Tylototriton pasmansi obsti 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 obsti M. Bernardes, M. D. Le, T. Q. Nguyen, C.T. Pham, A. V. Pham, T.T. Nguyen & T. Ziegler ssp. nov. Figures 9 , 10

Tylototriton taxon 1 (this study).

Holotype.

IEBR 4471, adult male, collected in Xuan Nha Nature Reserve, Van Ho District, Son La Province, at an elevation of 1090 m a.s.l., on 15 June 2016 by A. V. Pham and N. B. Sung.

Paratypes.

Eight adult males, the same data as the holotype: IEBR 4472-4475, TBU 11-14; two adult males collected at elevation of 950 m a.s.l. in Xuan Lien Nature Reserve, Vin Village, Bat Mot Commune, Thuong Xuan District, Thanh Hoa Province, and in July 2015 by T. S. Nguyen: IEBR 4318 and IEBR 4319.

Etymology.

The new subspecies is named after Prof. Fritz-Jürgen Obst, the former herpetologist and director of the Museum für Tierkunde Dresden, Germany, as well as passionate Tylototriton keeper, who passed away on the 10 June 2018.

Diagnosis.

The new subspecies is diagnosed from the nominotypic subspecies Tylototriton pasmansi pasmansi by the following combination of characters: a wider head (both as head width and maximum head width), versus narrower head; a longer and narrower snout, versus shorter and wider snout; a shorter femur and associated hind-limb lengths, versus longer femur and longer hind-limbs length; less overall concentration of warts and small granules on skin, versus overall skin more granulose; and skin on lateral body with apparently same concentration of warts than dorsal side, versus higher concentration of warts on ventral side of the body than on dorsum in T. p. pasmansi .

Description of holotype.

Habitus moderately stout; 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 not 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 thin and scrolled inside; distinct middorsal ridge on head; parotoids enlarged, projecting backwards; dorsal skin granulose; skin on lateral body and between axilla-groin smooth, with no obvious presence of small glands; throat skin visibly more rough than in between axilla-groin region; gular fold present; glandular vertebral ridge high, slightly rough and segmented, anteriorly thinner, extending from top of head to base of tail, separated from middorsal ridge; number of trunk vertebrae 12; rib nodules distinct, rounded and pointy, with similar sizes throughout their length; fingers from fore- and hind limbs overlap when adpressed along body; tips of fingers reaching eye when adpressed along head; and tail laterally compressed, thin and tip acuminated.

Color of holotype.

In preservative, with overall dark brown to blackish with faded yellow markings in vent margin, ventral tail fin, and tips of fingers and toes. For color in life see Fig. 9 .

Measurements of holotype (in mm).

SVL 67.95; MHW 18.1; HW 12.53; HL 19.44; PL 10.4; PH 5.5; EL 3.4; EN 3.99; IN 5.44; IE 8.64; LJL 12.11; UEL 5.07; HUM 8.12; RAD 14.43; FEM 7.05; TIB 15.75; FORE 22.55; HIND 22.80; TL 60.71; TH 8.46; ClL 8.86; ClW 5.88; WVr 2.18; L5W 2.12; AG 30.57; and TkL 46.48.

Variation (based on preserved paratypes).

Some paratypes also show slightly bigger and rounded rib nodules, an overall more granulose skin, and faded yellow coloration on: anterior upper arms (like mating pads), posterior end of parotoids and first rib nodules. The remaining characters were similar to the holotype. Further measurements are summarized in Table 4 .

Comparisons.

In addition to the diagnostic characteristics already mentioned above, Tylototriton pasmansi obsti ssp. nov. differs from T. p. pasmansi by having a moderately stout habitus (versus moderately slender, when excluding the population from Phu Tho), nostrils usually not visible (versus usually visible) from dorsal view, usually thinner (versus usually thicker) posterior end of the dorsolateral bony ridges on head, gular fold more evident (versus weaker), rib nodules with similar sizes throughout their length (versus with slightly bigger sizes at mid-trunk), and rib nodules sometimes pointy (versus rounded in T. p. pasmansi ).

Distribution.

Xuan Nha Nature Reserve, Van Ho District, Son La Province and Xuan Lien Nature Reserve, Thuong Xuan District, Thanh Hoa Province, Vietnam (Fig. 2 ).

Natural history.

Specimens were found between 14:00 and 16:00 h inside breeding ponds. The surrounding habitat was characterized by secondary forest of large, medium and small hardwoods mixed with shrubs and vines. Air temperature at the collection time was about 25 to 30 oC and relative humidity was about 75 to 80 %. Based on remote sensing information the species occurs at sites with an annual mean temperature of 19.9 to 20.4 °C, ranging from 11.7 to 27.1 °C during the year. Annual precipitation is about 1603.5 to 1648.3 mm with yearly variations from 4.3 to 373.0 mm monthly. 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 10. Tylototriton pasmansi obsti ssp. nov. (holotype) In sequence: dorsal view; ventral view; lateral view; and detail of dorsal view of the head. Photographs T. Ziegler.