Description
Quasipaa taoi are relatively large frogs described from three males and three females with male snout-vent length ranging between 79.6 - 84.3 mm and female snout-vent length ranging between 64.6 - 69.9 mm. The head length is slightly shorter than width. In the dorsal view, the snout is rounded anteriorly and projects past the lower jaw. The nostril is lateral, positioned closer to the eye than the tip of the snout. The canthus rostralis is not clearly defined. The loreal region is oblique and a bit concave. The rostral length is greater than the eye diameter. The internarial distance is wider than both the interorbital distance and the upper eyelid width. The tympanum is moderately visible, and the distance from the tympanum to the eye is shorter than the distance from the eye to the nostril. There is a distinct supratympanic fold from the eye to the angle of the jaw. The dorsal surface of the head has round, ovular tubercles. The dorsum features six thick ridges interspersed with small, round tubercles. The dorsal surface of both the forelimbs and hind limbs is covered in small tubercles. The flanks are also covered in round, ovular tubercles. There are no dorsolateral folds. Quasipaa taoi lacks an external vocal sac. Both the belly and the ventral surface of the thighs are smooth. The arms are short. The internal metatarsal tubercle is round, while the outer metatarsal tubercle is elongated. No finger webbing is present and the relative finger length is as follows: III > IV > I > II. Fingers I, II, and III have dermal ridges on the sides. The fingertips are swollen but not enlarged. The subarticular tubercles are clearly defined and round. Finger I has a nuptial pad in males. The tibio-tarsal articulation extends to the tip of the snout when the hind limb is adpressed along the body. The tibia is longer than the thigh. The inner metatarsal tubercle is elongate, while the outer metatarsal tubercle is absent. Toes are fully webbed to the distal end of the terminal phalanx and the relative toe length is IV > III > V > II > I. Toes I and V have dermal ridges on the outer sides. The toe tips are slightly rounded and swollen. As in the fingers, the subarticular tubercles are prominent and elongate (Pham et al. 2022).

DIAGNOSIS:

Quasipaa taoi can be differentiated from congeners by a combination of several morphological characteristics. These include snout-vent length (a sexually dimorphic character), the ratio of head length to head width, the presence of vomerine teeth, the absence of external vocal sacs, a partially visible tympanum, a dorsum with thick ridges and small round tubercles, flanks with ovular and round tubercles, the presence of a supratympanic fold, the absence of a dorsolateral fold, toes webbed to the distal end of the terminal phalanx, and a dark brown dorsum with an immaculate white chest and belly in life. Additionally, in males, the presence of dark nuptial spines on the ventrolateral sides, the ventral surface of the arms, and all fingers, as well as the absence of spines on the chest and belly, help distinguish Quasipaa taoi from congeners (Pham et al. 2022).

Comparing Quasipaa taoi to specific congeners, Q. taoi can be differentiated from Q. boulengeri by its shorter snout-vent length; the latter has a snout-vent length range of 87.8 - 101.7 mm in males and 82.5 - 105.5 mm in females. Additionally, Q. taoi has thick ridges and round tubercles on its dorsum, as opposed to elongated ridges in Q. boulengeri. Quasipaa taoi has males with nuptial spines on each finger, while Q. boulengeri, males do not have nuptial spines on finger IV. Male Q. taoi also have nuptial spines on the throat and the ventral surface of the arms, whereas male Q. boulengeri do not. On the other hand, male Q. boulengeri have spines on the chest and belly, while male Q. taoi do not (Pham et al. 2022).

Quasipaa taoi differs from Q. acanthophora in that members of the latter species have small tubercles on the dorsum. Additionally, Q. acanthophora males lack nuptial spines on the ventrolateral sides, the ventral surface of arms, and finger IV, but possess spines on the chest (Pham et al. 2022).

Quasipaa taoi is smaller than Q. courtoisi, as the latter species has an average male snout-vent length of 126 mm. Male Q. courtoisi also lack nuptial spines on the throat and the ventral surface of the arms, unlike male Q. taoi. Male Q. courtoisi do, however, have spines on the chest, which male Q. taoi lack (Pham et al. 2022).

Quasipaa taoi is smaller than Q. delacouri; the latter has a snout-vent length range of 92.9 - 115.5 mm in males and 94.5 - 117.5 mm in females. Quasipaa taoi also has a higher ratio of tympanum diameter to eye diameter; in male Q. taoi the ratio is 0.44 ± 0.02 and in females it is 0.49 ± 0.01, whereas in male Q. delacouri the ratio is 0.26 and it is 0.24 in females. Quasipaa delacouri also has a smooth dorsum, and males lack nuptial spines, as well as a nuptial pad on finger I (Pham et al. 2022).

Quasipaa taoi is larger than Q. exilispinosa; average male snout-vent length in the latter is 61.2 mm and average female snout-vent length is 57.1 mm. Furthermore, Q. exilispinosa individuals have small tubercles on the dorsum and males do not have nuptial spines on the ventrolateral sides, the ventral surface of the arms, or finger IV. Male Q. exilispinosa do, however, have spines on the chest (Pham et al. 2022).

Quasipaa taoi is smaller Q. fasciculispina; males of the latter species have average snout-vent length of 106 mm and the average female snout-vent length is 104 mm. Quasipaa fasciculispina also has a larger relative tympanum compared to the distance between the tympanum and eye; male Q. taoi have a ratio of 1.11 ± 0.16 and females have a ratio of 1.2 ± 0.16, while Q. fasciculispina have ratios of 2.0 and 1.75, respectively. Males in the latter species also have circular whitish tubercles with 5 - 10 strong black spines each on the chest, while male Q. taoi have bare chests (Pham et al. 2022).

Quasipaa taoi differs from Q. jiulongensis in that the latter has small tubercles on the dorsum. Male Q. jiulongensis also lack nuptial spines on the ventrolateral sides, the ventral surface of the arms, and fingers III and IV. And Quasipaa jiulongensis has light-colored longitudinal stripes on the upper jaw edge as well as four or five yellow dots that line the dorsum in longitudinal rows, which Q. taoi lacks (Pham et al. 2022).

Quasipaa taoi differs from Q. robertingeri in that the latter has elongate ridges on the dorsum. Additionally, male Q. robertingeri lack nuptial spines on finger IV, the throat, and the ventral surface of the arms. This species does, however, have nuptial spines on the chest and belly, unlike Q. taoi (Pham et al. 2022).

Quasipaa taoi can be differentiated from Q. shini by their smaller size; males of the latter species have an average snout-vent length of 98.6 mm and females an average snout-vent length of 94.9 mm. Quasipaa shini also has elongate ridges on the dorsum, as opposed to thick ridges and round tubercles, and males lack nuptial spines on finger IV, the throat, and the ventral surface of the arms, unlike male Q. taoi. Male Q. shini have spines on the chest and belly, though, which male Q. taoi lack (Pham et al. 2022).

Quasipaa taoi can be differentiated from Q. spinosa by the former's shorter snout-vent lengths; male Q. spinosa have a snout-vent length range of 106.0 - 142.0 mm and females a snout-vent length range of 115.0 - 152.5 mm. Members of Q. spinosa also have small tubercles on their dorsum, as well as light-colored longitudinal stripes on the upper jaw edge, unlike Q. taoi. Furthermore, Q. spinosa males have small, dense nuptial spines on the chest, while Q. taoi males are bare-chested (Pham et al. 2022).

Quasipaa taoi varies from Q. verrucospinosa by its shorter snout-vent length; Q. verrucospinosa males have a snout-vent length range of 90.0 - 117.0 mm and female snout-vent length range is 83.2 - 113.9 mm. Additionally, male Q. verrucospinosa lack nuptial spines on fingers III and IV and on the ventral surface of the arms, although they do possess spines on the chest and belly (Pham et al. 2022).

Finally, Q. taoi is larger than Q. yei; Q. yei has a snout-vent length range of 49.7 - 64.0 mm. Also, male Q. yei lack nuptial spines on the ventrolateral sides, the ventral surface of the arms, and the fingers, but they do have spines around and inside the vent, unlike male Q. taoi (Pham et al. 2022).

COLORATION:

In life, the dorsum and upper flanks of Q. taoi are dark brown, as is the supratympanic fold. The lower flanks are whitish brown adorned with white tubercles and black spines. Dorsal surfaces of the limbs are yellowish brown with dark crossbars while the ventral surfaces of the limbs are light yellow with brown markings. The throat is white with brown markings. The chest and belly are both perfectly white. The toe webbing is dark brown. Coloration is slightly faded in preservative, but the overall color composition does not change (Pham et al. 2022).

VARIATION:

In males, dense nuptial spines cover the dorsum, flanks, ventral surface of forelimbs, ventrolateral sides, and fingers I and II. Smaller, sparse spines are also present on the throat, dorsal surface of fore- and hind limbs, and fingers III and IV (Pham et al. 2022).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Lao People's Democratic Republic, Viet Nam

View distribution map in BerkeleyMapper.

Quasipaa taoi is found in limited numbers in the Central Highlands of Vietnam, specifically in the Ngoc Linh Mountain, which has a maximum elevation of 2,598 m. It also has a very limited distribution in Xekong Province, Lao People’s Democratic Republic. Individuals are typically found in the waters of rocky streams or on the ground of adjacent banks at elevations above 1,500 m. The surrounding habitat is composed of secondary forest of hardwoods interspersed with shrubs and vines (Pham et al. 2022).

Life History, Abundance, Activity, and Special Behaviors
Quasipaa taoi has a restricted distribution throughout its geographical range (Pham et al. 2022).

Eggs of this species are yellowish-cream colored and differ in size, but average clutch size is not known (Pham et al. 2022).

Male advertisement calls and tadpoles have yet to be recorded or observed in the field (Pham et al. 2022).

Trends and Threats
Habitat loss by agricultural extension for medicinal trees, illegal timber logging, and tourism development all pose significant threats to Q. taoi. The continued survival of the species will be reliant upon conscientious management of the protected regions in both Vietnam and Laos (Pham et al. 2022).

Relation to Humans
Quasipaa taoi is collected by locals for food (Pham et al. 2022).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Intentional mortality (over-harvesting, pet trade or collecting)

Comments

PHYLOGENETIC RELATIONSHIPS:

The common English name for Q. taoi is “Tao’s Spiny Frog,” and the common Vietnamese name is “Ếch gai sần tạo” (Pham et al. 2022).

OTHER INTERESTING INFORMATION:

Quasipaa taoi is the thirteenth described species of its genus and the sixth described species of Quasipaa from Vietnam (Pham et al. 2022).

References
Pham, C. T., Hoang, C. V., Phan, T. Q., Nguyen, T. Q., and Ziegler, T. (2022). Hidden in the jungle of Vietnam: a new species of Quasipaa (Amphibia, Anura, Dicroglossidae) from Ngoc Linh Mountain. ZooKeys, 1124, 23–42. [link]

Species Account Citation: AmphibiaWeb 2024 Quasipaa taoi: English name: Tao's Spiny Frog; Vietnamese name: Ếch gai sần tạo <https://amphibiaweb.org/species/9581> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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