Tylototriton pasmansi M. Bernardes, M. D. Le, T. Q. Nguyen, C. T. Pham, A. V. Pham, T.T. Nguyen & T. Ziegler, 2020

Bernardes, Marta, Le, Minh Duc, Nguyen, Truong Quang, Pham, Cuong The, Pham, Anh Van, Nguyen, Tao Thien, Roedder, Dennis, Bonkowski, Michael & Ziegler, Thomas, 2020, Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam, ZooKeys 935, pp. 121-164 : 121

Tylototriton pasmansi M. Bernardes, M. D. Le, T. Q. Nguyen, C. T. Pham, A. V. Pham, T.T. Nguyen & T. Ziegler sp. nov. Figures 8 , 9

Tylototriton taxon 2 (this study).

T. vietnamensis (referring to the population from Phu Tho Province): Nguyen et al. 2009, page 327.

T. asperrimus (referring to the population from Hoa Binh Province): Yuan et al. 2011, page 583; Nishikawa et al. 2013b, page 39; Luu et al. 2014, page 55.

T. cf. asperrimus (1) (referring to the population from Hoa Binh Province): Phimmachak et al. 2015a, page 293.

T. cf. asperrimus "Lao Cai/Hoa Binh" (referring to the populations from Lac Son, Hoa Binh): Hernandez 2016, page 254.

T. cf. asperrimus "northern Vietnam" (referring to the populations from Lai Chau, Lao Cai, Hoa Binh, and Phu Tho) Hernandez 2018, page 80.

Holotype.

IEBR 4466, adult male, collected in Phu Canh Nature Reserve, Da Bac District, Hoa Binh Province, on 11 June 2016 by H. N. Ngo et al.

Paratypes.

Four adult males, same data as the holotype: IEBR 4467-IEBR 4470; two adult males collected from Xuan Son National Park, Tan Son District, Phu Tho Province, unknown collector: IEBR 4322 and IEBR 4323; four adult males collected from Xuan Son National Park, Tan Son District, Phu Tho Province, on 7 July 2016 by T. D. Le: IEBR 4320, IEBR 4321, IEBR 4500 and IEBR 4501. One adult female collected from Thuong Tien Nature Reserve (Cot Ca forest, Quy Hoa Commune), Lac Son District, Hoa Binh Province at 720 m elevation on 24 July 2009 by V. Q. Luu: VFU A.2009.8.

Etymology.

The species is named after Prof. Dr. Frank Pasmans, Ghent University (Belgium), who has made considerable and path-breaking contributions in the field of infectious diseases driven amphibian declines.

Diagnosis.

The new species is diagnosed by the following combination of characters: head slightly longer than wide; snout truncate in dorsal view and slightly angular in profile; relative wide distance between the eyes; distinct mid-dorsal ridge on head; tips of fingers reaching the eye when foreleg adpressed along head; labial and gular folds present; rib nodules distinct and varying from pointy to more rounded; glandular vertebral ridge high, slightly rough and segmented; dorsal skin more granulose than ventral skin; and skin in middle of abdomen with smooth tubercles shaped like transverse wrinkles.

Description of holotype.

Habitus moderately slender; head broader than body, slightly longer than wide, depressed and slightly oblique in profile; snout wider than long (IN> EN), truncate in dorsal view, slightly angular shaped in profile and protruding beyond lower jaw; nostrils close to snout tip and slightly visible from above; labial fold slightly evident; dorsolateral bony ridges on head prominent, moderately protruding, from above eye to above anterior end of parotoid, posterior ends relatively thick and scrolled inside; mid-dorsal ridge on head distinct and thin; parotoids enlarged, projecting backwards; ventral skin with tubercles shaped like transverse wrinkles; gular fold weak; glandular vertebral ridge high, slightly rough and segmented, anteriorly thinner, extending from top of head to base of tail, separated from mid-dorsal ridge, with slight scoliosis at height of anterior limbs; number of trunk vertebras around 13; rib nodules distinct, rounded and small, with slightly bigger sizes reached at mid-trunk; tips of fore- and hind limbs touch when adpressed along body; tips of fingers reaching eye when foreleg laid forward; one toe missing on right hind-limb; and tail laterally compressed, thin and tip acuminated.

Color of holotype.

In preservative, the overall dorsal coloration faded dark grayish green, the ventral coloration dark brown, with faded yellow markings on vent, ventral margin of tail, tip of fingers and toes, and part of palms. For color in life see Fig. 9 .

Measurements of holotype (in mm).

SVL 64.16; MHW 16.07; HW 11.87; HL 17.67; PL 9.61; PH 4.50; EL 3.06; EN 3.69; IN 5.55; IE 8.11; LJL 10.8; UEL 4.52; HUM 5.97; RAD 13.51; FEM 7.44; TIB 13.70; FORE 19.48; HIND 21.14; TL 53.91; TH 7.78; ClL 8.13; ClW 4.37; WVr 2.18; L5W 2.31; AG 27.36; and TkL 44.00.

Variation.

Paratypes from Hoa Binh Province are very similar to the holotype. Paratypes from Phu Tho seem to present a stouter habitus, more distinct middorsal ridge but slightly less protruding dorsolateral ridges on head and slightly enlarged round rib nodules. The variation of the morphological characters in males is summarized in Table 4 and the additional measurements of one female can be found in Table 3 .

Comparisons.

Tylototriton pasmansi sp. nov. differs from other related species of Tylototriton as follows: from T. anhuiensis by distinctly separated rib nodules (versus continuous nodule-like warts in T. anhuiensis ); from T. asperrimus by a wider (versus shorter) distance between the eyes, tips of fingers reaching eye (versus nostril) when foreleg laid forward, and head slightly longer than wide (versus wider than long in T. asperrimus according to Nishikawa et al. 2013b; Sparreboom 2014; Hernandez 2016), however, the female holotype shows similar head proportions-see Discussion); from T. broadoridgus by a head longer than wide (versus equally long and wide), wider (versus shorter) distance between eyes, presence (versus absence) of gular fold, smoother (versus extremely rough) skin on ventral side shaped like transverse wrinkles (versus rounded shaped, uniform to dorsal side), distinctly separated rib nodules (versus continuous nodule-like warts), and narrower vertebral ridge (versus broader in T. broadoridgus ); from T. hainanensis by the head being slightly longer than wide (versus much wider than long), and a snout truncate in dorsal view (versus rounded in T. hainanensis ); from T. liuyangensis by a wider (versus shorter) distance between eyes, distinctly separated rib nodules (versus continuous nodule-like warts), and ventral side skin shaped like transverse wrinkles (versus covered by warts in T. liuyangensis ); from T. notialis by a broader (versus narrower) head, a slightly angular (versus rounded) shaped snout in profile, longer (versus shorter) hind-limbs, and higher tail (versus thinner tail in T. notialis ); from T. panhai by wider (versus shorter) distance between the eyes, presence (versus absence) of labial fold, distinct (versus absent) middorsal ridge on head, and dorsal color uniformly dark (versus dorsal color with characteristic colorful markings in T. panhai ); from T. vietnamensis by round to pointy (versus slightly flattened) rib nodules, presence (versus absence) of gular fold, and high vertebral ridge (versus low vertebral ridge in T. vietnamensis ); from T. wenxianensis by a truncate snout in dorsal view (versus round), wider (versus shorter) distance between the eyes, distinctly separated rib nodules (versus continuous nodule-like warts), presence (versus absence) of gular fold, smoother (versus extremely rough) skin on ventral side shaped like transverse wrinkles (versus rounded shaped and uniform to dorsal side), and colored marking on ventral slit (versus black colored ventral slit in T. wenxianensis ); and from T. ziegleri by head slightly longer than wide (versus wider than long), smaller (versus enlarged knob-like) rib nodules, dispersed granules (versus more granulose) on dorsal skin and vertebral ridge slightly less (versus more) segmented and glandular.

The morphological comparison resulting from the measurements performed on the two females of T. pasmansi and T. asperrimus sensu stricto (Table 3 ) showed that the first one presents: wider (versus narrower) and longer (versus less long) head, longer (versus shorter) lower jaw length, wider (versus shorter) distance between the eyes, as well as higher values for all of the remaining head features, with the exception of snout length and head width, which were, in these cases, higher in T. asperrimus . T. pasmansi additionally presents longer and higher (versus shorter and thinner) tail, bigger (versus smaller) cloacal muscles, wider (versus narrower) vertebral ridge, slightly bigger (versus smaller) rib nodules and shorter trunk length (versus longer trunk length in T. asperrimus ).

Distribution.

Phu Canh Nature Reserve, Da Bac District and Thuong Tien Nature Reserve, Lac Son District in Hoa Binh Province, and Xuan Son National Park, Tan Son District, Phu Tho Province, Vietnam (Fig. 2 ).

Natural history.

Based on remote sensing information the species is known from sites with an annual mean temperature of 20.4 to 20.7 °C, ranging from 11.5 to 26.3 °C during the year. Annual precipitation is about 1624 to 1884 mm ranging throughout the year from 7.3 to 379.8 mm. Further bioclimatic information is provided in Table 6 .

Figures

Figure 2. Distribution map of the new populations of Tylototriton from North Vietnam, based on the following symbols: square (taxon 3, this study) the population from Sin Ho District, Lai Chau Province; diamond (taxon 1, this study) the upper one identifies the population from Van Ho District, Son La Province, and the lower one identifies the population from Thuong Xuan District, Thanh Hoa Province; triangle (taxon 2, this study) the upper one identifies the population from Tan Son District, Phu Tho Province, the middle one identifies the population from Da Bac District, Hoa Binh Province, and the lower one identifies the population from Lac Son District, Hoa Binh Province. The two populations identified by the circles represent T. asperrimus sensu stricto from China. High resolution remote sensing land cover information was extracted from " GLAD-UMD and SERVIR-Mekong, Natural annual tree canopy structure and surface water dynamics products, 2017 " (lower left panel). Bioclimatic variables (right side) were extracted from remote sensing data provided by Deblauwe et al. (2016).

Figure 8. Tylototriton pasmansi sp. nov. (holotype). In sequence: dorsal view; ventral view; lateral view; and detail of dorsal view of the head. Photographs T. Ziegler.

Figure 9. Dorsal and ventral views of the new taxa in life. Top: Tylototriton pasmansi sp. nov. (holotype); Center: Tylototriton pasmansi obsti ssp. nov. (holotype); Bottom: Tylototriton sparreboomi sp. nov. Photographs: C. T. Pham (upper row) and A. V. Pham (central and lower rows).