Tylototriton sparreboomi 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 sparreboomi M. Bernardes, M. D. Le, T. Q. Nguyen, C. T. Pham, A. V. Pham, T.T. Nguyen & T. Ziegler sp. nov. Figures 9 , 11

Tylototriton taxon 3 (this study).

T. sp.: Laking et al. 2017, page 2.

T. verrucosus : Orlov et al. 2002, page 101; van Dijk et al. 2009, page 1; Nguyen et al. 2009, page 329.

T. cf. asperrimus "North Vietnam": Hernandez 2018, page 80.

Holotype.

IEBR 4476, adult male, collected in Sa De Phin Commune, Sin Ho District, Lai Chau Province, Vietnam, at an elevation of 1670 m a.s.l., in May 2015 by A. V. Pham and M. A. Vang.

Paratypes.

Two adult males, same data as the holotype: IEBR 4477 and TBU 10; two adult males, collector unknown: IEBR 4478 and IEBR 4479.

Etymology.

The specific epithet is dedicated to late Prof. Dr. Max Sparreboom, who has made great contributions to the understanding of Urodela .

Diagnosis.

The new species is distinguished from other species of the genus by the following combination of characters: head longer than wide; snout truncate in dorsal view; tips of fingers reaching nostril when foreleg is laid forward; skin tubercles on ventral side shaped like transverse wrinkles; rib nodules distinct and round; vertebral ridge segmented, high and relatively wide; relatively wide distance between the eyes; and gular and labial folds present.

Description of holotype.

Habitus stout; head broader than body, longer than wide, depressed and slightly oblique in profile; snout wider than long (IN> EN), truncate in dorsal view, rounded in profile and protruding beyond lower jaw; nostrils close to snout tip and not visible from above; labial fold slightly evident; dorsolateral bony ridges on head prominent, wide, moderately protruding, from above eye to above anterior end of parotoid, posterior ends slightly scrolled inside; middorsal ridge on head almost indistinct; parotoids enlarged, projecting backwards; ventral skin smoother than dorsal skin, with tubercles shaped like transverse wrinkles; gular fold weak; glandular vertebral ridge high, wide, smooth and segmented extending from top of head to base of tail, separated from middorsal ridge; number of trunk vertebrae 13; rib nodules distinct and roundish, the third anterior rib nodule on right side is located below the second nodule and the fourth nodule seems to not be associated with the fourth vertebra, nodules appear knob-like anteriorly, becoming smaller posteriorly; tips of fore- and hind limbs overlap when adpressed along body; tips of fingers reaching nostril when foreleg laid forward; and tail laterally compressed, thin and tip acuminated.

Color of holotype.

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

Measurements of holotype (in mm).

SVL 68.71; MHW 17.60; HW 9.85; HL 19.95; PL 10.18; PH 6.12; EL 3.43; EN 4.43; IN 6.26; IE 9.04; LJL 10.74; UEL 4.74; HUM 9.27; RAD 15.86; FEM 8.77; TIB 16.03; TL 59.70; TH 8.57; ClL 9.66; WVr 2.37; L5W 3.04; AG 30.99; and TkL 42.72.

Variation.

TBU 10 (in worse preserved condition) presents rib-nodules thinner than holotype, glandular vertebral ridge more tubercular, and tail tip slightly rounded. The remaining characters were similar to the holotype in morphology. For detailed measurements see Table 4 .

Comparisons.

Tylototriton sparreboomi 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 head 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 head slightly longer than wide (versus equally long and wide), presence of skin on ventral side shaped like transverse wrinkles (versus covered with round shaped tubercles, like the dorsal side), distinctly separated rib nodules (versus continuous nodule-like warts), and narrower vertebral ridge (versus wider vertebral ridge in T. broadoridgus ); from T. hainanensis by a head longer than wide (versus much wider than long), tips of fingers reaching nostril (versus eyes) when foreleg is laid forward, 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 lateral skin shaped like transverse wrinkles (versus covered by warts in T. liuyangensis ); from T. notialis by a broader (versus narrower) head, 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, and overall dorsal coloration mostly dark (versus with presence of characteristic dorsal colorful markings in T. panhai ); from T. pasmansi sensu lato by a narrower (versus wider) head, slightly wider (versus slightly narrower) distance between the eyes, tips of fingers reaching nostril (versus eye) when foreleg laid forward, longer (versus shorter) humerus length, and slightly enlarged round-like rib nodules (versus slightly smaller, pointy to rounded rib nodules in T. pasmansi sensu lato); from T. p. pasmansi by a longer (versus shorter) length between eye and nostril and wider (versus narrower) vertebral ridge in T. p. pasmansi ; from T. pasmansi obsti by a longer (versus shorter) femur length; from T. vietnamensis by a moderately stout (versus slender) habitus, presence (versus absence) of gular fold, and round (versus slightly flattened) rib nodules and high vertebral ridge (versus low vertebral ridge in T. vietnamensis ); from T. wenxianensis by a truncate (versus more rounded) snout in dorsal view, wider (versus narrower) distance between the eyes, distinctly separated rib nodules (versus continuous nodule-like warts), 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 ); from T. ziegleri by a head longer than wide (versus wider than long), rounded but smaller (versus enlarged knob-like) rib nodules, and distinctly segmented vertebral ridge (versus even more segmented vertebral ridge in T. ziegleri ).

Distribution.

Known only from the type locality in Lai Chau Province, northern Vietnam (Fig. 2 ).

Natural history.

Specimens were found in water between 9:00 and 16:30 h in ponds. The surrounding habitat was secondary forest of large, medium and small hardwoods mixed with shrubs and vines. Air temperature at the sites was 23 to 27 °C and relative humidity was 80 to 85%. Based on remote sensing information, the species occurs at sites with an annual mean temperature of 19.3 °C, ranging from 11.6 to 26.1 °C during the year. Annual precipitation is about 1843.7 mm with yearly variations from 9.6 to 421.6 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 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).

Figure 11. Tylototriton sparreboomi sp. nov. (holotype). In sequence: dorsal view; ventral view; lateral view; and detail of dorsal view of the head. Photographs T. Ziegler.