dorsal surface of limbs yellowish brown with dark crossbars; throat white with brown markings; ventral surface of limbs, chest, and belly immaculate white; toe webbing dark brown.

Coloration in preservative: coloration in preservative is the same in life but somewhat faded.

Sexual dimorphism.

Measurements and morphological characteristics of the type series are provided in Table 6 . The male specimens have a nuptial pad on fingers I and II and black spines on lower flanks, ventral surface of forelimbs, lower lip, throat, chest, 2 / 3 anterior part of belly, and all fingers. The females contained yellowish cream eggs, wholly unpigmented.

Ecological notes.

Specimens were found between 19: 00 and 23: 00 in the headwaters of rocky streams (Fig. 12 A ). They were found in the water or on the ground of stream banks at elevations between 300 and 950 m a. s. l. The surrounding habitat was secondary forest of large, medium-sized, and small hardwoods mixed with shrubs and vines (Fig. 12 B ). Air temperatures at the sites ranged from 20.3–27.8 ° C and relative humidity was 65–83 %. Male advertisement calls and tadpoles of the species had not been recorded during our field surveys. Other amphibian species found at the sites included Leptobrachella eos (Ohler, Wollenberg, Grosjean, Hendrix, Vences, Ziegler & Dubois, 2011) , Xenophrys lancangica Lyu, Wang & Wang, 2023 , Limnonectes bannaensis Ye, Fei, Xie & Jiang, 2007 , Amolops tanfuilianae Sheridan, Phimmachak, Sivongxay & Stuart, 2023 , Odorrana chloronota (Günther, 1876) , O. nasica (Boulenger, 1903) , O. tiannanensis (Yang & Li, 1980) , Hylarana maosonensis Bourret, 1937 , Kurixalus sp. , Polypedates megacephalus Hallowell, 1861 , and Rhacophorus orlovi Ziegler & Köhler, 2001 . During to field surveys in Vu Quang National Park (Ha Tinh Province) and Pu Hoat Nature Reserve (Nghe An Province) in April 2025, We also observed some individuals of the new species.

Distribution.

Quasipaa ohlerae sp. nov. is currently known from Son La (Copia Nature Reserve), Thanh Hoa (Xuan Lien Nature Reserve), and Nghe An (Pu Hoat Nature Reserve) provinces, Vietnam. Data obtained from GenBank shows that this species was also recorded from Yunnan Province in China; Phongsaly Province in Laos; and Nan Province in Thailand ( Suwannapoom et al. 2021; see Discussion below).

Comparisons.

We compared the new species with its congeners. Quasipaa ohlerae sp. nov. differs from Q. verrucospinosa by having nuptial spines on all fingers of males (vs absent on finger IV); males with nuptial spines on ventral surface of arms (vs absent); dense spines on lower lip and throat of males (vs small and scattered); a smaller ratio of TD / ED (0.32, n = 7 in males and 0.34, n = 6 in females vs 0.53, n = 7 in males and 0.50, n = 7 in females); a greater ratio of TYE / TD (1.68, n = 7 in males and 1.61, n = 6 in females vs 1.16, n = 7 in males and 1.14, n = 7 in females), inner metatarsal tubercle oval (vs inner metatarsal tubercle round); different dorsal color pattern (dark brown vs yellowish grey); different ventral color pattern (immaculate white vs pale yellow); iris dark green (vs pale copper); and females with wholly unpigmented eggs (vs melanic poles).

Quasipaa ohlerae sp. nov. differs from Q. acanthophora by having the dorsum with thick ridges (vs small tubercles); males with nuptial spines on ventral surface of arms (vs absent); males with nuptial spines on all fingers (vs absent on finger IV); dense spines present on throat and chest of males (vs small and scattered); and iris dark green (vs copper on upper and greyish on lower).

Quasipaa ohlerae sp. nov. differs from Q. boulengeri by having the dorsum with thick ridges and round tubercles (vs elongate ridges), males with nuptial spines on all fingers (vs absent on finger IV), males with nuptial spines on throat and ventral surface of arms (vs absent), different ventral color pattern (immaculate white vs pale yellow), and iris dark green (vs copper on upper and greyish on lower).

Quasipaa ohlerae sp. nov. differs from Q. courtoisi by having a smaller size in males (SVL 86.7–107.8 mm, n = 7 vs 126 mm, n = 1), males with nuptial spines on throat and ventral surface of arms (vs absent) and males with nuptial spines on all fingers (vs absent on finger IV).

Quasipaa ohlerae sp. nov. differs from Q. delacouri by having the dorsum with thick ridges and round tubercles (vs smooth); males with nuptial pad on fingers I and II (vs absent); and males with nuptial spines (vs absent); different dorsal color pattern (dark brown vs brick red with black spots); and tibio-tarsal articulation reaching to nostril (vs tibio-tarsal articulation reaching to tip of snout), a greater ratio of TD / ED (0.32, n = 7 in males and 0.34, n = 6 in females vs 0.26, n = 3 in males and 0.24, n = 3 in females); a smaller ratio of TYE / TD (1.68, n = 7 in males and 1.61, n = 6 in females vs 2.15, n = 3 in males and 1.93, n = 3 in females) (Figs 13 – 15 , Table 5 ).

Quasipaa ohlerae sp. nov. differs from Q. exilispinosa by having a larger size (SVL 86.7–107.8 mm, n = 7 in males and 92.7–107.0 mm, n = 6 in females vs SVL 44.2–66.5 mm, n = 20 in males and 40.0– 63.3 mm, n = 20 in females); dorsum with thick ridges (vs small tubercles); males with nuptial spines on throat and ventral surface of arms (vs absent); males with nuptial spines on all fingers (vs absent on finger IV); and iris dark green (vs copper on upper and greyish on lower).

Quasipaa ohlerae sp. nov. differs from Q. fasciculispina by having a smaller ratio of TYE / TD in males (1.68, n = 7 vs 2.0, n = 1); each chest tubercle with only one black spine in males (vs each chest tubercle with 5–10 black spines); iris dark green (vs bright copper-colored); and external vocal sac absent (vs vocal sac openings in floor of mouth).

Quasipaa ohlerae sp. nov. differs from Q. jiulongensis by having the dorsum with thick ridges (vs small tubercles); males with nuptial spines on throat and ventral surface of arms of males (vs absent); males with nuptial spines on all fingers (vs absent on fingers III and IV); the absence of pale-colored longitudinal stripes on upper jaw edge (vs present); and the absence of four or five yellow dorsal dots arranged in longitudinal rows (vs present).

Quasipaa ohlerae sp. nov. differs from Q. robertingeri by having the dorsum with thick ridges and round tubercles (vs elongate ridges); males with nuptial spines on all fingers (vs absent on finger IV); males with nuptial spines on throat and ventral surface of arms (vs absent); different ventral color pattern (immaculate white vs pale yellow); and iris dark green (vs copper on upper and greyish on lower).

Quasipaa ohlerae sp. nov. differs from Q. shini by the males having nuptial spines on all fingers (vs absent on finger IV), on throat and ventral surface of arms (vs absent), and each chest tubercle with only one black spine in males (vs each chest tubercle with 3–8 black spines).

Quasipaa ohlerae sp. nov. differs from Q. spinosa by having the dorsum with thick ridges (vs small tubercles); the absence of pale-colored longitudinal stripes on upper jaw edge (vs present); males with nuptial spines on throat and ventral surface of arms of males (vs absent); and males with nuptial spines on all fingers (vs absent on fingers III and IV).

Quasipaa ohlerae sp. nov. differs from Q. taoi by its lager size (SVL 86.7–107.8 mm, n = 7 in males and 92.7–107.0 mm, n = 6 in females vs 79.6–84.3 mm, n = 3 in males and 64.6–69.9 mm, n = 3 in females); a greater ratio of TYE / TD (1.68, n = 7 in males and 1.61, n = 6 in females vs 1.11, n = 3 in males and 1.20, n = 3 in females); the presence of nuptial spines on chest and belly in males (vs absent); iris dark green (vs dark copper); and tibio-tarsal articulation reaching to nostril (vs tibio-tarsal articulation reaching to tip of snout).

Quasipaa ohlerae sp. nov. differs from Q. yei by its larger size (SVL 86.7–107.8 mm, n = 7 in males and 92.7–107.0 mm, n = 6 in females vs 49.7–64.0 mm, n = 25 in males and 69.0–83.0 mm, n = 25 in females); males with nuptial spines on lower flanks, ventral surface of forelimbs, lower lip, throat, chest, 2 / 3 anterior part of belly (vs absent); males with nuptial spines on all fingers (vs absent); and the absence of nuptial spines around vent (vs present).

Etymology.

The new species is named in honor of our colleague and friend, Prof. Dr. Annemarie Ohler from the Département de Systématique et Evolution, Muséum National d’Histoire Naturelle, Paris, France, in recognition of her great contributions towards a better understanding of the amphibian systematics of the Indochinese region. We recommend “ Ohler’s Spiny Frog ” as the common English name of the new species and the common name in Vietnamese as “ Ếch gai s ần ohler ”.

Figures

Figure 7. Quasipaa ohlerae sp. nov., holotype (IEBR A. 5159, male) in life A dorsolateral view B ventral view.

Figure 8. Quasipaa ohlerae sp. nov., holotype (IEBR A. 5159, male) in preservative A dorsolateral view B ventral view. Scale bars: 10 mm

Figure 9. Quasipaa ohlerae sp. nov. A upper left hand of holotype (IEBR A. 5159, male) B lower right hand of holotype (IEBR A. 5159, male) C lower right foot of holotype (IEBR A. 5159, male) D iris of holotype (IEBR A. 5159, male) E eggs of paratype (IEBR A. 5160, female). Scale bar: 10 mm

Figure 10. Quasipaa ohlerae sp. nov., paratypes in life A dorsolateral view (IEBR A. 5161, male) B dorsolateral view (IEBR A. 5160, female).

Figure 11. Quasipaa ohlerae sp. nov., paratypes (IEBR A. 5160, female and IEBR A. 5161, male) in preservative A dorsolateral view B ventral view. Scale bars: 10 mm

Figure 12. Habitat of Quasipaa ohlerae sp. nov. in Xuan Lien Nature Reserve, Thanh Hoa Province, Viet Nam A microhabitat B evergreen forest.

Figure 13. Quasipaa delacouri in life A dorsolateral view B ventral view (IEBR A. 5017, male).

Figure 15. Quasipaa delacouri A lower left hand of male (IEBR A. 5017) B upper right hand of male (IEBR A. 5017) C iris of male (IEBR A. 5017) D lower right foot of male (IEBR A. 5017).